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Signed-off-by: Shiraz Hashim <quic_shashim@quicinc.com>
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The ieee80211 skb control block key (set when skb was queued) could have
been removed before ieee80211_tx_dequeue() call. ieee80211_tx_dequeue()
already called ieee80211_tx_h_select_key() to get the current key, but
the latter do not update the key in skb control block in case it is
NULL. Because some drivers actually use this key in their TX callbacks
(e.g. ath1{1,2}k_mac_op_tx()) this could lead to the use after free
below:
BUG: KASAN: slab-use-after-free in ath11k_mac_op_tx+0x590/0x61c
Read of size 4 at addr ffffff803083c248 by task kworker/u16:4/1440
CPU: 3 UID: 0 PID: 1440 Comm: kworker/u16:4 Not tainted 6.13.0-ge128f627f404 #2
Hardware name: HW (DT)
Workqueue: bat_events batadv_send_outstanding_bcast_packet
Call trace:
show_stack+0x14/0x1c (C)
dump_stack_lvl+0x58/0x74
print_report+0x164/0x4c0
kasan_report+0xac/0xe8
__asan_report_load4_noabort+0x1c/0x24
ath11k_mac_op_tx+0x590/0x61c
ieee80211_handle_wake_tx_queue+0x12c/0x1c8
ieee80211_queue_skb+0xdcc/0x1b4c
ieee80211_tx+0x1ec/0x2bc
ieee80211_xmit+0x224/0x324
__ieee80211_subif_start_xmit+0x85c/0xcf8
ieee80211_subif_start_xmit+0xc0/0xec4
dev_hard_start_xmit+0xf4/0x28c
__dev_queue_xmit+0x6ac/0x318c
batadv_send_skb_packet+0x38c/0x4b0
batadv_send_outstanding_bcast_packet+0x110/0x328
process_one_work+0x578/0xc10
worker_thread+0x4bc/0xc7c
kthread+0x2f8/0x380
ret_from_fork+0x10/0x20
Allocated by task 1906:
kasan_save_stack+0x28/0x4c
kasan_save_track+0x1c/0x40
kasan_save_alloc_info+0x3c/0x4c
__kasan_kmalloc+0xac/0xb0
__kmalloc_noprof+0x1b4/0x380
ieee80211_key_alloc+0x3c/0xb64
ieee80211_add_key+0x1b4/0x71c
nl80211_new_key+0x2b4/0x5d8
genl_family_rcv_msg_doit+0x198/0x240
<...>
Freed by task 1494:
kasan_save_stack+0x28/0x4c
kasan_save_track+0x1c/0x40
kasan_save_free_info+0x48/0x94
__kasan_slab_free+0x48/0x60
kfree+0xc8/0x31c
kfree_sensitive+0x70/0x80
ieee80211_key_free_common+0x10c/0x174
ieee80211_free_keys+0x188/0x46c
ieee80211_stop_mesh+0x70/0x2cc
ieee80211_leave_mesh+0x1c/0x60
cfg80211_leave_mesh+0xe0/0x280
cfg80211_leave+0x1e0/0x244
<...>
Reset SKB control block key before calling ieee80211_tx_h_select_key()
to avoid that.
Fixes: bb42f2d ("mac80211: Move reorder-sensitive TX handlers to after TXQ dequeue")
Signed-off-by: Remi Pommarel <repk@triplefau.lt>
Link: https://patch.msgid.link/06aa507b853ca385ceded81c18b0a6dd0f081bc8.1742833382.git.repk@triplefau.lt
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
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SMC consists of two sockets: smc_sock and kernel TCP socket. Currently, there are two ways of creating the sockets, and syzbot reported a lockdep splat [0] for the newer way introduced by commit d25a92c ("net/smc: Introduce IPPROTO_SMC"). socket(AF_SMC , SOCK_STREAM, SMCPROTO_SMC or SMCPROTO_SMC6) socket(AF_INET or AF_INET6, SOCK_STREAM, IPPROTO_SMC) When a socket is allocated, sock_lock_init() sets a lockdep lock class to sk->sk_lock.slock based on its protocol family. In the IPPROTO_SMC case, AF_INET or AF_INET6 lock class is assigned to smc_sock. The repro sets IPV6_JOIN_ANYCAST for IPv6 UDP and SMC socket and exercises smc_switch_to_fallback() for IPPROTO_SMC. 1. smc_switch_to_fallback() is called under lock_sock() and holds smc->clcsock_release_lock. sk_lock-AF_INET6 -> &smc->clcsock_release_lock (sk_lock-AF_SMC) 2. Setting IPV6_JOIN_ANYCAST to SMC holds smc->clcsock_release_lock and calls setsockopt() for the kernel TCP socket, which holds RTNL and the kernel socket's lock_sock(). &smc->clcsock_release_lock -> rtnl_mutex (-> k-sk_lock-AF_INET6) 3. Setting IPV6_JOIN_ANYCAST to UDP holds RTNL and lock_sock(). rtnl_mutex -> sk_lock-AF_INET6 Then, lockdep detects a false-positive circular locking, .-> sk_lock-AF_INET6 -> &smc->clcsock_release_lock -> rtnl_mutex -. `-----------------------------------------------------------------' but IPPROTO_SMC should have the same locking rule as AF_SMC. sk_lock-AF_SMC -> &smc->clcsock_release_lock -> rtnl_mutex -> k-sk_lock-AF_INET6 Let's set the same lock class for smc_sock. Given AF_SMC uses the same lock class for SMCPROTO_SMC and SMCPROTO_SMC6, we do not need to separate the class for AF_INET and AF_INET6. [0]: WARNING: possible circular locking dependency detected 6.14.0-rc3-syzkaller-00267-gff202c5028a1 #0 Not tainted syz.4.1528/11571 is trying to acquire lock: ffffffff8fef8de8 (rtnl_mutex){+.+.}-{4:4}, at: ipv6_sock_ac_close+0xd9/0x110 net/ipv6/anycast.c:220 but task is already holding lock: ffff888027f596a8 (&smc->clcsock_release_lock){+.+.}-{4:4}, at: smc_clcsock_release+0x75/0xe0 net/smc/smc_close.c:30 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (&smc->clcsock_release_lock){+.+.}-{4:4}: __mutex_lock_common kernel/locking/mutex.c:585 [inline] __mutex_lock+0x19b/0xb10 kernel/locking/mutex.c:730 smc_switch_to_fallback+0x2d/0xa00 net/smc/af_smc.c:903 smc_sendmsg+0x13d/0x520 net/smc/af_smc.c:2781 sock_sendmsg_nosec net/socket.c:718 [inline] __sock_sendmsg net/socket.c:733 [inline] ____sys_sendmsg+0xaaf/0xc90 net/socket.c:2573 ___sys_sendmsg+0x135/0x1e0 net/socket.c:2627 __sys_sendmsg+0x16e/0x220 net/socket.c:2659 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #1 (sk_lock-AF_INET6){+.+.}-{0:0}: lock_sock_nested+0x3a/0xf0 net/core/sock.c:3645 lock_sock include/net/sock.h:1624 [inline] sockopt_lock_sock net/core/sock.c:1133 [inline] sockopt_lock_sock+0x54/0x70 net/core/sock.c:1124 do_ipv6_setsockopt+0x2160/0x4520 net/ipv6/ipv6_sockglue.c:567 ipv6_setsockopt+0xcb/0x170 net/ipv6/ipv6_sockglue.c:993 udpv6_setsockopt+0x7d/0xd0 net/ipv6/udp.c:1850 do_sock_setsockopt+0x222/0x480 net/socket.c:2303 __sys_setsockopt+0x1a0/0x230 net/socket.c:2328 __do_sys_setsockopt net/socket.c:2334 [inline] __se_sys_setsockopt net/socket.c:2331 [inline] __x64_sys_setsockopt+0xbd/0x160 net/socket.c:2331 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #0 (rtnl_mutex){+.+.}-{4:4}: check_prev_add kernel/locking/lockdep.c:3163 [inline] check_prevs_add kernel/locking/lockdep.c:3282 [inline] validate_chain kernel/locking/lockdep.c:3906 [inline] __lock_acquire+0x249e/0x3c40 kernel/locking/lockdep.c:5228 lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5851 __mutex_lock_common kernel/locking/mutex.c:585 [inline] __mutex_lock+0x19b/0xb10 kernel/locking/mutex.c:730 ipv6_sock_ac_close+0xd9/0x110 net/ipv6/anycast.c:220 inet6_release+0x47/0x70 net/ipv6/af_inet6.c:485 __sock_release net/socket.c:647 [inline] sock_release+0x8e/0x1d0 net/socket.c:675 smc_clcsock_release+0xb7/0xe0 net/smc/smc_close.c:34 __smc_release+0x5c2/0x880 net/smc/af_smc.c:301 smc_release+0x1fc/0x5f0 net/smc/af_smc.c:344 __sock_release+0xb0/0x270 net/socket.c:647 sock_close+0x1c/0x30 net/socket.c:1398 __fput+0x3ff/0xb70 fs/file_table.c:464 task_work_run+0x14e/0x250 kernel/task_work.c:227 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop kernel/entry/common.c:114 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x27b/0x2a0 kernel/entry/common.c:218 do_syscall_64+0xda/0x250 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f other info that might help us debug this: Chain exists of: rtnl_mutex --> sk_lock-AF_INET6 --> &smc->clcsock_release_lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&smc->clcsock_release_lock); lock(sk_lock-AF_INET6); lock(&smc->clcsock_release_lock); lock(rtnl_mutex); *** DEADLOCK *** 2 locks held by syz.4.1528/11571: #0: ffff888077e88208 (&sb->s_type->i_mutex_key#10){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:877 [inline] #0: ffff888077e88208 (&sb->s_type->i_mutex_key#10){+.+.}-{4:4}, at: __sock_release+0x86/0x270 net/socket.c:646 #1: ffff888027f596a8 (&smc->clcsock_release_lock){+.+.}-{4:4}, at: smc_clcsock_release+0x75/0xe0 net/smc/smc_close.c:30 stack backtrace: CPU: 0 UID: 0 PID: 11571 Comm: syz.4.1528 Not tainted 6.14.0-rc3-syzkaller-00267-gff202c5028a1 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Call Trace: <TASK> __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 print_circular_bug+0x490/0x760 kernel/locking/lockdep.c:2076 check_noncircular+0x31a/0x400 kernel/locking/lockdep.c:2208 check_prev_add kernel/locking/lockdep.c:3163 [inline] check_prevs_add kernel/locking/lockdep.c:3282 [inline] validate_chain kernel/locking/lockdep.c:3906 [inline] __lock_acquire+0x249e/0x3c40 kernel/locking/lockdep.c:5228 lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5851 __mutex_lock_common kernel/locking/mutex.c:585 [inline] __mutex_lock+0x19b/0xb10 kernel/locking/mutex.c:730 ipv6_sock_ac_close+0xd9/0x110 net/ipv6/anycast.c:220 inet6_release+0x47/0x70 net/ipv6/af_inet6.c:485 __sock_release net/socket.c:647 [inline] sock_release+0x8e/0x1d0 net/socket.c:675 smc_clcsock_release+0xb7/0xe0 net/smc/smc_close.c:34 __smc_release+0x5c2/0x880 net/smc/af_smc.c:301 smc_release+0x1fc/0x5f0 net/smc/af_smc.c:344 __sock_release+0xb0/0x270 net/socket.c:647 sock_close+0x1c/0x30 net/socket.c:1398 __fput+0x3ff/0xb70 fs/file_table.c:464 task_work_run+0x14e/0x250 kernel/task_work.c:227 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop kernel/entry/common.c:114 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x27b/0x2a0 kernel/entry/common.c:218 do_syscall_64+0xda/0x250 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f8b4b38d169 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffe4efd22d8 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 00000000000b14a3 RCX: 00007f8b4b38d169 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00007f8b4b5a7ba0 R08: 0000000000000001 R09: 000000114efd25cf R10: 00007f8b4b200000 R11: 0000000000000246 R12: 00007f8b4b5a5fac R13: 00007f8b4b5a5fa0 R14: ffffffffffffffff R15: 00007ffe4efd23f0 </TASK> Fixes: d25a92c ("net/smc: Introduce IPPROTO_SMC") Reported-by: syzbot+be6f4b383534d88989f7@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=be6f4b383534d88989f7 Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Reviewed-by: Wenjia Zhang <wenjia@linux.ibm.com> Link: https://patch.msgid.link/20250407170332.26959-1-kuniyu@amazon.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Ido Schimmel says: ==================== fib_rules: Fix iif / oif matching on L3 master device Patch #1 fixes a recently reported regression regarding FIB rules that match on iif / oif being a VRF device. Patch #2 adds test cases to the FIB rules selftest. ==================== Link: https://patch.msgid.link/20250414172022.242991-1-idosch@nvidia.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Communicating with the hypervisor using the shared GHCB page requires clearing the C bit in the mapping of that page. When executing in the context of the EFI boot services, the page tables are owned by the firmware, and this manipulation is not possible. So switch to a different API for accepting memory in SEV-SNP guests, one which is actually supported at the point during boot where the EFI stub may need to accept memory, but the SEV-SNP init code has not executed yet. For simplicity, also switch the memory acceptance carried out by the decompressor when not booting via EFI - this only involves the allocation for the decompressed kernel, and is generally only called after kexec, as normal boot will jump straight into the kernel from the EFI stub. Fixes: 6c32117 ("x86/sev: Add SNP-specific unaccepted memory support") Tested-by: Tom Lendacky <thomas.lendacky@amd.com> Co-developed-by: Tom Lendacky <thomas.lendacky@amd.com> Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com> Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: <stable@vger.kernel.org> Cc: Dionna Amalie Glaze <dionnaglaze@google.com> Cc: Kevin Loughlin <kevinloughlin@google.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: linux-efi@vger.kernel.org Link: https://lore.kernel.org/r/20250404082921.2767593-8-ardb+git@google.com # discussion thread #1 Link: https://lore.kernel.org/r/20250410132850.3708703-2-ardb+git@google.com # discussion thread #2 Link: https://lore.kernel.org/r/20250417202120.1002102-2-ardb+git@google.com # final submission
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There is a potential deadlock if we do report zones in an IO context, detailed in below lockdep report. When one process do a report zones and another process freezes the block device, the report zones side cannot allocate a tag because the freeze is already started. This can thus result in new block group creation to hang forever, blocking the write path. Thankfully, a new block group should be created on empty zones. So, reporting the zones is not necessary and we can set the write pointer = 0 and load the zone capacity from the block layer using bdev_zone_capacity() helper. ====================================================== WARNING: possible circular locking dependency detected 6.14.0-rc1 #252 Not tainted ------------------------------------------------------ modprobe/1110 is trying to acquire lock: ffff888100ac83e0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: __flush_work+0x38f/0xb60 but task is already holding lock: ffff8881205b6f20 (&q->q_usage_counter(queue)#16){++++}-{0:0}, at: sd_remove+0x85/0x130 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (&q->q_usage_counter(queue)#16){++++}-{0:0}: blk_queue_enter+0x3d9/0x500 blk_mq_alloc_request+0x47d/0x8e0 scsi_execute_cmd+0x14f/0xb80 sd_zbc_do_report_zones+0x1c1/0x470 sd_zbc_report_zones+0x362/0xd60 blkdev_report_zones+0x1b1/0x2e0 btrfs_get_dev_zones+0x215/0x7e0 [btrfs] btrfs_load_block_group_zone_info+0x6d2/0x2c10 [btrfs] btrfs_make_block_group+0x36b/0x870 [btrfs] btrfs_create_chunk+0x147d/0x2320 [btrfs] btrfs_chunk_alloc+0x2ce/0xcf0 [btrfs] start_transaction+0xce6/0x1620 [btrfs] btrfs_uuid_scan_kthread+0x4ee/0x5b0 [btrfs] kthread+0x39d/0x750 ret_from_fork+0x30/0x70 ret_from_fork_asm+0x1a/0x30 -> #2 (&fs_info->dev_replace.rwsem){++++}-{4:4}: down_read+0x9b/0x470 btrfs_map_block+0x2ce/0x2ce0 [btrfs] btrfs_submit_chunk+0x2d4/0x16c0 [btrfs] btrfs_submit_bbio+0x16/0x30 [btrfs] btree_write_cache_pages+0xb5a/0xf90 [btrfs] do_writepages+0x17f/0x7b0 __writeback_single_inode+0x114/0xb00 writeback_sb_inodes+0x52b/0xe00 wb_writeback+0x1a7/0x800 wb_workfn+0x12a/0xbd0 process_one_work+0x85a/0x1460 worker_thread+0x5e2/0xfc0 kthread+0x39d/0x750 ret_from_fork+0x30/0x70 ret_from_fork_asm+0x1a/0x30 -> #1 (&fs_info->zoned_meta_io_lock){+.+.}-{4:4}: __mutex_lock+0x1aa/0x1360 btree_write_cache_pages+0x252/0xf90 [btrfs] do_writepages+0x17f/0x7b0 __writeback_single_inode+0x114/0xb00 writeback_sb_inodes+0x52b/0xe00 wb_writeback+0x1a7/0x800 wb_workfn+0x12a/0xbd0 process_one_work+0x85a/0x1460 worker_thread+0x5e2/0xfc0 kthread+0x39d/0x750 ret_from_fork+0x30/0x70 ret_from_fork_asm+0x1a/0x30 -> #0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}: __lock_acquire+0x2f52/0x5ea0 lock_acquire+0x1b1/0x540 __flush_work+0x3ac/0xb60 wb_shutdown+0x15b/0x1f0 bdi_unregister+0x172/0x5b0 del_gendisk+0x841/0xa20 sd_remove+0x85/0x130 device_release_driver_internal+0x368/0x520 bus_remove_device+0x1f1/0x3f0 device_del+0x3bd/0x9c0 __scsi_remove_device+0x272/0x340 scsi_forget_host+0xf7/0x170 scsi_remove_host+0xd2/0x2a0 sdebug_driver_remove+0x52/0x2f0 [scsi_debug] device_release_driver_internal+0x368/0x520 bus_remove_device+0x1f1/0x3f0 device_del+0x3bd/0x9c0 device_unregister+0x13/0xa0 sdebug_do_remove_host+0x1fb/0x290 [scsi_debug] scsi_debug_exit+0x17/0x70 [scsi_debug] __do_sys_delete_module.isra.0+0x321/0x520 do_syscall_64+0x93/0x180 entry_SYSCALL_64_after_hwframe+0x76/0x7e other info that might help us debug this: Chain exists of: (work_completion)(&(&wb->dwork)->work) --> &fs_info->dev_replace.rwsem --> &q->q_usage_counter(queue)#16 Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&q->q_usage_counter(queue)#16); lock(&fs_info->dev_replace.rwsem); lock(&q->q_usage_counter(queue)#16); lock((work_completion)(&(&wb->dwork)->work)); *** DEADLOCK *** 5 locks held by modprobe/1110: #0: ffff88811f7bc108 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0x8f/0x520 #1: ffff8881022ee0e0 (&shost->scan_mutex){+.+.}-{4:4}, at: scsi_remove_host+0x20/0x2a0 #2: ffff88811b4c4378 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0x8f/0x520 #3: ffff8881205b6f20 (&q->q_usage_counter(queue)#16){++++}-{0:0}, at: sd_remove+0x85/0x130 #4: ffffffffa3284360 (rcu_read_lock){....}-{1:3}, at: __flush_work+0xda/0xb60 stack backtrace: CPU: 0 UID: 0 PID: 1110 Comm: modprobe Not tainted 6.14.0-rc1 #252 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-3.fc41 04/01/2014 Call Trace: <TASK> dump_stack_lvl+0x6a/0x90 print_circular_bug.cold+0x1e0/0x274 check_noncircular+0x306/0x3f0 ? __pfx_check_noncircular+0x10/0x10 ? mark_lock+0xf5/0x1650 ? __pfx_check_irq_usage+0x10/0x10 ? lockdep_lock+0xca/0x1c0 ? __pfx_lockdep_lock+0x10/0x10 __lock_acquire+0x2f52/0x5ea0 ? __pfx___lock_acquire+0x10/0x10 ? __pfx_mark_lock+0x10/0x10 lock_acquire+0x1b1/0x540 ? __flush_work+0x38f/0xb60 ? __pfx_lock_acquire+0x10/0x10 ? __pfx_lock_release+0x10/0x10 ? mark_held_locks+0x94/0xe0 ? __flush_work+0x38f/0xb60 __flush_work+0x3ac/0xb60 ? __flush_work+0x38f/0xb60 ? __pfx_mark_lock+0x10/0x10 ? __pfx___flush_work+0x10/0x10 ? __pfx_wq_barrier_func+0x10/0x10 ? __pfx___might_resched+0x10/0x10 ? mark_held_locks+0x94/0xe0 wb_shutdown+0x15b/0x1f0 bdi_unregister+0x172/0x5b0 ? __pfx_bdi_unregister+0x10/0x10 ? up_write+0x1ba/0x510 del_gendisk+0x841/0xa20 ? __pfx_del_gendisk+0x10/0x10 ? _raw_spin_unlock_irqrestore+0x35/0x60 ? __pm_runtime_resume+0x79/0x110 sd_remove+0x85/0x130 device_release_driver_internal+0x368/0x520 ? kobject_put+0x5d/0x4a0 bus_remove_device+0x1f1/0x3f0 device_del+0x3bd/0x9c0 ? __pfx_device_del+0x10/0x10 __scsi_remove_device+0x272/0x340 scsi_forget_host+0xf7/0x170 scsi_remove_host+0xd2/0x2a0 sdebug_driver_remove+0x52/0x2f0 [scsi_debug] ? kernfs_remove_by_name_ns+0xc0/0xf0 device_release_driver_internal+0x368/0x520 ? kobject_put+0x5d/0x4a0 bus_remove_device+0x1f1/0x3f0 device_del+0x3bd/0x9c0 ? __pfx_device_del+0x10/0x10 ? __pfx___mutex_unlock_slowpath+0x10/0x10 device_unregister+0x13/0xa0 sdebug_do_remove_host+0x1fb/0x290 [scsi_debug] scsi_debug_exit+0x17/0x70 [scsi_debug] __do_sys_delete_module.isra.0+0x321/0x520 ? __pfx___do_sys_delete_module.isra.0+0x10/0x10 ? __pfx_slab_free_after_rcu_debug+0x10/0x10 ? kasan_save_stack+0x2c/0x50 ? kasan_record_aux_stack+0xa3/0xb0 ? __call_rcu_common.constprop.0+0xc4/0xfb0 ? kmem_cache_free+0x3a0/0x590 ? __x64_sys_close+0x78/0xd0 do_syscall_64+0x93/0x180 ? lock_is_held_type+0xd5/0x130 ? __call_rcu_common.constprop.0+0x3c0/0xfb0 ? lockdep_hardirqs_on+0x78/0x100 ? __call_rcu_common.constprop.0+0x3c0/0xfb0 ? __pfx___call_rcu_common.constprop.0+0x10/0x10 ? kmem_cache_free+0x3a0/0x590 ? lockdep_hardirqs_on_prepare+0x16d/0x400 ? do_syscall_64+0x9f/0x180 ? lockdep_hardirqs_on+0x78/0x100 ? do_syscall_64+0x9f/0x180 ? __pfx___x64_sys_openat+0x10/0x10 ? lockdep_hardirqs_on_prepare+0x16d/0x400 ? do_syscall_64+0x9f/0x180 ? lockdep_hardirqs_on+0x78/0x100 ? do_syscall_64+0x9f/0x180 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x7f436712b68b RSP: 002b:00007ffe9f1a8658 EFLAGS: 00000206 ORIG_RAX: 00000000000000b0 RAX: ffffffffffffffda RBX: 00005559b367fd80 RCX: 00007f436712b68b RDX: 0000000000000000 RSI: 0000000000000800 RDI: 00005559b367fde8 RBP: 00007ffe9f1a8680 R08: 1999999999999999 R09: 0000000000000000 R10: 00007f43671a5fe0 R11: 0000000000000206 R12: 0000000000000000 R13: 00007ffe9f1a86b0 R14: 0000000000000000 R15: 0000000000000000 </TASK> Reported-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com> CC: <stable@vger.kernel.org> # 6.13+ Tested-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com> Reviewed-by: Damien Le Moal <dlemoal@kernel.org> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com> Signed-off-by: David Sterba <dsterba@suse.com>
shashim-quic
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May 16, 2025
[BUG] There is a bug report that a syzbot reproducer can lead to the following busy inode at unmount time: BTRFS info (device loop1): last unmount of filesystem 1680000e-3c1e-4c46-84b6-56bd3909af50 VFS: Busy inodes after unmount of loop1 (btrfs) ------------[ cut here ]------------ kernel BUG at fs/super.c:650! Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI CPU: 0 UID: 0 PID: 48168 Comm: syz-executor Not tainted 6.15.0-rc2-00471-g119009db2674 #2 PREEMPT(full) Hardware name: QEMU Ubuntu 24.04 PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 RIP: 0010:generic_shutdown_super+0x2e9/0x390 fs/super.c:650 Call Trace: <TASK> kill_anon_super+0x3a/0x60 fs/super.c:1237 btrfs_kill_super+0x3b/0x50 fs/btrfs/super.c:2099 deactivate_locked_super+0xbe/0x1a0 fs/super.c:473 deactivate_super fs/super.c:506 [inline] deactivate_super+0xe2/0x100 fs/super.c:502 cleanup_mnt+0x21f/0x440 fs/namespace.c:1435 task_work_run+0x14d/0x240 kernel/task_work.c:227 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop kernel/entry/common.c:114 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x269/0x290 kernel/entry/common.c:218 do_syscall_64+0xd4/0x250 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f </TASK> [CAUSE] When btrfs_alloc_path() failed, btrfs_iget() directly returned without releasing the inode already allocated by btrfs_iget_locked(). This results the above busy inode and trigger the kernel BUG. [FIX] Fix it by calling iget_failed() if btrfs_alloc_path() failed. If we hit error inside btrfs_read_locked_inode(), it will properly call iget_failed(), so nothing to worry about. Although the iget_failed() cleanup inside btrfs_read_locked_inode() is a break of the normal error handling scheme, let's fix the obvious bug and backport first, then rework the error handling later. Reported-by: Penglei Jiang <superman.xpt@gmail.com> Link: https://lore.kernel.org/linux-btrfs/20250421102425.44431-1-superman.xpt@gmail.com/ Fixes: 7c855e1 ("btrfs: remove conditional path allocation in btrfs_read_locked_inode()") CC: stable@vger.kernel.org # 6.13+ Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Penglei Jiang <superman.xpt@gmail.com> Signed-off-by: David Sterba <dsterba@suse.com>
shashim-quic
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…ux/kernel/git/kvmarm/kvmarm into HEAD KVM/arm64 fixes for 6.15, round #2 - Single fix for broken usage of 'multi-MIDR' infrastructure in PI code, adding an open-coded erratum check for everyone's favorite pile of sand: Cavium ThunderX
shashim-quic
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May 19, 2025
…unload
Kernel panic occurs when a devmem TCP socket is closed after NIC module
is unloaded.
This is Devmem TCP unregistration scenarios. number is an order.
(a)netlink socket close (b)pp destroy (c)uninstall result
1 2 3 OK
1 3 2 (d)Impossible
2 1 3 OK
3 1 2 (e)Kernel panic
2 3 1 (d)Impossible
3 2 1 (d)Impossible
(a) netdev_nl_sock_priv_destroy() is called when devmem TCP socket is
closed.
(b) page_pool_destroy() is called when the interface is down.
(c) mp_ops->uninstall() is called when an interface is unregistered.
(d) There is no scenario in mp_ops->uninstall() is called before
page_pool_destroy().
Because unregister_netdevice_many_notify() closes interfaces first
and then calls mp_ops->uninstall().
(e) netdev_nl_sock_priv_destroy() accesses struct net_device to acquire
netdev_lock().
But if the interface module has already been removed, net_device
pointer is invalid, so it causes kernel panic.
In summary, there are only 3 possible scenarios.
A. sk close -> pp destroy -> uninstall.
B. pp destroy -> sk close -> uninstall.
C. pp destroy -> uninstall -> sk close.
Case C is a kernel panic scenario.
In order to fix this problem, It makes mp_dmabuf_devmem_uninstall() set
binding->dev to NULL.
It indicates an bound net_device was unregistered.
It makes netdev_nl_sock_priv_destroy() do not acquire netdev_lock()
if binding->dev is NULL.
A new binding->lock is added to protect a dev of a binding.
So, lock ordering is like below.
priv->lock
netdev_lock(dev)
binding->lock
Tests:
Scenario A:
./ncdevmem -s 192.168.1.4 -c 192.168.1.2 -f $interface -l -p 8000 \
-v 7 -t 1 -q 1 &
pid=$!
sleep 10
kill $pid
ip link set $interface down
modprobe -rv $module
Scenario B:
./ncdevmem -s 192.168.1.4 -c 192.168.1.2 -f $interface -l -p 8000 \
-v 7 -t 1 -q 1 &
pid=$!
sleep 10
ip link set $interface down
kill $pid
modprobe -rv $module
Scenario C:
./ncdevmem -s 192.168.1.4 -c 192.168.1.2 -f $interface -l -p 8000 \
-v 7 -t 1 -q 1 &
pid=$!
sleep 10
modprobe -rv $module
sleep 5
kill $pid
Splat looks like:
Oops: general protection fault, probably for non-canonical address 0xdffffc001fffa9f7: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN NOPTI
KASAN: probably user-memory-access in range [0x00000000fffd4fb8-0x00000000fffd4fbf]
CPU: 0 UID: 0 PID: 2041 Comm: ncdevmem Tainted: G B W 6.15.0-rc1+ #2 PREEMPT(undef) 0947ec89efa0fd68838b78e36aa1617e97ff5d7f
Tainted: [B]=BAD_PAGE, [W]=WARN
RIP: 0010:__mutex_lock (./include/linux/sched.h:2244 kernel/locking/mutex.c:400 kernel/locking/mutex.c:443 kernel/locking/mutex.c:605 kernel/locking/mutex.c:746)
Code: ea 03 80 3c 02 00 0f 85 4f 13 00 00 49 8b 1e 48 83 e3 f8 74 6a 48 b8 00 00 00 00 00 fc ff df 48 8d 7b 34 48 89 fa 48 c1 ea 03 <0f> b6 f
RSP: 0018:ffff88826f7ef730 EFLAGS: 00010203
RAX: dffffc0000000000 RBX: 00000000fffd4f88 RCX: ffffffffaa9bc811
RDX: 000000001fffa9f7 RSI: 0000000000000008 RDI: 00000000fffd4fbc
RBP: ffff88826f7ef8b0 R08: 0000000000000000 R09: ffffed103e6aa1a4
R10: 0000000000000007 R11: ffff88826f7ef442 R12: fffffbfff669f65e
R13: ffff88812a830040 R14: ffff8881f3550d20 R15: 00000000fffd4f88
FS: 0000000000000000(0000) GS:ffff888866c05000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000563bed0cb288 CR3: 00000001a7c98000 CR4: 00000000007506f0
PKRU: 55555554
Call Trace:
<TASK>
...
netdev_nl_sock_priv_destroy (net/core/netdev-genl.c:953 (discriminator 3))
genl_release (net/netlink/genetlink.c:653 net/netlink/genetlink.c:694 net/netlink/genetlink.c:705)
...
netlink_release (net/netlink/af_netlink.c:737)
...
__sock_release (net/socket.c:647)
sock_close (net/socket.c:1393)
Fixes: 1d22d30 ("net: drop rtnl_lock for queue_mgmt operations")
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Link: https://patch.msgid.link/20250514154028.1062909-1-ap420073@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
shashim-quic
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Jun 10, 2025
Add a compile-time check that `*$ptr` is of the type of `$type->$($f)*`. Rename those placeholders for clarity. Given the incorrect usage: > diff --git a/rust/kernel/rbtree.rs b/rust/kernel/rbtree.rs > index 8d978c8..6a7089149878 100644 > --- a/rust/kernel/rbtree.rs > +++ b/rust/kernel/rbtree.rs > @@ -329,7 +329,7 @@ fn raw_entry(&mut self, key: &K) -> RawEntry<'_, K, V> { > while !(*child_field_of_parent).is_null() { > let curr = *child_field_of_parent; > // SAFETY: All links fields we create are in a `Node<K, V>`. > - let node = unsafe { container_of!(curr, Node<K, V>, links) }; > + let node = unsafe { container_of!(curr, Node<K, V>, key) }; > > // SAFETY: `node` is a non-null node so it is valid by the type invariants. > match key.cmp(unsafe { &(*node).key }) { this patch produces the compilation error: > error[E0308]: mismatched types > --> rust/kernel/lib.rs:220:45 > | > 220 | $crate::assert_same_type(field_ptr, (&raw const (*container_ptr).$($fields)*).cast_mut()); > | ------------------------ --------- ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ expected `*mut rb_node`, found `*mut K` > | | | > | | expected all arguments to be this `*mut bindings::rb_node` type because they need to match the type of this parameter > | arguments to this function are incorrect > | > ::: rust/kernel/rbtree.rs:270:6 > | > 270 | impl<K, V> RBTree<K, V> > | - found this type parameter > ... > 332 | let node = unsafe { container_of!(curr, Node<K, V>, key) }; > | ------------------------------------ in this macro invocation > | > = note: expected raw pointer `*mut bindings::rb_node` > found raw pointer `*mut K` > note: function defined here > --> rust/kernel/lib.rs:227:8 > | > 227 | pub fn assert_same_type<T>(_: T, _: T) {} > | ^^^^^^^^^^^^^^^^ - ---- ---- this parameter needs to match the `*mut bindings::rb_node` type of parameter #1 > | | | > | | parameter #2 needs to match the `*mut bindings::rb_node` type of this parameter > | parameter #1 and parameter #2 both reference this parameter `T` > = note: this error originates in the macro `container_of` (in Nightly builds, run with -Z macro-backtrace for more info) [ We decided to go with a variation of v1 [1] that became v4, since it seems like the obvious approach, the error messages seem good enough and the debug performance should be fine, given the kernel is always built with -O2. In the future, we may want to make the helper non-hidden, with proper documentation, for others to use. [1] https://lore.kernel.org/rust-for-linux/CANiq72kQWNfSV0KK6qs6oJt+aGdgY=hXg=wJcmK3zYcokY1LNw@mail.gmail.com/ - Miguel ] Suggested-by: Alice Ryhl <aliceryhl@google.com> Link: https://lore.kernel.org/all/CAH5fLgh6gmqGBhPMi2SKn7mCmMWfOSiS0WP5wBuGPYh9ZTAiww@mail.gmail.com/ Signed-off-by: Tamir Duberstein <tamird@gmail.com> Reviewed-by: Benno Lossin <lossin@kernel.org> Link: https://lore.kernel.org/r/20250529-b4-container-of-type-check-v4-1-bf3a7ad73cec@gmail.com [ Added intra-doc link. - Miguel ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Komal-Bajaj
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Jun 18, 2025
…/kernel/git/kvmarm/kvmarm into HEAD KVM/arm64 fixes for 6.16, take #2 - Rework of system register accessors for system registers that are directly writen to memory, so that sanitisation of the in-memory value happens at the correct time (after the read, or before the write). For convenience, RMW-style accessors are also provided. - Multiple fixes for the so-called "arch-timer-edge-cases' selftest, which was always broken.
Komal-Bajaj
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Jun 23, 2025
As-per the SBI specification, an SBI remote fence operation applies to the entire address space if either: 1) start_addr and size are both 0 2) size is equal to 2^XLEN-1 >From the above, only #1 is checked by SBI SFENCE calls so fix the size parameter check in SBI SFENCE calls to cover #2 as well. Fixes: 13acfec ("RISC-V: KVM: Add remote HFENCE functions based on VCPU requests") Reviewed-by: Atish Patra <atishp@rivosinc.com> Signed-off-by: Anup Patel <apatel@ventanamicro.com> Link: https://lore.kernel.org/r/20250605061458.196003-2-apatel@ventanamicro.com Signed-off-by: Anup Patel <anup@brainfault.org>
Komal-Bajaj
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Jun 23, 2025
This patch fixes an issue seen in a large-scale deployment under heavy
incoming pkts where the aRFS flow wrongly matches a flow and reprograms the
NIC with wrong settings. That mis-steering causes RX-path latency spikes
and noisy neighbor effects when many connections collide on the same
hash (some of our production servers have 20-30K connections).
set_rps_cpu() calls ndo_rx_flow_steer() with flow_id that is calculated by
hashing the skb sized by the per rx-queue table size. This results in
multiple connections (even across different rx-queues) getting the same
hash value. The driver steer function modifies the wrong flow to use this
rx-queue, e.g.: Flow#1 is first added:
Flow#1: <ip1, port1, ip2, port2>, Hash 'h', q#10
Later when a new flow needs to be added:
Flow#2: <ip3, port3, ip4, port4>, Hash 'h', q#20
The driver finds the hash 'h' from Flow#1 and updates it to use q#20. This
results in both flows getting un-optimized - packets for Flow#1 goes to
q#20, and then reprogrammed back to q#10 later and so on; and Flow #2
programming is never done as Flow#1 is matched first for all misses. Many
flows may wrongly share the same hash and reprogram rules of the original
flow each with their own q#.
Tested on two 144-core servers with 16K netperf sessions for 180s. Netperf
clients are pinned to cores 0-71 sequentially (so that wrong packets on q#s
72-143 can be measured). IRQs are set 1:1 for queues -> CPUs, enable XPS,
enable aRFS (global value is 144 * rps_flow_cnt).
Test notes about results from ice_rx_flow_steer():
---------------------------------------------------
1. "Skip:" counter increments here:
if (fltr_info->q_index == rxq_idx ||
arfs_entry->fltr_state != ICE_ARFS_ACTIVE)
goto out;
2. "Add:" counter increments here:
ret = arfs_entry->fltr_info.fltr_id;
INIT_HLIST_NODE(&arfs_entry->list_entry);
3. "Update:" counter increments here:
/* update the queue to forward to on an already existing flow */
Runtime comparison: original code vs with the patch for different
rps_flow_cnt values.
+-------------------------------+--------------+--------------+
| rps_flow_cnt | 512 | 2048 |
+-------------------------------+--------------+--------------+
| Ratio of Pkts on Good:Bad q's | 214 vs 822K | 1.1M vs 980K |
| Avoid wrong aRFS programming | 0 vs 310K | 0 vs 30K |
| CPU User | 216 vs 183 | 216 vs 206 |
| CPU System | 1441 vs 1171 | 1447 vs 1320 |
| CPU Softirq | 1245 vs 920 | 1238 vs 961 |
| CPU Total | 29 vs 22.7 | 29 vs 24.9 |
| aRFS Update | 533K vs 59 | 521K vs 32 |
| aRFS Skip | 82M vs 77M | 7.2M vs 4.5M |
+-------------------------------+--------------+--------------+
A separate TCP_STREAM and TCP_RR with 1,4,8,16,64,128,256,512 connections
showed no performance degradation.
Some points on the patch/aRFS behavior:
1. Enabling full tuple matching ensures flows are always correctly matched,
even with smaller hash sizes.
2. 5-6% drop in CPU utilization as the packets arrive at the correct CPUs
and fewer calls to driver for programming on misses.
3. Larger hash tables reduces mis-steering due to more unique flow hashes,
but still has clashes. However, with larger per-device rps_flow_cnt, old
flows take more time to expire and new aRFS flows cannot be added if h/w
limits are reached (rps_may_expire_flow() succeeds when 10*rps_flow_cnt
pkts have been processed by this cpu that are not part of the flow).
Fixes: 28bf267 ("ice: Implement aRFS")
Signed-off-by: Krishna Kumar <krikku@gmail.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Tested-by: Rinitha S <sx.rinitha@intel.com> (A Contingent worker at Intel)
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
Komal-Bajaj
pushed a commit
that referenced
this pull request
Jun 23, 2025
syzkaller reported a null-ptr-deref in sock_omalloc() while allocating a CALIPSO option. [0] The NULL is of struct sock, which was fetched by sk_to_full_sk() in calipso_req_setattr(). Since commit a1a5344 ("tcp: avoid two atomic ops for syncookies"), reqsk->rsk_listener could be NULL when SYN Cookie is returned to its client, as hinted by the leading SYN Cookie log. Here are 3 options to fix the bug: 1) Return 0 in calipso_req_setattr() 2) Return an error in calipso_req_setattr() 3) Alaways set rsk_listener 1) is no go as it bypasses LSM, but 2) effectively disables SYN Cookie for CALIPSO. 3) is also no go as there have been many efforts to reduce atomic ops and make TCP robust against DDoS. See also commit 3b24d85 ("tcp/dccp: do not touch listener sk_refcnt under synflood"). As of the blamed commit, SYN Cookie already did not need refcounting, and no one has stumbled on the bug for 9 years, so no CALIPSO user will care about SYN Cookie. Let's return an error in calipso_req_setattr() and calipso_req_delattr() in the SYN Cookie case. This can be reproduced by [1] on Fedora and now connect() of nc times out. [0]: TCP: request_sock_TCPv6: Possible SYN flooding on port [::]:20002. Sending cookies. Oops: general protection fault, probably for non-canonical address 0xdffffc0000000006: 0000 [#1] PREEMPT SMP KASAN NOPTI KASAN: null-ptr-deref in range [0x0000000000000030-0x0000000000000037] CPU: 3 UID: 0 PID: 12262 Comm: syz.1.2611 Not tainted 6.14.0 #2 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014 RIP: 0010:read_pnet include/net/net_namespace.h:406 [inline] RIP: 0010:sock_net include/net/sock.h:655 [inline] RIP: 0010:sock_kmalloc+0x35/0x170 net/core/sock.c:2806 Code: 89 d5 41 54 55 89 f5 53 48 89 fb e8 25 e3 c6 fd e8 f0 91 e3 00 48 8d 7b 30 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 26 01 00 00 48 b8 00 00 00 00 00 fc ff df 4c 8b RSP: 0018:ffff88811af89038 EFLAGS: 00010216 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffff888105266400 RDX: 0000000000000006 RSI: ffff88800c890000 RDI: 0000000000000030 RBP: 0000000000000050 R08: 0000000000000000 R09: ffff88810526640e R10: ffffed1020a4cc81 R11: ffff88810526640f R12: 0000000000000000 R13: 0000000000000820 R14: ffff888105266400 R15: 0000000000000050 FS: 00007f0653a07640(0000) GS:ffff88811af80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f863ba096f4 CR3: 00000000163c0005 CR4: 0000000000770ef0 PKRU: 80000000 Call Trace: <IRQ> ipv6_renew_options+0x279/0x950 net/ipv6/exthdrs.c:1288 calipso_req_setattr+0x181/0x340 net/ipv6/calipso.c:1204 calipso_req_setattr+0x56/0x80 net/netlabel/netlabel_calipso.c:597 netlbl_req_setattr+0x18a/0x440 net/netlabel/netlabel_kapi.c:1249 selinux_netlbl_inet_conn_request+0x1fb/0x320 security/selinux/netlabel.c:342 selinux_inet_conn_request+0x1eb/0x2c0 security/selinux/hooks.c:5551 security_inet_conn_request+0x50/0xa0 security/security.c:4945 tcp_v6_route_req+0x22c/0x550 net/ipv6/tcp_ipv6.c:825 tcp_conn_request+0xec8/0x2b70 net/ipv4/tcp_input.c:7275 tcp_v6_conn_request+0x1e3/0x440 net/ipv6/tcp_ipv6.c:1328 tcp_rcv_state_process+0xafa/0x52b0 net/ipv4/tcp_input.c:6781 tcp_v6_do_rcv+0x8a6/0x1a40 net/ipv6/tcp_ipv6.c:1667 tcp_v6_rcv+0x505e/0x5b50 net/ipv6/tcp_ipv6.c:1904 ip6_protocol_deliver_rcu+0x17c/0x1da0 net/ipv6/ip6_input.c:436 ip6_input_finish+0x103/0x180 net/ipv6/ip6_input.c:480 NF_HOOK include/linux/netfilter.h:314 [inline] NF_HOOK include/linux/netfilter.h:308 [inline] ip6_input+0x13c/0x6b0 net/ipv6/ip6_input.c:491 dst_input include/net/dst.h:469 [inline] ip6_rcv_finish net/ipv6/ip6_input.c:79 [inline] ip6_rcv_finish+0xb6/0x490 net/ipv6/ip6_input.c:69 NF_HOOK include/linux/netfilter.h:314 [inline] NF_HOOK include/linux/netfilter.h:308 [inline] ipv6_rcv+0xf9/0x490 net/ipv6/ip6_input.c:309 __netif_receive_skb_one_core+0x12e/0x1f0 net/core/dev.c:5896 __netif_receive_skb+0x1d/0x170 net/core/dev.c:6009 process_backlog+0x41e/0x13b0 net/core/dev.c:6357 __napi_poll+0xbd/0x710 net/core/dev.c:7191 napi_poll net/core/dev.c:7260 [inline] net_rx_action+0x9de/0xde0 net/core/dev.c:7382 handle_softirqs+0x19a/0x770 kernel/softirq.c:561 do_softirq.part.0+0x36/0x70 kernel/softirq.c:462 </IRQ> <TASK> do_softirq arch/x86/include/asm/preempt.h:26 [inline] __local_bh_enable_ip+0xf1/0x110 kernel/softirq.c:389 local_bh_enable include/linux/bottom_half.h:33 [inline] rcu_read_unlock_bh include/linux/rcupdate.h:919 [inline] __dev_queue_xmit+0xc2a/0x3c40 net/core/dev.c:4679 dev_queue_xmit include/linux/netdevice.h:3313 [inline] neigh_hh_output include/net/neighbour.h:523 [inline] neigh_output include/net/neighbour.h:537 [inline] ip6_finish_output2+0xd69/0x1f80 net/ipv6/ip6_output.c:141 __ip6_finish_output net/ipv6/ip6_output.c:215 [inline] ip6_finish_output+0x5dc/0xd60 net/ipv6/ip6_output.c:226 NF_HOOK_COND include/linux/netfilter.h:303 [inline] ip6_output+0x24b/0x8d0 net/ipv6/ip6_output.c:247 dst_output include/net/dst.h:459 [inline] NF_HOOK include/linux/netfilter.h:314 [inline] NF_HOOK include/linux/netfilter.h:308 [inline] ip6_xmit+0xbbc/0x20d0 net/ipv6/ip6_output.c:366 inet6_csk_xmit+0x39a/0x720 net/ipv6/inet6_connection_sock.c:135 __tcp_transmit_skb+0x1a7b/0x3b40 net/ipv4/tcp_output.c:1471 tcp_transmit_skb net/ipv4/tcp_output.c:1489 [inline] tcp_send_syn_data net/ipv4/tcp_output.c:4059 [inline] tcp_connect+0x1c0c/0x4510 net/ipv4/tcp_output.c:4148 tcp_v6_connect+0x156c/0x2080 net/ipv6/tcp_ipv6.c:333 __inet_stream_connect+0x3a7/0xed0 net/ipv4/af_inet.c:677 tcp_sendmsg_fastopen+0x3e2/0x710 net/ipv4/tcp.c:1039 tcp_sendmsg_locked+0x1e82/0x3570 net/ipv4/tcp.c:1091 tcp_sendmsg+0x2f/0x50 net/ipv4/tcp.c:1358 inet6_sendmsg+0xb9/0x150 net/ipv6/af_inet6.c:659 sock_sendmsg_nosec net/socket.c:718 [inline] __sock_sendmsg+0xf4/0x2a0 net/socket.c:733 __sys_sendto+0x29a/0x390 net/socket.c:2187 __do_sys_sendto net/socket.c:2194 [inline] __se_sys_sendto net/socket.c:2190 [inline] __x64_sys_sendto+0xe1/0x1c0 net/socket.c:2190 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xc3/0x1d0 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f06553c47ed Code: 02 b8 ff ff ff ff c3 66 0f 1f 44 00 00 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f0653a06fc8 EFLAGS: 00000246 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 00007f0655605fa0 RCX: 00007f06553c47ed RDX: 0000000000000000 RSI: 0000000000000000 RDI: 000000000000000b RBP: 00007f065545db38 R08: 0000200000000140 R09: 000000000000001c R10: f7384d4ea84b01bd R11: 0000000000000246 R12: 0000000000000000 R13: 00007f0655605fac R14: 00007f0655606038 R15: 00007f06539e7000 </TASK> Modules linked in: [1]: dnf install -y selinux-policy-targeted policycoreutils netlabel_tools procps-ng nmap-ncat mount -t selinuxfs none /sys/fs/selinux load_policy netlabelctl calipso add pass doi:1 netlabelctl map del default netlabelctl map add default address:::1 protocol:calipso,1 sysctl net.ipv4.tcp_syncookies=2 nc -l ::1 80 & nc ::1 80 Fixes: e1adea9 ("calipso: Allow request sockets to be relabelled by the lsm.") Reported-by: syzkaller <syzkaller@googlegroups.com> Reported-by: John Cheung <john.cs.hey@gmail.com> Closes: https://lore.kernel.org/netdev/CAP=Rh=MvfhrGADy+-WJiftV2_WzMH4VEhEFmeT28qY+4yxNu4w@mail.gmail.com/ Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Acked-by: Paul Moore <paul@paul-moore.com> Link: https://patch.msgid.link/20250617224125.17299-1-kuni1840@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Komal-Bajaj
pushed a commit
that referenced
this pull request
Jul 1, 2025
The WARN_ON_ONCE is introduced on truncate_folio_batch_exceptionals() to capture whether the filesystem has removed all DAX entries or not. And the fix has been applied on the filesystem xfs and ext4 by the commit 0e2f80a ("fs/dax: ensure all pages are idle prior to filesystem unmount"). Apply the missed fix on filesystem fuse to fix the runtime warning: [ 2.011450] ------------[ cut here ]------------ [ 2.011873] WARNING: CPU: 0 PID: 145 at mm/truncate.c:89 truncate_folio_batch_exceptionals+0x272/0x2b0 [ 2.012468] Modules linked in: [ 2.012718] CPU: 0 UID: 1000 PID: 145 Comm: weston Not tainted 6.16.0-rc2-WSL2-STABLE #2 PREEMPT(undef) [ 2.013292] RIP: 0010:truncate_folio_batch_exceptionals+0x272/0x2b0 [ 2.013704] Code: 48 63 d0 41 29 c5 48 8d 1c d5 00 00 00 00 4e 8d 6c 2a 01 49 c1 e5 03 eb 09 48 83 c3 08 49 39 dd 74 83 41 f6 44 1c 08 01 74 ef <0f> 0b 49 8b 34 1e 48 89 ef e8 10 a2 17 00 eb df 48 8b 7d 00 e8 35 [ 2.014845] RSP: 0018:ffffa47ec33f3b10 EFLAGS: 00010202 [ 2.015279] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 [ 2.015884] RDX: 0000000000000000 RSI: ffffa47ec33f3ca0 RDI: ffff98aa44f3fa80 [ 2.016377] RBP: ffff98aa44f3fbf0 R08: ffffa47ec33f3ba8 R09: 0000000000000000 [ 2.016942] R10: 0000000000000001 R11: 0000000000000000 R12: ffffa47ec33f3ca0 [ 2.017437] R13: 0000000000000008 R14: ffffa47ec33f3ba8 R15: 0000000000000000 [ 2.017972] FS: 000079ce006afa40(0000) GS:ffff98aade441000(0000) knlGS:0000000000000000 [ 2.018510] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 2.018987] CR2: 000079ce03e74000 CR3: 000000010784f006 CR4: 0000000000372eb0 [ 2.019518] Call Trace: [ 2.019729] <TASK> [ 2.019901] truncate_inode_pages_range+0xd8/0x400 [ 2.020280] ? timerqueue_add+0x66/0xb0 [ 2.020574] ? get_nohz_timer_target+0x2a/0x140 [ 2.020904] ? timerqueue_add+0x66/0xb0 [ 2.021231] ? timerqueue_del+0x2e/0x50 [ 2.021646] ? __remove_hrtimer+0x39/0x90 [ 2.022017] ? srso_alias_untrain_ret+0x1/0x10 [ 2.022497] ? psi_group_change+0x136/0x350 [ 2.023046] ? _raw_spin_unlock+0xe/0x30 [ 2.023514] ? finish_task_switch.isra.0+0x8d/0x280 [ 2.024068] ? __schedule+0x532/0xbd0 [ 2.024551] fuse_evict_inode+0x29/0x190 [ 2.025131] evict+0x100/0x270 [ 2.025641] ? _atomic_dec_and_lock+0x39/0x50 [ 2.026316] ? __pfx_generic_delete_inode+0x10/0x10 [ 2.026843] __dentry_kill+0x71/0x180 [ 2.027335] dput+0xeb/0x1b0 [ 2.027725] __fput+0x136/0x2b0 [ 2.028054] __x64_sys_close+0x3d/0x80 [ 2.028469] do_syscall_64+0x6d/0x1b0 [ 2.028832] ? clear_bhb_loop+0x30/0x80 [ 2.029182] ? clear_bhb_loop+0x30/0x80 [ 2.029533] ? clear_bhb_loop+0x30/0x80 [ 2.029902] entry_SYSCALL_64_after_hwframe+0x76/0x7e [ 2.030423] RIP: 0033:0x79ce03d0d067 [ 2.030820] Code: b8 ff ff ff ff e9 3e ff ff ff 66 0f 1f 84 00 00 00 00 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 b8 03 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 41 c3 48 83 ec 18 89 7c 24 0c e8 c3 a7 f8 ff [ 2.032354] RSP: 002b:00007ffef0498948 EFLAGS: 00000246 ORIG_RAX: 0000000000000003 [ 2.032939] RAX: ffffffffffffffda RBX: 00007ffef0498960 RCX: 000079ce03d0d067 [ 2.033612] RDX: 0000000000000003 RSI: 0000000000001000 RDI: 000000000000000d [ 2.034289] RBP: 00007ffef0498a30 R08: 000000000000000d R09: 0000000000000000 [ 2.034944] R10: 00007ffef0498978 R11: 0000000000000246 R12: 0000000000000001 [ 2.035610] R13: 00007ffef0498960 R14: 000079ce03e09ce0 R15: 0000000000000003 [ 2.036301] </TASK> [ 2.036532] ---[ end trace 0000000000000000 ]--- Link: https://lkml.kernel.org/r/20250621171507.3770-1-haiyuewa@163.com Fixes: bde708f ("fs/dax: always remove DAX page-cache entries when breaking layouts") Signed-off-by: Haiyue Wang <haiyuewa@163.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Miklos Szeredi <miklos@szeredi.hu> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Komal-Bajaj
pushed a commit
that referenced
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Jul 1, 2025
Fix cifs_signal_cifsd_for_reconnect() to take the correct lock order
and prevent the following deadlock from happening
======================================================
WARNING: possible circular locking dependency detected
6.16.0-rc3-build2+ #1301 Tainted: G S W
------------------------------------------------------
cifsd/6055 is trying to acquire lock:
ffff88810ad56038 (&tcp_ses->srv_lock){+.+.}-{3:3}, at: cifs_signal_cifsd_for_reconnect+0x134/0x200
but task is already holding lock:
ffff888119c64330 (&ret_buf->chan_lock){+.+.}-{3:3}, at: cifs_signal_cifsd_for_reconnect+0xcf/0x200
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #2 (&ret_buf->chan_lock){+.+.}-{3:3}:
validate_chain+0x1cf/0x270
__lock_acquire+0x60e/0x780
lock_acquire.part.0+0xb4/0x1f0
_raw_spin_lock+0x2f/0x40
cifs_setup_session+0x81/0x4b0
cifs_get_smb_ses+0x771/0x900
cifs_mount_get_session+0x7e/0x170
cifs_mount+0x92/0x2d0
cifs_smb3_do_mount+0x161/0x460
smb3_get_tree+0x55/0x90
vfs_get_tree+0x46/0x180
do_new_mount+0x1b0/0x2e0
path_mount+0x6ee/0x740
do_mount+0x98/0xe0
__do_sys_mount+0x148/0x180
do_syscall_64+0xa4/0x260
entry_SYSCALL_64_after_hwframe+0x76/0x7e
-> #1 (&ret_buf->ses_lock){+.+.}-{3:3}:
validate_chain+0x1cf/0x270
__lock_acquire+0x60e/0x780
lock_acquire.part.0+0xb4/0x1f0
_raw_spin_lock+0x2f/0x40
cifs_match_super+0x101/0x320
sget+0xab/0x270
cifs_smb3_do_mount+0x1e0/0x460
smb3_get_tree+0x55/0x90
vfs_get_tree+0x46/0x180
do_new_mount+0x1b0/0x2e0
path_mount+0x6ee/0x740
do_mount+0x98/0xe0
__do_sys_mount+0x148/0x180
do_syscall_64+0xa4/0x260
entry_SYSCALL_64_after_hwframe+0x76/0x7e
-> #0 (&tcp_ses->srv_lock){+.+.}-{3:3}:
check_noncircular+0x95/0xc0
check_prev_add+0x115/0x2f0
validate_chain+0x1cf/0x270
__lock_acquire+0x60e/0x780
lock_acquire.part.0+0xb4/0x1f0
_raw_spin_lock+0x2f/0x40
cifs_signal_cifsd_for_reconnect+0x134/0x200
__cifs_reconnect+0x8f/0x500
cifs_handle_standard+0x112/0x280
cifs_demultiplex_thread+0x64d/0xbc0
kthread+0x2f7/0x310
ret_from_fork+0x2a/0x230
ret_from_fork_asm+0x1a/0x30
other info that might help us debug this:
Chain exists of:
&tcp_ses->srv_lock --> &ret_buf->ses_lock --> &ret_buf->chan_lock
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&ret_buf->chan_lock);
lock(&ret_buf->ses_lock);
lock(&ret_buf->chan_lock);
lock(&tcp_ses->srv_lock);
*** DEADLOCK ***
3 locks held by cifsd/6055:
#0: ffffffff857de398 (&cifs_tcp_ses_lock){+.+.}-{3:3}, at: cifs_signal_cifsd_for_reconnect+0x7b/0x200
#1: ffff888119c64060 (&ret_buf->ses_lock){+.+.}-{3:3}, at: cifs_signal_cifsd_for_reconnect+0x9c/0x200
#2: ffff888119c64330 (&ret_buf->chan_lock){+.+.}-{3:3}, at: cifs_signal_cifsd_for_reconnect+0xcf/0x200
Cc: linux-cifs@vger.kernel.org
Reported-by: David Howells <dhowells@redhat.com>
Fixes: d7d7a66 ("cifs: avoid use of global locks for high contention data")
Reviewed-by: David Howells <dhowells@redhat.com>
Tested-by: David Howells <dhowells@redhat.com>
Signed-off-by: Paulo Alcantara (Red Hat) <pc@manguebit.org>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
sgaud-quic
pushed a commit
that referenced
this pull request
Jul 7, 2025
The issue arises when kzalloc() is invoked while holding umem_mutex or
any other lock acquired under umem_mutex. This is problematic because
kzalloc() can trigger fs_reclaim_aqcuire(), which may, in turn, invoke
mmu_notifier_invalidate_range_start(). This function can lead to
mlx5_ib_invalidate_range(), which attempts to acquire umem_mutex again,
resulting in a deadlock.
The problematic flow:
CPU0 | CPU1
---------------------------------------|------------------------------------------------
mlx5_ib_dereg_mr() |
→ revoke_mr() |
→ mutex_lock(&umem_odp->umem_mutex) |
| mlx5_mkey_cache_init()
| → mutex_lock(&dev->cache.rb_lock)
| → mlx5r_cache_create_ent_locked()
| → kzalloc(GFP_KERNEL)
| → fs_reclaim()
| → mmu_notifier_invalidate_range_start()
| → mlx5_ib_invalidate_range()
| → mutex_lock(&umem_odp->umem_mutex)
→ cache_ent_find_and_store() |
→ mutex_lock(&dev->cache.rb_lock) |
Additionally, when kzalloc() is called from within
cache_ent_find_and_store(), we encounter the same deadlock due to
re-acquisition of umem_mutex.
Solve by releasing umem_mutex in dereg_mr() after umr_revoke_mr()
and before acquiring rb_lock. This ensures that we don't hold
umem_mutex while performing memory allocations that could trigger
the reclaim path.
This change prevents the deadlock by ensuring proper lock ordering and
avoiding holding locks during memory allocation operations that could
trigger the reclaim path.
The following lockdep warning demonstrates the deadlock:
python3/20557 is trying to acquire lock:
ffff888387542128 (&umem_odp->umem_mutex){+.+.}-{4:4}, at:
mlx5_ib_invalidate_range+0x5b/0x550 [mlx5_ib]
but task is already holding lock:
ffffffff82f6b840 (mmu_notifier_invalidate_range_start){+.+.}-{0:0}, at:
unmap_vmas+0x7b/0x1a0
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #3 (mmu_notifier_invalidate_range_start){+.+.}-{0:0}:
fs_reclaim_acquire+0x60/0xd0
mem_cgroup_css_alloc+0x6f/0x9b0
cgroup_init_subsys+0xa4/0x240
cgroup_init+0x1c8/0x510
start_kernel+0x747/0x760
x86_64_start_reservations+0x25/0x30
x86_64_start_kernel+0x73/0x80
common_startup_64+0x129/0x138
-> #2 (fs_reclaim){+.+.}-{0:0}:
fs_reclaim_acquire+0x91/0xd0
__kmalloc_cache_noprof+0x4d/0x4c0
mlx5r_cache_create_ent_locked+0x75/0x620 [mlx5_ib]
mlx5_mkey_cache_init+0x186/0x360 [mlx5_ib]
mlx5_ib_stage_post_ib_reg_umr_init+0x3c/0x60 [mlx5_ib]
__mlx5_ib_add+0x4b/0x190 [mlx5_ib]
mlx5r_probe+0xd9/0x320 [mlx5_ib]
auxiliary_bus_probe+0x42/0x70
really_probe+0xdb/0x360
__driver_probe_device+0x8f/0x130
driver_probe_device+0x1f/0xb0
__driver_attach+0xd4/0x1f0
bus_for_each_dev+0x79/0xd0
bus_add_driver+0xf0/0x200
driver_register+0x6e/0xc0
__auxiliary_driver_register+0x6a/0xc0
do_one_initcall+0x5e/0x390
do_init_module+0x88/0x240
init_module_from_file+0x85/0xc0
idempotent_init_module+0x104/0x300
__x64_sys_finit_module+0x68/0xc0
do_syscall_64+0x6d/0x140
entry_SYSCALL_64_after_hwframe+0x4b/0x53
-> #1 (&dev->cache.rb_lock){+.+.}-{4:4}:
__mutex_lock+0x98/0xf10
__mlx5_ib_dereg_mr+0x6f2/0x890 [mlx5_ib]
mlx5_ib_dereg_mr+0x21/0x110 [mlx5_ib]
ib_dereg_mr_user+0x85/0x1f0 [ib_core]
uverbs_free_mr+0x19/0x30 [ib_uverbs]
destroy_hw_idr_uobject+0x21/0x80 [ib_uverbs]
uverbs_destroy_uobject+0x60/0x3d0 [ib_uverbs]
uobj_destroy+0x57/0xa0 [ib_uverbs]
ib_uverbs_cmd_verbs+0x4d5/0x1210 [ib_uverbs]
ib_uverbs_ioctl+0x129/0x230 [ib_uverbs]
__x64_sys_ioctl+0x596/0xaa0
do_syscall_64+0x6d/0x140
entry_SYSCALL_64_after_hwframe+0x4b/0x53
-> #0 (&umem_odp->umem_mutex){+.+.}-{4:4}:
__lock_acquire+0x1826/0x2f00
lock_acquire+0xd3/0x2e0
__mutex_lock+0x98/0xf10
mlx5_ib_invalidate_range+0x5b/0x550 [mlx5_ib]
__mmu_notifier_invalidate_range_start+0x18e/0x1f0
unmap_vmas+0x182/0x1a0
exit_mmap+0xf3/0x4a0
mmput+0x3a/0x100
do_exit+0x2b9/0xa90
do_group_exit+0x32/0xa0
get_signal+0xc32/0xcb0
arch_do_signal_or_restart+0x29/0x1d0
syscall_exit_to_user_mode+0x105/0x1d0
do_syscall_64+0x79/0x140
entry_SYSCALL_64_after_hwframe+0x4b/0x53
Chain exists of:
&dev->cache.rb_lock --> mmu_notifier_invalidate_range_start -->
&umem_odp->umem_mutex
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&umem_odp->umem_mutex);
lock(mmu_notifier_invalidate_range_start);
lock(&umem_odp->umem_mutex);
lock(&dev->cache.rb_lock);
*** DEADLOCK ***
Fixes: abb604a ("RDMA/mlx5: Fix a race for an ODP MR which leads to CQE with error")
Signed-off-by: Or Har-Toov <ohartoov@nvidia.com>
Reviewed-by: Michael Guralnik <michaelgur@nvidia.com>
Link: https://patch.msgid.link/3c8f225a8a9fade647d19b014df1172544643e4a.1750061612.git.leon@kernel.org
Signed-off-by: Leon Romanovsky <leon@kernel.org>
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When I run the NVME over TCP test in virtme-ng, I get the following "suspicious RCU usage" warning in nvme_mpath_add_sysfs_link(): ''' [ 5.024557][ T44] nvmet: Created nvm controller 1 for subsystem nqn.2025-06.org.nvmexpress.mptcp for NQN nqn.2014-08.org.nvmexpress:uuid:f7f6b5e0-ff97-4894-98ac-c85309e0bc77. [ 5.027401][ T183] nvme nvme0: creating 2 I/O queues. [ 5.029017][ T183] nvme nvme0: mapped 2/0/0 default/read/poll queues. [ 5.032587][ T183] nvme nvme0: new ctrl: NQN "nqn.2025-06.org.nvmexpress.mptcp", addr 127.0.0.1:4420, hostnqn: nqn.2014-08.org.nvmexpress:uuid:f7f6b5e0-ff97-4894-98ac-c85309e0bc77 [ 5.042214][ T25] [ 5.042440][ T25] ============================= [ 5.042579][ T25] WARNING: suspicious RCU usage [ 5.042705][ T25] 6.16.0-rc3+ #23 Not tainted [ 5.042812][ T25] ----------------------------- [ 5.042934][ T25] drivers/nvme/host/multipath.c:1203 RCU-list traversed in non-reader section!! [ 5.043111][ T25] [ 5.043111][ T25] other info that might help us debug this: [ 5.043111][ T25] [ 5.043341][ T25] [ 5.043341][ T25] rcu_scheduler_active = 2, debug_locks = 1 [ 5.043502][ T25] 3 locks held by kworker/u9:0/25: [ 5.043615][ T25] #0: ffff888008730948 ((wq_completion)async){+.+.}-{0:0}, at: process_one_work+0x7ed/0x1350 [ 5.043830][ T25] #1: ffffc900001afd40 ((work_completion)(&entry->work)){+.+.}-{0:0}, at: process_one_work+0xcf3/0x1350 [ 5.044084][ T25] #2: ffff888013ee0020 (&head->srcu){.+.+}-{0:0}, at: nvme_mpath_add_sysfs_link.part.0+0xb4/0x3a0 [ 5.044300][ T25] [ 5.044300][ T25] stack backtrace: [ 5.044439][ T25] CPU: 0 UID: 0 PID: 25 Comm: kworker/u9:0 Not tainted 6.16.0-rc3+ #23 PREEMPT(full) [ 5.044441][ T25] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 [ 5.044442][ T25] Workqueue: async async_run_entry_fn [ 5.044445][ T25] Call Trace: [ 5.044446][ T25] <TASK> [ 5.044449][ T25] dump_stack_lvl+0x6f/0xb0 [ 5.044453][ T25] lockdep_rcu_suspicious.cold+0x4f/0xb1 [ 5.044457][ T25] nvme_mpath_add_sysfs_link.part.0+0x2fb/0x3a0 [ 5.044459][ T25] ? queue_work_on+0x90/0xf0 [ 5.044461][ T25] ? lockdep_hardirqs_on+0x78/0x110 [ 5.044466][ T25] nvme_mpath_set_live+0x1e9/0x4f0 [ 5.044470][ T25] nvme_mpath_add_disk+0x240/0x2f0 [ 5.044472][ T25] ? __pfx_nvme_mpath_add_disk+0x10/0x10 [ 5.044475][ T25] ? add_disk_fwnode+0x361/0x580 [ 5.044480][ T25] nvme_alloc_ns+0x81c/0x17c0 [ 5.044483][ T25] ? kasan_quarantine_put+0x104/0x240 [ 5.044487][ T25] ? __pfx_nvme_alloc_ns+0x10/0x10 [ 5.044495][ T25] ? __pfx_nvme_find_get_ns+0x10/0x10 [ 5.044496][ T25] ? rcu_read_lock_any_held+0x45/0xa0 [ 5.044498][ T25] ? validate_chain+0x232/0x4f0 [ 5.044503][ T25] nvme_scan_ns+0x4c8/0x810 [ 5.044506][ T25] ? __pfx_nvme_scan_ns+0x10/0x10 [ 5.044508][ T25] ? find_held_lock+0x2b/0x80 [ 5.044512][ T25] ? ktime_get+0x16d/0x220 [ 5.044517][ T25] ? kvm_clock_get_cycles+0x18/0x30 [ 5.044520][ T25] ? __pfx_nvme_scan_ns_async+0x10/0x10 [ 5.044522][ T25] async_run_entry_fn+0x97/0x560 [ 5.044523][ T25] ? rcu_is_watching+0x12/0xc0 [ 5.044526][ T25] process_one_work+0xd3c/0x1350 [ 5.044532][ T25] ? __pfx_process_one_work+0x10/0x10 [ 5.044536][ T25] ? assign_work+0x16c/0x240 [ 5.044539][ T25] worker_thread+0x4da/0xd50 [ 5.044545][ T25] ? __pfx_worker_thread+0x10/0x10 [ 5.044546][ T25] kthread+0x356/0x5c0 [ 5.044548][ T25] ? __pfx_kthread+0x10/0x10 [ 5.044549][ T25] ? ret_from_fork+0x1b/0x2e0 [ 5.044552][ T25] ? __lock_release.isra.0+0x5d/0x180 [ 5.044553][ T25] ? ret_from_fork+0x1b/0x2e0 [ 5.044555][ T25] ? rcu_is_watching+0x12/0xc0 [ 5.044557][ T25] ? __pfx_kthread+0x10/0x10 [ 5.044559][ T25] ret_from_fork+0x218/0x2e0 [ 5.044561][ T25] ? __pfx_kthread+0x10/0x10 [ 5.044562][ T25] ret_from_fork_asm+0x1a/0x30 [ 5.044570][ T25] </TASK> ''' This patch uses sleepable RCU version of helper list_for_each_entry_srcu() instead of list_for_each_entry_rcu() to fix it. Fixes: 4dbd2b2 ("nvme-multipath: Add visibility for round-robin io-policy") Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn> Reviewed-by: Keith Busch <kbusch@kernel.org> Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Nilay Shroff <nilay@linux.ibm.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
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With VIRTCHNL2_CAP_MACFILTER enabled, the following warning is generated
on module load:
[ 324.701677] BUG: sleeping function called from invalid context at kernel/locking/mutex.c:578
[ 324.701684] in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 1582, name: NetworkManager
[ 324.701689] preempt_count: 201, expected: 0
[ 324.701693] RCU nest depth: 0, expected: 0
[ 324.701697] 2 locks held by NetworkManager/1582:
[ 324.701702] #0: ffffffff9f7be770 (rtnl_mutex){....}-{3:3}, at: rtnl_newlink+0x791/0x21e0
[ 324.701730] #1: ff1100216c380368 (_xmit_ETHER){....}-{2:2}, at: __dev_open+0x3f0/0x870
[ 324.701749] Preemption disabled at:
[ 324.701752] [<ffffffff9cd23b9d>] __dev_open+0x3dd/0x870
[ 324.701765] CPU: 30 UID: 0 PID: 1582 Comm: NetworkManager Not tainted 6.15.0-rc5+ #2 PREEMPT(voluntary)
[ 324.701771] Hardware name: Intel Corporation M50FCP2SBSTD/M50FCP2SBSTD, BIOS SE5C741.86B.01.01.0001.2211140926 11/14/2022
[ 324.701774] Call Trace:
[ 324.701777] <TASK>
[ 324.701779] dump_stack_lvl+0x5d/0x80
[ 324.701788] ? __dev_open+0x3dd/0x870
[ 324.701793] __might_resched.cold+0x1ef/0x23d
<..>
[ 324.701818] __mutex_lock+0x113/0x1b80
<..>
[ 324.701917] idpf_ctlq_clean_sq+0xad/0x4b0 [idpf]
[ 324.701935] ? kasan_save_track+0x14/0x30
[ 324.701941] idpf_mb_clean+0x143/0x380 [idpf]
<..>
[ 324.701991] idpf_send_mb_msg+0x111/0x720 [idpf]
[ 324.702009] idpf_vc_xn_exec+0x4cc/0x990 [idpf]
[ 324.702021] ? rcu_is_watching+0x12/0xc0
[ 324.702035] idpf_add_del_mac_filters+0x3ed/0xb50 [idpf]
<..>
[ 324.702122] __hw_addr_sync_dev+0x1cf/0x300
[ 324.702126] ? find_held_lock+0x32/0x90
[ 324.702134] idpf_set_rx_mode+0x317/0x390 [idpf]
[ 324.702152] __dev_open+0x3f8/0x870
[ 324.702159] ? __pfx___dev_open+0x10/0x10
[ 324.702174] __dev_change_flags+0x443/0x650
<..>
[ 324.702208] netif_change_flags+0x80/0x160
[ 324.702218] do_setlink.isra.0+0x16a0/0x3960
<..>
[ 324.702349] rtnl_newlink+0x12fd/0x21e0
The sequence is as follows:
rtnl_newlink()->
__dev_change_flags()->
__dev_open()->
dev_set_rx_mode() - > # disables BH and grabs "dev->addr_list_lock"
idpf_set_rx_mode() -> # proceed only if VIRTCHNL2_CAP_MACFILTER is ON
__dev_uc_sync() ->
idpf_add_mac_filter ->
idpf_add_del_mac_filters ->
idpf_send_mb_msg() ->
idpf_mb_clean() ->
idpf_ctlq_clean_sq() # mutex_lock(cq_lock)
Fix by converting cq_lock to a spinlock. All operations under the new
lock are safe except freeing the DMA memory, which may use vunmap(). Fix
by requesting a contiguous physical memory for the DMA mapping.
Fixes: a251eee ("idpf: add SRIOV support and other ndo_ops")
Reviewed-by: Aleksandr Loktionov <aleksandr.loktionov@intel.com>
Signed-off-by: Ahmed Zaki <ahmed.zaki@intel.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Tested-by: Samuel Salin <Samuel.salin@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
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Jul 14, 2025
…-flight
Reject migration of SEV{-ES} state if either the source or destination VM
is actively creating a vCPU, i.e. if kvm_vm_ioctl_create_vcpu() is in the
section between incrementing created_vcpus and online_vcpus. The bulk of
vCPU creation runs _outside_ of kvm->lock to allow creating multiple vCPUs
in parallel, and so sev_info.es_active can get toggled from false=>true in
the destination VM after (or during) svm_vcpu_create(), resulting in an
SEV{-ES} VM effectively having a non-SEV{-ES} vCPU.
The issue manifests most visibly as a crash when trying to free a vCPU's
NULL VMSA page in an SEV-ES VM, but any number of things can go wrong.
BUG: unable to handle page fault for address: ffffebde00000000
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD 0 P4D 0
Oops: Oops: 0000 [#1] SMP KASAN NOPTI
CPU: 227 UID: 0 PID: 64063 Comm: syz.5.60023 Tainted: G U O 6.15.0-smp-DEV #2 NONE
Tainted: [U]=USER, [O]=OOT_MODULE
Hardware name: Google, Inc. Arcadia_IT_80/Arcadia_IT_80, BIOS 12.52.0-0 10/28/2024
RIP: 0010:constant_test_bit arch/x86/include/asm/bitops.h:206 [inline]
RIP: 0010:arch_test_bit arch/x86/include/asm/bitops.h:238 [inline]
RIP: 0010:_test_bit include/asm-generic/bitops/instrumented-non-atomic.h:142 [inline]
RIP: 0010:PageHead include/linux/page-flags.h:866 [inline]
RIP: 0010:___free_pages+0x3e/0x120 mm/page_alloc.c:5067
Code: <49> f7 06 40 00 00 00 75 05 45 31 ff eb 0c 66 90 4c 89 f0 4c 39 f0
RSP: 0018:ffff8984551978d0 EFLAGS: 00010246
RAX: 0000777f80000001 RBX: 0000000000000000 RCX: ffffffff918aeb98
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffebde00000000
RBP: 0000000000000000 R08: ffffebde00000007 R09: 1ffffd7bc0000000
R10: dffffc0000000000 R11: fffff97bc0000001 R12: dffffc0000000000
R13: ffff8983e19751a8 R14: ffffebde00000000 R15: 1ffffd7bc0000000
FS: 0000000000000000(0000) GS:ffff89ee661d3000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffebde00000000 CR3: 000000793ceaa000 CR4: 0000000000350ef0
DR0: 0000000000000000 DR1: 0000000000000b5f DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
sev_free_vcpu+0x413/0x630 arch/x86/kvm/svm/sev.c:3169
svm_vcpu_free+0x13a/0x2a0 arch/x86/kvm/svm/svm.c:1515
kvm_arch_vcpu_destroy+0x6a/0x1d0 arch/x86/kvm/x86.c:12396
kvm_vcpu_destroy virt/kvm/kvm_main.c:470 [inline]
kvm_destroy_vcpus+0xd1/0x300 virt/kvm/kvm_main.c:490
kvm_arch_destroy_vm+0x636/0x820 arch/x86/kvm/x86.c:12895
kvm_put_kvm+0xb8e/0xfb0 virt/kvm/kvm_main.c:1310
kvm_vm_release+0x48/0x60 virt/kvm/kvm_main.c:1369
__fput+0x3e4/0x9e0 fs/file_table.c:465
task_work_run+0x1a9/0x220 kernel/task_work.c:227
exit_task_work include/linux/task_work.h:40 [inline]
do_exit+0x7f0/0x25b0 kernel/exit.c:953
do_group_exit+0x203/0x2d0 kernel/exit.c:1102
get_signal+0x1357/0x1480 kernel/signal.c:3034
arch_do_signal_or_restart+0x40/0x690 arch/x86/kernel/signal.c:337
exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline]
__syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
syscall_exit_to_user_mode+0x67/0xb0 kernel/entry/common.c:218
do_syscall_64+0x7c/0x150 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7f87a898e969
</TASK>
Modules linked in: gq(O)
gsmi: Log Shutdown Reason 0x03
CR2: ffffebde00000000
---[ end trace 0000000000000000 ]---
Deliberately don't check for a NULL VMSA when freeing the vCPU, as crashing
the host is likely desirable due to the VMSA being consumed by hardware.
E.g. if KVM manages to allow VMRUN on the vCPU, hardware may read/write a
bogus VMSA page. Accessing PFN 0 is "fine"-ish now that it's sequestered
away thanks to L1TF, but panicking in this scenario is preferable to
potentially running with corrupted state.
Reported-by: Alexander Potapenko <glider@google.com>
Tested-by: Alexander Potapenko <glider@google.com>
Fixes: 0b020f5 ("KVM: SEV: Add support for SEV-ES intra host migration")
Fixes: b566393 ("KVM: SEV: Add support for SEV intra host migration")
Cc: stable@vger.kernel.org
Cc: James Houghton <jthoughton@google.com>
Cc: Peter Gonda <pgonda@google.com>
Reviewed-by: Liam Merwick <liam.merwick@oracle.com>
Tested-by: Liam Merwick <liam.merwick@oracle.com>
Reviewed-by: James Houghton <jthoughton@google.com>
Link: https://lore.kernel.org/r/20250602224459.41505-2-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
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If the PHY driver uses another PHY internally (e.g. in case of eUSB2,
repeaters are represented as PHYs), then it would trigger the following
lockdep splat because all PHYs use a single static lockdep key and thus
lockdep can not identify whether there is a dependency or not and
reports a false positive.
Make PHY subsystem use dynamic lockdep keys, assigning each driver a
separate key. This way lockdep can correctly identify dependency graph
between mutexes.
============================================
WARNING: possible recursive locking detected
6.15.0-rc7-next-20250522-12896-g3932f283970c #3455 Not tainted
--------------------------------------------
kworker/u51:0/78 is trying to acquire lock:
ffff0008116554f0 (&phy->mutex){+.+.}-{4:4}, at: phy_init+0x4c/0x12c
but task is already holding lock:
ffff000813c10cf0 (&phy->mutex){+.+.}-{4:4}, at: phy_init+0x4c/0x12c
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(&phy->mutex);
lock(&phy->mutex);
*** DEADLOCK ***
May be due to missing lock nesting notation
4 locks held by kworker/u51:0/78:
#0: ffff000800010948 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x18c/0x5ec
#1: ffff80008036bdb0 (deferred_probe_work){+.+.}-{0:0}, at: process_one_work+0x1b4/0x5ec
#2: ffff0008094ac8f8 (&dev->mutex){....}-{4:4}, at: __device_attach+0x38/0x188
#3: ffff000813c10cf0 (&phy->mutex){+.+.}-{4:4}, at: phy_init+0x4c/0x12c
stack backtrace:
CPU: 0 UID: 0 PID: 78 Comm: kworker/u51:0 Not tainted 6.15.0-rc7-next-20250522-12896-g3932f283970c #3455 PREEMPT
Hardware name: Qualcomm CRD, BIOS 6.0.240904.BOOT.MXF.2.4-00528.1-HAMOA-1 09/ 4/2024
Workqueue: events_unbound deferred_probe_work_func
Call trace:
show_stack+0x18/0x24 (C)
dump_stack_lvl+0x90/0xd0
dump_stack+0x18/0x24
print_deadlock_bug+0x258/0x348
__lock_acquire+0x10fc/0x1f84
lock_acquire+0x1c8/0x338
__mutex_lock+0xb8/0x59c
mutex_lock_nested+0x24/0x30
phy_init+0x4c/0x12c
snps_eusb2_hsphy_init+0x54/0x1a0
phy_init+0xe0/0x12c
dwc3_core_init+0x450/0x10b4
dwc3_core_probe+0xce4/0x15fc
dwc3_probe+0x64/0xb0
platform_probe+0x68/0xc4
really_probe+0xbc/0x298
__driver_probe_device+0x78/0x12c
driver_probe_device+0x3c/0x160
__device_attach_driver+0xb8/0x138
bus_for_each_drv+0x84/0xe0
__device_attach+0x9c/0x188
device_initial_probe+0x14/0x20
bus_probe_device+0xac/0xb0
deferred_probe_work_func+0x8c/0xc8
process_one_work+0x208/0x5ec
worker_thread+0x1c0/0x368
kthread+0x14c/0x20c
ret_from_fork+0x10/0x20
Fixes: 3584f63 ("phy: qcom: phy-qcom-snps-eusb2: Add support for eUSB2 repeater")
Fixes: e246355 ("phy: amlogic: Add Amlogic AXG PCIE PHY Driver")
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Reviewed-by: Abel Vesa <abel.vesa@linaro.org>
Reported-by: Johan Hovold <johan+linaro@kernel.org>
Link: https://lore.kernel.org/lkml/ZnpoAVGJMG4Zu-Jw@hovoldconsulting.com/
Reviewed-by: Johan Hovold <johan+linaro@kernel.org>
Tested-by: Johan Hovold <johan+linaro@kernel.org>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Link: https://lore.kernel.org/r/20250605-phy-subinit-v3-1-1e1e849e10cd@oss.qualcomm.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
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If "try_verify_in_tasklet" is set for dm-verity, DM_BUFIO_CLIENT_NO_SLEEP
is enabled for dm-bufio. However, when bufio tries to evict buffers, there
is a chance to trigger scheduling in spin_lock_bh, the following warning
is hit:
BUG: sleeping function called from invalid context at drivers/md/dm-bufio.c:2745
in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 123, name: kworker/2:2
preempt_count: 201, expected: 0
RCU nest depth: 0, expected: 0
4 locks held by kworker/2:2/123:
#0: ffff88800a2d1548 ((wq_completion)dm_bufio_cache){....}-{0:0}, at: process_one_work+0xe46/0x1970
#1: ffffc90000d97d20 ((work_completion)(&dm_bufio_replacement_work)){....}-{0:0}, at: process_one_work+0x763/0x1970
#2: ffffffff8555b528 (dm_bufio_clients_lock){....}-{3:3}, at: do_global_cleanup+0x1ce/0x710
#3: ffff88801d5820b8 (&c->spinlock){....}-{2:2}, at: do_global_cleanup+0x2a5/0x710
Preemption disabled at:
[<0000000000000000>] 0x0
CPU: 2 UID: 0 PID: 123 Comm: kworker/2:2 Not tainted 6.16.0-rc3-g90548c634bd0 #305 PREEMPT(voluntary)
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014
Workqueue: dm_bufio_cache do_global_cleanup
Call Trace:
<TASK>
dump_stack_lvl+0x53/0x70
__might_resched+0x360/0x4e0
do_global_cleanup+0x2f5/0x710
process_one_work+0x7db/0x1970
worker_thread+0x518/0xea0
kthread+0x359/0x690
ret_from_fork+0xf3/0x1b0
ret_from_fork_asm+0x1a/0x30
</TASK>
That can be reproduced by:
veritysetup format --data-block-size=4096 --hash-block-size=4096 /dev/vda /dev/vdb
SIZE=$(blockdev --getsz /dev/vda)
dmsetup create myverity -r --table "0 $SIZE verity 1 /dev/vda /dev/vdb 4096 4096 <data_blocks> 1 sha256 <root_hash> <salt> 1 try_verify_in_tasklet"
mount /dev/dm-0 /mnt -o ro
echo 102400 > /sys/module/dm_bufio/parameters/max_cache_size_bytes
[read files in /mnt]
Cc: stable@vger.kernel.org # v6.4+
Fixes: 450e8de ("dm bufio: improve concurrent IO performance")
Signed-off-by: Wang Shuai <wangshuai12@xiaomi.com>
Signed-off-by: Sheng Yong <shengyong1@xiaomi.com>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
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This reverts commit 7796c97. This patch broke Dragonboard 845c (sdm845). I see: Unexpected kernel BRK exception at EL1 Internal error: BRK handler: 00000000f20003e8 [#1] SMP pc : qcom_swrm_set_channel_map+0x7c/0x80 [soundwire_qcom] lr : snd_soc_dai_set_channel_map+0x34/0x78 Call trace: qcom_swrm_set_channel_map+0x7c/0x80 [soundwire_qcom] (P) sdm845_dai_init+0x18c/0x2e0 [snd_soc_sdm845] snd_soc_link_init+0x28/0x6c snd_soc_bind_card+0x5f4/0xb0c snd_soc_register_card+0x148/0x1a4 devm_snd_soc_register_card+0x50/0xb0 sdm845_snd_platform_probe+0x124/0x148 [snd_soc_sdm845] platform_probe+0x6c/0xd0 really_probe+0xc0/0x2a4 __driver_probe_device+0x7c/0x130 driver_probe_device+0x40/0x118 __device_attach_driver+0xc4/0x108 bus_for_each_drv+0x8c/0xf0 __device_attach+0xa4/0x198 device_initial_probe+0x18/0x28 bus_probe_device+0xb8/0xbc deferred_probe_work_func+0xac/0xfc process_one_work+0x244/0x658 worker_thread+0x1b4/0x360 kthread+0x148/0x228 ret_from_fork+0x10/0x20 Kernel panic - not syncing: BRK handler: Fatal exception Dan has also reported following issues with the original patch https://lore.kernel.org/all/33fe8fe7-719a-405a-9ed2-d9f816ce1d57@sabinyo.mountain/ Bug #1: The zeroeth element of ctrl->pconfig[] is supposed to be unused. We start counting at 1. However this code sets ctrl->pconfig[0].ch_mask = 128. Bug #2: There are SLIM_MAX_TX_PORTS (16) elements in tx_ch[] array but only QCOM_SDW_MAX_PORTS + 1 (15) in the ctrl->pconfig[] array so it corrupts memory like Yongqin Liu pointed out. Bug 3: Like Jie Gan pointed out, it erases all the tx information with the rx information. Cc: stable@vger.kernel.org # v6.15+ Signed-off-by: Amit Pundir <amit.pundir@linaro.org> Acked-by: Srinivas Kandagatla <srini@kernel.org> Link: https://lore.kernel.org/r/20250709174949.8541-1-amit.pundir@linaro.org Signed-off-by: Vinod Koul <vkoul@kernel.org>
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into HEAD KVM/riscv fixes for 6.16, take #2 - Disable vstimecmp before exiting to user-space - Move HGEI[E|P] CSR access to IMSIC virtualization
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…git/rostedt/linux-ktest
Pull ktest updates from Steven Rostedt:
- Add new -D option that allows to override variables and options
For example:
./ktest.pl -DPATCH_START:=HEAD~1 -DOUTPUT_DIR=/work/build/urgent config
The above sets the variable "PATCH_START" to HEAD~1 and the
OUTPUT_DIR option to "/work/build/urgent".
This is useful because currently the only way to make a slight change
to a config file is by modifying that config file. For one time
changes, this can be annoying. Having a way to do a one time override
from the command line simplifies the workflow.
Temp variables (PATCH_START) will override every temp variable in the
config file, whereas options will act like a normal OVERRIDE option
and will only affect the session they define.
-DBUILD_OUTPUT=/work/git/linux.git
Replaces the default BUILD_OUTPUT option.
'-DBUILD_OUTPUT[2]=/work/git/linux.git'
Only replaces the BUILD_OUTPUT variable for test #2.
- If an option contains itself, just drop it instead of going into an
infinite loop and failing to parse (it doesn't crash, it detects the
recursion after 100 iterations anyway).
Some configs may define a variable with the same name as the option:
ADD_CONFIG := $(ADD_CONFIG)
But if the option doesn't exist, it the above will fail to parse. In
these cases, just ignore evaluating the option inside the definition
of another option if it has the same name.
- Display the BUILD_DIR and OUTPUT_DIR options at the start of every
test
It is useful to know which kernel source and what destination a test
is using when it starts, in case a mistake is made. This makes it
easier to abort the test if the wrong source or destination is being
used instead of waiting until the test completes.
- Add new PATCHCHECK_SKIP option
When testing a series of commits that also includes changes to the
Linux tools directory, it is useless to test the changes in tools as
they may not affect the kernel itself. Doing tests on the kernel for
changes that do not affect the kernel is a waste of time.
Add a PATCHCHECK_SKIP that takes a series of shas that will be
skipped while doing the individual commit tests.
* tag 'ktest-v6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-ktest:
ktest.pl: Add new PATCHCHECK_SKIP option to skip testing individual commits
ktest.pl: Always display BUILD_DIR and OUTPUT_DIR at the start of tests
ktest.pl: Prevent recursion of default variable options
ktest.pl: Have -D option work without a space
ktest.pl: Allow command option -D to override temp variables
ktest.pl: Add -D option to override options
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With KASAN enabled, it is possible to get a slab out of bounds during mount to ksmbd due to missing check in parse_server_interfaces() (see below): BUG: KASAN: slab-out-of-bounds in parse_server_interfaces+0x14ee/0x1880 [cifs] Read of size 4 at addr ffff8881433dba98 by task mount/9827 CPU: 5 UID: 0 PID: 9827 Comm: mount Tainted: G OE 6.16.0-rc2-kasan #2 PREEMPT(voluntary) Tainted: [O]=OOT_MODULE, [E]=UNSIGNED_MODULE Hardware name: Dell Inc. Precision Tower 3620/0MWYPT, BIOS 2.13.1 06/14/2019 Call Trace: <TASK> dump_stack_lvl+0x9f/0xf0 print_report+0xd1/0x670 __virt_addr_valid+0x22c/0x430 ? parse_server_interfaces+0x14ee/0x1880 [cifs] ? kasan_complete_mode_report_info+0x2a/0x1f0 ? parse_server_interfaces+0x14ee/0x1880 [cifs] kasan_report+0xd6/0x110 parse_server_interfaces+0x14ee/0x1880 [cifs] __asan_report_load_n_noabort+0x13/0x20 parse_server_interfaces+0x14ee/0x1880 [cifs] ? __pfx_parse_server_interfaces+0x10/0x10 [cifs] ? trace_hardirqs_on+0x51/0x60 SMB3_request_interfaces+0x1ad/0x3f0 [cifs] ? __pfx_SMB3_request_interfaces+0x10/0x10 [cifs] ? SMB2_tcon+0x23c/0x15d0 [cifs] smb3_qfs_tcon+0x173/0x2b0 [cifs] ? __pfx_smb3_qfs_tcon+0x10/0x10 [cifs] ? cifs_get_tcon+0x105d/0x2120 [cifs] ? do_raw_spin_unlock+0x5d/0x200 ? cifs_get_tcon+0x105d/0x2120 [cifs] ? __pfx_smb3_qfs_tcon+0x10/0x10 [cifs] cifs_mount_get_tcon+0x369/0xb90 [cifs] ? dfs_cache_find+0xe7/0x150 [cifs] dfs_mount_share+0x985/0x2970 [cifs] ? check_path.constprop.0+0x28/0x50 ? save_trace+0x54/0x370 ? __pfx_dfs_mount_share+0x10/0x10 [cifs] ? __lock_acquire+0xb82/0x2ba0 ? __kasan_check_write+0x18/0x20 cifs_mount+0xbc/0x9e0 [cifs] ? __pfx_cifs_mount+0x10/0x10 [cifs] ? do_raw_spin_unlock+0x5d/0x200 ? cifs_setup_cifs_sb+0x29d/0x810 [cifs] cifs_smb3_do_mount+0x263/0x1990 [cifs] Reported-by: Namjae Jeon <linkinjeon@kernel.org> Tested-by: Namjae Jeon <linkinjeon@kernel.org> Cc: stable@vger.kernel.org Signed-off-by: Steve French <stfrench@microsoft.com>
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The commit under the Fixes tag added a netdev_assert_locked() in bnxt_free_ntp_fltrs(). The lock should be held during normal run-time but the assert will be triggered (see below) during bnxt_remove_one() which should not need the lock. The netdev is already unregistered by then. Fix it by calling netdev_assert_locked_or_invisible() which will not assert if the netdev is unregistered. WARNING: CPU: 5 PID: 2241 at ./include/net/netdev_lock.h:17 bnxt_free_ntp_fltrs+0xf8/0x100 [bnxt_en] Modules linked in: rpcrdma rdma_cm iw_cm ib_cm configfs ib_core bnxt_en(-) bridge stp llc x86_pkg_temp_thermal xfs tg3 [last unloaded: bnxt_re] CPU: 5 UID: 0 PID: 2241 Comm: rmmod Tainted: G S W 6.16.0 #2 PREEMPT(voluntary) Tainted: [S]=CPU_OUT_OF_SPEC, [W]=WARN Hardware name: Dell Inc. PowerEdge R730/072T6D, BIOS 2.4.3 01/17/2017 RIP: 0010:bnxt_free_ntp_fltrs+0xf8/0x100 [bnxt_en] Code: 41 5c 41 5d 41 5e 41 5f c3 cc cc cc cc 48 8b 47 60 be ff ff ff ff 48 8d b8 28 0c 00 00 e8 d0 cf 41 c3 85 c0 0f 85 2e ff ff ff <0f> 0b e9 27 ff ff ff 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 RSP: 0018:ffffa92082387da0 EFLAGS: 00010246 RAX: 0000000000000000 RBX: ffff9e5b593d8000 RCX: 0000000000000001 RDX: 0000000000000001 RSI: ffffffff83dc9a70 RDI: ffffffff83e1a1cf RBP: ffff9e5b593d8c80 R08: 0000000000000000 R09: ffffffff8373a2b3 R10: 000000008100009f R11: 0000000000000001 R12: 0000000000000001 R13: ffffffffc01c4478 R14: dead000000000122 R15: dead000000000100 FS: 00007f3a8a52c740(0000) GS:ffff9e631ad1c000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055bb289419c8 CR3: 000000011274e001 CR4: 00000000003706f0 Call Trace: <TASK> bnxt_remove_one+0x57/0x180 [bnxt_en] pci_device_remove+0x39/0xc0 device_release_driver_internal+0xa5/0x130 driver_detach+0x42/0x90 bus_remove_driver+0x61/0xc0 pci_unregister_driver+0x38/0x90 bnxt_exit+0xc/0x7d0 [bnxt_en] Fixes: 004b500 ("eth: bnxt: remove most dependencies on RTNL") Reviewed-by: Pavan Chebbi <pavan.chebbi@broadcom.com> Signed-off-by: Michael Chan <michael.chan@broadcom.com> Reviewed-by: Vadim Fedorenko <vadim.fedorenko@linux.dev> Link: https://patch.msgid.link/20250816183850.4125033-1-michael.chan@broadcom.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Commit 3c7ac40 ("scsi: ufs: core: Delegate the interrupt service routine to a threaded IRQ handler") introduced an IRQ lock inversion issue. Fix this lock inversion by changing the spin_lock_irq() calls into spin_lock_irqsave() calls in code that can be called either from interrupt context or from thread context. This patch fixes the following lockdep complaint: WARNING: possible irq lock inversion dependency detected 6.12.30-android16-5-maybe-dirty-4k #1 Tainted: G W OE -------------------------------------------------------- kworker/u28:0/12 just changed the state of lock: ffffff881e29dd60 (&hba->clk_gating.lock){-...}-{2:2}, at: ufshcd_release_scsi_cmd+0x60/0x110 but this lock took another, HARDIRQ-unsafe lock in the past: (shost->host_lock){+.+.}-{2:2} and interrupts could create inverse lock ordering between them. other info that might help us debug this: Possible interrupt unsafe locking scenario: CPU0 CPU1 ---- ---- lock(shost->host_lock); local_irq_disable(); lock(&hba->clk_gating.lock); lock(shost->host_lock); <Interrupt> lock(&hba->clk_gating.lock); *** DEADLOCK *** 4 locks held by kworker/u28:0/12: #0: ffffff8800ac6158 ((wq_completion)async){+.+.}-{0:0}, at: process_one_work+0x1bc/0x65c #1: ffffffc085c93d70 ((work_completion)(&entry->work)){+.+.}-{0:0}, at: process_one_work+0x1e4/0x65c #2: ffffff881e29c0e0 (&shost->scan_mutex){+.+.}-{3:3}, at: __scsi_add_device+0x74/0x120 #3: ffffff881960ea00 (&hwq->cq_lock){-...}-{2:2}, at: ufshcd_mcq_poll_cqe_lock+0x28/0x104 the shortest dependencies between 2nd lock and 1st lock: -> (shost->host_lock){+.+.}-{2:2} { HARDIRQ-ON-W at: lock_acquire+0x134/0x2b4 _raw_spin_lock+0x48/0x64 ufshcd_sl_intr+0x4c/0xa08 ufshcd_threaded_intr+0x70/0x12c irq_thread_fn+0x48/0xa8 irq_thread+0x130/0x1ec kthread+0x110/0x134 ret_from_fork+0x10/0x20 SOFTIRQ-ON-W at: lock_acquire+0x134/0x2b4 _raw_spin_lock+0x48/0x64 ufshcd_sl_intr+0x4c/0xa08 ufshcd_threaded_intr+0x70/0x12c irq_thread_fn+0x48/0xa8 irq_thread+0x130/0x1ec kthread+0x110/0x134 ret_from_fork+0x10/0x20 INITIAL USE at: lock_acquire+0x134/0x2b4 _raw_spin_lock+0x48/0x64 ufshcd_sl_intr+0x4c/0xa08 ufshcd_threaded_intr+0x70/0x12c irq_thread_fn+0x48/0xa8 irq_thread+0x130/0x1ec kthread+0x110/0x134 ret_from_fork+0x10/0x20 } ... key at: [<ffffffc085ba1a98>] scsi_host_alloc.__key+0x0/0x10 ... acquired at: _raw_spin_lock_irqsave+0x5c/0x80 __ufshcd_release+0x78/0x118 ufshcd_send_uic_cmd+0xe4/0x118 ufshcd_dme_set_attr+0x88/0x1c8 ufs_google_phy_initialization+0x68/0x418 [ufs] ufs_google_link_startup_notify+0x78/0x27c [ufs] ufshcd_link_startup+0x84/0x720 ufshcd_init+0xf3c/0x1330 ufshcd_pltfrm_init+0x728/0x7d8 ufs_google_probe+0x30/0x84 [ufs] platform_probe+0xa0/0xe0 really_probe+0x114/0x454 __driver_probe_device+0xa4/0x160 driver_probe_device+0x44/0x23c __driver_attach_async_helper+0x60/0xd4 async_run_entry_fn+0x4c/0x17c process_one_work+0x26c/0x65c worker_thread+0x33c/0x498 kthread+0x110/0x134 ret_from_fork+0x10/0x20 -> (&hba->clk_gating.lock){-...}-{2:2} { IN-HARDIRQ-W at: lock_acquire+0x134/0x2b4 _raw_spin_lock_irqsave+0x5c/0x80 ufshcd_release_scsi_cmd+0x60/0x110 ufshcd_compl_one_cqe+0x2c0/0x3f4 ufshcd_mcq_poll_cqe_lock+0xb0/0x104 ufs_google_mcq_intr+0x80/0xa0 [ufs] __handle_irq_event_percpu+0x104/0x32c handle_irq_event+0x40/0x9c handle_fasteoi_irq+0x170/0x2e8 generic_handle_domain_irq+0x58/0x80 gic_handle_irq+0x48/0x104 call_on_irq_stack+0x3c/0x50 do_interrupt_handler+0x7c/0xd8 el1_interrupt+0x34/0x58 el1h_64_irq_handler+0x18/0x24 el1h_64_irq+0x68/0x6c _raw_spin_unlock_irqrestore+0x3c/0x6c debug_object_assert_init+0x16c/0x21c __mod_timer+0x4c/0x48c schedule_timeout+0xd4/0x16c io_schedule_timeout+0x48/0x70 do_wait_for_common+0x100/0x194 wait_for_completion_io_timeout+0x48/0x6c blk_execute_rq+0x124/0x17c scsi_execute_cmd+0x18c/0x3f8 scsi_probe_and_add_lun+0x204/0xd74 __scsi_add_device+0xbc/0x120 ufshcd_async_scan+0x80/0x3c0 async_run_entry_fn+0x4c/0x17c process_one_work+0x26c/0x65c worker_thread+0x33c/0x498 kthread+0x110/0x134 ret_from_fork+0x10/0x20 INITIAL USE at: lock_acquire+0x134/0x2b4 _raw_spin_lock_irqsave+0x5c/0x80 ufshcd_hold+0x34/0x14c ufshcd_send_uic_cmd+0x28/0x118 ufshcd_dme_set_attr+0x88/0x1c8 ufs_google_phy_initialization+0x68/0x418 [ufs] ufs_google_link_startup_notify+0x78/0x27c [ufs] ufshcd_link_startup+0x84/0x720 ufshcd_init+0xf3c/0x1330 ufshcd_pltfrm_init+0x728/0x7d8 ufs_google_probe+0x30/0x84 [ufs] platform_probe+0xa0/0xe0 really_probe+0x114/0x454 __driver_probe_device+0xa4/0x160 driver_probe_device+0x44/0x23c __driver_attach_async_helper+0x60/0xd4 async_run_entry_fn+0x4c/0x17c process_one_work+0x26c/0x65c worker_thread+0x33c/0x498 kthread+0x110/0x134 ret_from_fork+0x10/0x20 } ... key at: [<ffffffc085ba6fe8>] ufshcd_init.__key+0x0/0x10 ... acquired at: mark_lock+0x1c4/0x224 __lock_acquire+0x438/0x2e1c lock_acquire+0x134/0x2b4 _raw_spin_lock_irqsave+0x5c/0x80 ufshcd_release_scsi_cmd+0x60/0x110 ufshcd_compl_one_cqe+0x2c0/0x3f4 ufshcd_mcq_poll_cqe_lock+0xb0/0x104 ufs_google_mcq_intr+0x80/0xa0 [ufs] __handle_irq_event_percpu+0x104/0x32c handle_irq_event+0x40/0x9c handle_fasteoi_irq+0x170/0x2e8 generic_handle_domain_irq+0x58/0x80 gic_handle_irq+0x48/0x104 call_on_irq_stack+0x3c/0x50 do_interrupt_handler+0x7c/0xd8 el1_interrupt+0x34/0x58 el1h_64_irq_handler+0x18/0x24 el1h_64_irq+0x68/0x6c _raw_spin_unlock_irqrestore+0x3c/0x6c debug_object_assert_init+0x16c/0x21c __mod_timer+0x4c/0x48c schedule_timeout+0xd4/0x16c io_schedule_timeout+0x48/0x70 do_wait_for_common+0x100/0x194 wait_for_completion_io_timeout+0x48/0x6c blk_execute_rq+0x124/0x17c scsi_execute_cmd+0x18c/0x3f8 scsi_probe_and_add_lun+0x204/0xd74 __scsi_add_device+0xbc/0x120 ufshcd_async_scan+0x80/0x3c0 async_run_entry_fn+0x4c/0x17c process_one_work+0x26c/0x65c worker_thread+0x33c/0x498 kthread+0x110/0x134 ret_from_fork+0x10/0x20 stack backtrace: CPU: 6 UID: 0 PID: 12 Comm: kworker/u28:0 Tainted: G W OE 6.12.30-android16-5-maybe-dirty-4k #1 ccd4020fe444bdf629efc3b86df6be920b8df7d0 Tainted: [W]=WARN, [O]=OOT_MODULE, [E]=UNSIGNED_MODULE Hardware name: Spacecraft board based on MALIBU (DT) Workqueue: async async_run_entry_fn Call trace: dump_backtrace+0xfc/0x17c show_stack+0x18/0x28 dump_stack_lvl+0x40/0xa0 dump_stack+0x18/0x24 print_irq_inversion_bug+0x2fc/0x304 mark_lock_irq+0x388/0x4fc mark_lock+0x1c4/0x224 __lock_acquire+0x438/0x2e1c lock_acquire+0x134/0x2b4 _raw_spin_lock_irqsave+0x5c/0x80 ufshcd_release_scsi_cmd+0x60/0x110 ufshcd_compl_one_cqe+0x2c0/0x3f4 ufshcd_mcq_poll_cqe_lock+0xb0/0x104 ufs_google_mcq_intr+0x80/0xa0 [ufs dd6f385554e109da094ab91d5f7be18625a2222a] __handle_irq_event_percpu+0x104/0x32c handle_irq_event+0x40/0x9c handle_fasteoi_irq+0x170/0x2e8 generic_handle_domain_irq+0x58/0x80 gic_handle_irq+0x48/0x104 call_on_irq_stack+0x3c/0x50 do_interrupt_handler+0x7c/0xd8 el1_interrupt+0x34/0x58 el1h_64_irq_handler+0x18/0x24 el1h_64_irq+0x68/0x6c _raw_spin_unlock_irqrestore+0x3c/0x6c debug_object_assert_init+0x16c/0x21c __mod_timer+0x4c/0x48c schedule_timeout+0xd4/0x16c io_schedule_timeout+0x48/0x70 do_wait_for_common+0x100/0x194 wait_for_completion_io_timeout+0x48/0x6c blk_execute_rq+0x124/0x17c scsi_execute_cmd+0x18c/0x3f8 scsi_probe_and_add_lun+0x204/0xd74 __scsi_add_device+0xbc/0x120 ufshcd_async_scan+0x80/0x3c0 async_run_entry_fn+0x4c/0x17c process_one_work+0x26c/0x65c worker_thread+0x33c/0x498 kthread+0x110/0x134 ret_from_fork+0x10/0x20 Cc: Neil Armstrong <neil.armstrong@linaro.org> Cc: André Draszik <andre.draszik@linaro.org> Reviewed-by: Peter Wang <peter.wang@mediatek.com> Fixes: 3c7ac40 ("scsi: ufs: core: Delegate the interrupt service routine to a threaded IRQ handler") Signed-off-by: Bart Van Assche <bvanassche@acm.org> Link: https://lore.kernel.org/r/20250815155842.472867-2-bvanassche@acm.org Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
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Jamal Hadi Salim says: ==================== net/sched: teql: Enforce hierarchy placement GangMin Kim <km.kim1503@gmail.com> managed to create a UAF on qfq by inserting teql as a child qdisc and exploiting a qlen sync issue. teql is not intended to be used as a child qdisc. Lets enforce that rule in patch #1. Although patch #1 fixes the issue, we prevent another potential qlen exploit in qfq in patch #2 by enforcing the child's active status is not determined by inspecting the qlen. In patch #3 we add a tdc test case. ==================== Link: https://patch.msgid.link/20260114160243.913069-1-jhs@mojatatu.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Jan 31, 2026
Patch series "mm/hugetlb: fixes for PMD table sharing (incl. using mmu_gather)", v3. One functional fix, one performance regression fix, and two related comment fixes. I cleaned up my prototype I recently shared [1] for the performance fix, deferring most of the cleanups I had in the prototype to a later point. While doing that I identified the other things. The goal of this patch set is to be backported to stable trees "fairly" easily. At least patch #1 and #4. Patch #1 fixes hugetlb_pmd_shared() not detecting any sharing Patch #2 + #3 are simple comment fixes that patch #4 interacts with. Patch #4 is a fix for the reported performance regression due to excessive IPI broadcasts during fork()+exit(). The last patch is all about TLB flushes, IPIs and mmu_gather. Read: complicated There are plenty of cleanups in the future to be had + one reasonable optimization on x86. But that's all out of scope for this series. Runtime tested, with a focus on fixing the performance regression using the original reproducer [2] on x86. This patch (of 4): We switched from (wrongly) using the page count to an independent shared count. Now, shared page tables have a refcount of 1 (excluding speculative references) and instead use ptdesc->pt_share_count to identify sharing. We didn't convert hugetlb_pmd_shared(), so right now, we would never detect a shared PMD table as such, because sharing/unsharing no longer touches the refcount of a PMD table. Page migration, like mbind() or migrate_pages() would allow for migrating folios mapped into such shared PMD tables, even though the folios are not exclusive. In smaps we would account them as "private" although they are "shared", and we would be wrongly setting the PM_MMAP_EXCLUSIVE in the pagemap interface. Fix it by properly using ptdesc_pmd_is_shared() in hugetlb_pmd_shared(). Link: https://lkml.kernel.org/r/20251223214037.580860-1-david@kernel.org Link: https://lkml.kernel.org/r/20251223214037.580860-2-david@kernel.org Link: https://lore.kernel.org/all/8cab934d-4a56-44aa-b641-bfd7e23bd673@kernel.org/ [1] Link: https://lore.kernel.org/all/8cab934d-4a56-44aa-b641-bfd7e23bd673@kernel.org/ [2] Fixes: 59d9094 ("mm: hugetlb: independent PMD page table shared count") Signed-off-by: David Hildenbrand (Red Hat) <david@kernel.org> Reviewed-by: Rik van Riel <riel@surriel.com> Reviewed-by: Lance Yang <lance.yang@linux.dev> Tested-by: Lance Yang <lance.yang@linux.dev> Reviewed-by: Harry Yoo <harry.yoo@oracle.com> Tested-by: Laurence Oberman <loberman@redhat.com> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Acked-by: Oscar Salvador <osalvador@suse.de> Cc: Liu Shixin <liushixin2@huawei.com> Cc: Uschakow, Stanislav" <suschako@amazon.de> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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…itives The "valid" readout delay between the two reads of the watchdog is larger than the valid delta between the resulting watchdog and clocksource intervals, which results in false positive watchdog results. Assume TSC is the clocksource and HPET is the watchdog and both have a uncertainty margin of 250us (default). The watchdog readout does: 1) wdnow = read(HPET); 2) csnow = read(TSC); 3) wdend = read(HPET); The valid window for the delta between #1 and #3 is calculated by the uncertainty margins of the watchdog and the clocksource: m = 2 * watchdog.uncertainty_margin + cs.uncertainty margin; which results in 750us for the TSC/HPET case. The actual interval comparison uses a smaller margin: m = watchdog.uncertainty_margin + cs.uncertainty margin; which results in 500us for the TSC/HPET case. That means the following scenario will trigger the watchdog: Watchdog cycle N: 1) wdnow[N] = read(HPET); 2) csnow[N] = read(TSC); 3) wdend[N] = read(HPET); Assume the delay between #1 and #2 is 100us and the delay between #1 and Watchdog cycle N + 1: 4) wdnow[N + 1] = read(HPET); 5) csnow[N + 1] = read(TSC); 6) wdend[N + 1] = read(HPET); If the delay between #4 and #6 is within the 750us margin then any delay between #4 and #5 which is larger than 600us will fail the interval check and mark the TSC unstable because the intervals are calculated against the previous value: wd_int = wdnow[N + 1] - wdnow[N]; cs_int = csnow[N + 1] - csnow[N]; Putting the above delays in place this results in: cs_int = (wdnow[N + 1] + 610us) - (wdnow[N] + 100us); -> cs_int = wd_int + 510us; which is obviously larger than the allowed 500us margin and results in marking TSC unstable. Fix this by using the same margin as the interval comparison. If the delay between two watchdog reads is larger than that, then the readout was either disturbed by interconnect congestion, NMIs or SMIs. Fixes: 4ac1dd3 ("clocksource: Set cs_watchdog_read() checks based on .uncertainty_margin") Reported-by: Daniel J Blueman <daniel@quora.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Paul E. McKenney <paulmck@kernel.org> Tested-by: Paul E. McKenney <paulmck@kernel.org> Link: https://lore.kernel.org/lkml/20250602223251.496591-1-daniel@quora.org/ Link: https://patch.msgid.link/87bjjxc9dq.ffs@tglx
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…alled from deferred_grow_zone() Commit 3acb913 ("mm/mm_init: use deferred_init_memmap_chunk() in deferred_grow_zone()") made deferred_grow_zone() call deferred_init_memmap_chunk() within a pgdat_resize_lock() critical section with irqs disabled. It did check for irqs_disabled() in deferred_init_memmap_chunk() to avoid calling cond_resched(). For a PREEMPT_RT kernel build, however, spin_lock_irqsave() does not disable interrupt but rcu_read_lock() is called. This leads to the following bug report. BUG: sleeping function called from invalid context at mm/mm_init.c:2091 in_atomic(): 0, irqs_disabled(): 0, non_block: 0, pid: 1, name: swapper/0 preempt_count: 0, expected: 0 RCU nest depth: 1, expected: 0 3 locks held by swapper/0/1: #0: ffff80008471b7a0 (sched_domains_mutex){+.+.}-{4:4}, at: sched_domains_mutex_lock+0x28/0x40 #1: ffff003bdfffef48 (&pgdat->node_size_lock){+.+.}-{3:3}, at: deferred_grow_zone+0x140/0x278 #2: ffff800084acf600 (rcu_read_lock){....}-{1:3}, at: rt_spin_lock+0x1b4/0x408 CPU: 0 UID: 0 PID: 1 Comm: swapper/0 Tainted: G W 6.19.0-rc6-test #1 PREEMPT_{RT,(full) } Tainted: [W]=WARN Call trace: show_stack+0x20/0x38 (C) dump_stack_lvl+0xdc/0xf8 dump_stack+0x1c/0x28 __might_resched+0x384/0x530 deferred_init_memmap_chunk+0x560/0x688 deferred_grow_zone+0x190/0x278 _deferred_grow_zone+0x18/0x30 get_page_from_freelist+0x780/0xf78 __alloc_frozen_pages_noprof+0x1dc/0x348 alloc_slab_page+0x30/0x110 allocate_slab+0x98/0x2a0 new_slab+0x4c/0x80 ___slab_alloc+0x5a4/0x770 __slab_alloc.constprop.0+0x88/0x1e0 __kmalloc_node_noprof+0x2c0/0x598 __sdt_alloc+0x3b8/0x728 build_sched_domains+0xe0/0x1260 sched_init_domains+0x14c/0x1c8 sched_init_smp+0x9c/0x1d0 kernel_init_freeable+0x218/0x358 kernel_init+0x28/0x208 ret_from_fork+0x10/0x20 Fix it adding a new argument to deferred_init_memmap_chunk() to explicitly tell it if cond_resched() is allowed or not instead of relying on some current state information which may vary depending on the exact kernel configuration options that are enabled. Link: https://lkml.kernel.org/r/20260122184343.546627-1-longman@redhat.com Fixes: 3acb913 ("mm/mm_init: use deferred_init_memmap_chunk() in deferred_grow_zone()") Signed-off-by: Waiman Long <longman@redhat.com> Suggested-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Cc: David Hildenbrand <david@kernel.org> Cc: "Paul E . McKenney" <paulmck@kernel.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Wei Yang <richard.weiyang@gmail.com> Cc: <stable@vger.kernrl.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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There was a lockdep warning in sprd_gpio: [ 6.258269][T329@C6] [ BUG: Invalid wait context ] [ 6.258270][T329@C6] 6.18.0-android17-0-g30527ad7aaae-ab00009-4k #1 Tainted: G W OE [ 6.258272][T329@C6] ----------------------------- [ 6.258273][T329@C6] modprobe/329 is trying to lock: [ 6.258275][T329@C6] ffffff8081c91690 (&sprd_gpio->lock){....}-{3:3}, at: sprd_gpio_irq_unmask+0x4c/0xa4 [gpio_sprd] [ 6.258282][T329@C6] other info that might help us debug this: [ 6.258283][T329@C6] context-{5:5} [ 6.258285][T329@C6] 3 locks held by modprobe/329: [ 6.258286][T329@C6] #0: ffffff808baca108 (&dev->mutex){....}-{4:4}, at: __driver_attach+0xc4/0x204 [ 6.258295][T329@C6] #1: ffffff80965e7240 (request_class#4){+.+.}-{4:4}, at: __setup_irq+0x1cc/0x82c [ 6.258304][T329@C6] #2: ffffff80965e70c8 (lock_class#4){....}-{2:2}, at: __setup_irq+0x21c/0x82c [ 6.258313][T329@C6] stack backtrace: [ 6.258314][T329@C6] CPU: 6 UID: 0 PID: 329 Comm: modprobe Tainted: G W OE 6.18.0-android17-0-g30527ad7aaae-ab00009-4k #1 PREEMPT 3ad5b0f45741a16e5838da790706e16ceb6717df [ 6.258316][T329@C6] Tainted: [W]=WARN, [O]=OOT_MODULE, [E]=UNSIGNED_MODULE [ 6.258317][T329@C6] Hardware name: Unisoc UMS9632-base Board (DT) [ 6.258318][T329@C6] Call trace: [ 6.258318][T329@C6] show_stack+0x20/0x30 (C) [ 6.258321][T329@C6] __dump_stack+0x28/0x3c [ 6.258324][T329@C6] dump_stack_lvl+0xac/0xf0 [ 6.258326][T329@C6] dump_stack+0x18/0x3c [ 6.258329][T329@C6] __lock_acquire+0x824/0x2c28 [ 6.258331][T329@C6] lock_acquire+0x148/0x2cc [ 6.258333][T329@C6] _raw_spin_lock_irqsave+0x6c/0xb4 [ 6.258334][T329@C6] sprd_gpio_irq_unmask+0x4c/0xa4 [gpio_sprd 814535e93c6d8e0853c45c02eab0fa88a9da6487] [ 6.258337][T329@C6] irq_startup+0x238/0x350 [ 6.258340][T329@C6] __setup_irq+0x504/0x82c [ 6.258342][T329@C6] request_threaded_irq+0x118/0x184 [ 6.258344][T329@C6] devm_request_threaded_irq+0x94/0x120 [ 6.258347][T329@C6] sc8546_init_irq+0x114/0x170 [sc8546_charger 223586ccafc27439f7db4f95b0c8e6e882349a99] [ 6.258352][T329@C6] sc8546_charger_probe+0x53c/0x5a0 [sc8546_charger 223586ccafc27439f7db4f95b0c8e6e882349a99] [ 6.258358][T329@C6] i2c_device_probe+0x2c8/0x350 [ 6.258361][T329@C6] really_probe+0x1a8/0x46c [ 6.258363][T329@C6] __driver_probe_device+0xa4/0x10c [ 6.258366][T329@C6] driver_probe_device+0x44/0x1b4 [ 6.258369][T329@C6] __driver_attach+0xd0/0x204 [ 6.258371][T329@C6] bus_for_each_dev+0x10c/0x168 [ 6.258373][T329@C6] driver_attach+0x2c/0x3c [ 6.258376][T329@C6] bus_add_driver+0x154/0x29c [ 6.258378][T329@C6] driver_register+0x70/0x10c [ 6.258381][T329@C6] i2c_register_driver+0x48/0xc8 [ 6.258384][T329@C6] init_module+0x28/0xfd8 [sc8546_charger 223586ccafc27439f7db4f95b0c8e6e882349a99] [ 6.258389][T329@C6] do_one_initcall+0x128/0x42c [ 6.258392][T329@C6] do_init_module+0x60/0x254 [ 6.258395][T329@C6] load_module+0x1054/0x1220 [ 6.258397][T329@C6] __arm64_sys_finit_module+0x240/0x35c [ 6.258400][T329@C6] invoke_syscall+0x60/0xec [ 6.258402][T329@C6] el0_svc_common+0xb0/0xe4 [ 6.258405][T329@C6] do_el0_svc+0x24/0x30 [ 6.258407][T329@C6] el0_svc+0x54/0x1c4 [ 6.258409][T329@C6] el0t_64_sync_handler+0x68/0xdc [ 6.258411][T329@C6] el0t_64_sync+0x1c4/0x1c8 This is because the spin_lock would change to rt_mutex in PREEMPT_RT, however the sprd_gpio->lock would use in hard-irq, this is unsafe. So change the spin_lock_t to raw_spin_lock_t to use the spinlock in hard-irq. Signed-off-by: Xuewen Yan <xuewen.yan@unisoc.com> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com> Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Link: https://lore.kernel.org/r/20260126094209.9855-1-xuewen.yan@unisoc.com [Bartosz: tweaked the commit message] Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
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Since the commit 25c6a5a ("net: phy: micrel: Dynamically control external clock of KSZ PHY"), the clock of Micrel PHY has been enabled by phy_driver::resume() and disabled by phy_driver::suspend(). However, devm_clk_get_optional_enabled() is used in kszphy_probe(), so the clock will automatically be disabled when the device is unbound from the bus. Therefore, this could cause the clock to be disabled twice, resulting in clk driver warnings. For example, this issue can be reproduced on i.MX6ULL platform, and we can see the following logs when removing the FEC MAC drivers. $ echo 2188000.ethernet > /sys/bus/platform/drivers/fec/unbind $ echo 20b4000.ethernet > /sys/bus/platform/drivers/fec/unbind [ 109.758207] ------------[ cut here ]------------ [ 109.758240] WARNING: drivers/clk/clk.c:1188 at clk_core_disable+0xb4/0xd0, CPU#0: sh/639 [ 109.771011] enet2_ref already disabled [ 109.793359] Call trace: [ 109.822006] clk_core_disable from clk_disable+0x28/0x34 [ 109.827340] clk_disable from clk_disable_unprepare+0xc/0x18 [ 109.833029] clk_disable_unprepare from devm_clk_release+0x1c/0x28 [ 109.839241] devm_clk_release from devres_release_all+0x98/0x100 [ 109.845278] devres_release_all from device_unbind_cleanup+0xc/0x70 [ 109.851571] device_unbind_cleanup from device_release_driver_internal+0x1a4/0x1f4 [ 109.859170] device_release_driver_internal from bus_remove_device+0xbc/0xe4 [ 109.866243] bus_remove_device from device_del+0x140/0x458 [ 109.871757] device_del from phy_mdio_device_remove+0xc/0x24 [ 109.877452] phy_mdio_device_remove from mdiobus_unregister+0x40/0xac [ 109.883918] mdiobus_unregister from fec_enet_mii_remove+0x40/0x78 [ 109.890125] fec_enet_mii_remove from fec_drv_remove+0x4c/0x158 [ 109.896076] fec_drv_remove from device_release_driver_internal+0x17c/0x1f4 [ 109.962748] WARNING: drivers/clk/clk.c:1047 at clk_core_unprepare+0xfc/0x13c, CPU#0: sh/639 [ 109.975805] enet2_ref already unprepared [ 110.002866] Call trace: [ 110.031758] clk_core_unprepare from clk_unprepare+0x24/0x2c [ 110.037440] clk_unprepare from devm_clk_release+0x1c/0x28 [ 110.042957] devm_clk_release from devres_release_all+0x98/0x100 [ 110.048989] devres_release_all from device_unbind_cleanup+0xc/0x70 [ 110.055280] device_unbind_cleanup from device_release_driver_internal+0x1a4/0x1f4 [ 110.062877] device_release_driver_internal from bus_remove_device+0xbc/0xe4 [ 110.069950] bus_remove_device from device_del+0x140/0x458 [ 110.075469] device_del from phy_mdio_device_remove+0xc/0x24 [ 110.081165] phy_mdio_device_remove from mdiobus_unregister+0x40/0xac [ 110.087632] mdiobus_unregister from fec_enet_mii_remove+0x40/0x78 [ 110.093836] fec_enet_mii_remove from fec_drv_remove+0x4c/0x158 [ 110.099782] fec_drv_remove from device_release_driver_internal+0x17c/0x1f4 After analyzing the process of removing the FEC driver, as shown below, it can be seen that the clock was disabled twice by the PHY driver. fec_drv_remove() --> fec_enet_close() --> phy_stop() --> phy_suspend() --> kszphy_suspend() #1 The clock is disabled --> fec_enet_mii_remove() --> mdiobus_unregister() --> phy_mdio_device_remove() --> device_del() --> devm_clk_release() #2 The clock is disabled again Therefore, devm_clk_get_optional() is used to fix the above issue. And to avoid the issue mentioned by the commit 9853294 ("net: phy: micrel: use devm_clk_get_optional_enabled for the rmii-ref clock"), the clock is enabled by clk_prepare_enable() to get the correct clock rate. Fixes: 25c6a5a ("net: phy: micrel: Dynamically control external clock of KSZ PHY") Signed-off-by: Wei Fang <wei.fang@nxp.com> Reviewed-by: Maxime Chevallier <maxime.chevallier@bootlin.com> Link: https://patch.msgid.link/20260126081544.983517-1-wei.fang@nxp.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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In ath12k_mac_op_link_sta_statistics(), the atomic context scope introduced by dp_lock also covers firmware stats request. Since that request could block, below issue is hit: BUG: sleeping function called from invalid context at kernel/locking/mutex.c:575 in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 6866, name: iw preempt_count: 201, expected: 0 RCU nest depth: 0, expected: 0 3 locks held by iw/6866: #0:[...] qualcomm-linux#1:[...] qualcomm-linux#2: ffff9748f43230c8 (&dp->dp_lock){+.-.}-{3:3}, at: ath12k_mac_op_link_sta_statistics+0xc6/0x380 [ath12k] Preemption disabled at: [<ffffffffc0349656>] ath12k_mac_op_link_sta_statistics+0xc6/0x380 [ath12k] Call Trace: <TASK> show_stack dump_stack_lvl dump_stack __might_resched.cold __might_sleep __mutex_lock mutex_lock_nested ath12k_mac_get_fw_stats ath12k_mac_op_link_sta_statistics </TASK> Since firmware stats request doesn't require protection from dp_lock, move it outside to fix this issue. While moving, also refine that code hunk to make function parameters get populated when really necessary. Tested-on: WCN7850 hw2.0 PCI WLAN.HMT.1.1.c5-00302-QCAHMTSWPL_V1.0_V2.0_SILICONZ-1.115823.3 Signed-off-by: Baochen Qiang <baochen.qiang@oss.qualcomm.com> Reviewed-by: Vasanthakumar Thiagarajan <vasanthakumar.thiagarajan@oss.qualcomm.com> Link: https://patch.msgid.link/20251119-ath12k-ng-sleep-in-atomic-v1-1-5d1a726597db@oss.qualcomm.com Signed-off-by: Jeff Johnson <jeff.johnson@oss.qualcomm.com>
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In ath12k_mac_op_link_sta_statistics(), the atomic context scope introduced by dp_lock also covers firmware stats request. Since that request could block, below issue is hit: BUG: sleeping function called from invalid context at kernel/locking/mutex.c:575 in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 6866, name: iw preempt_count: 201, expected: 0 RCU nest depth: 0, expected: 0 3 locks held by iw/6866: #0:[...] qualcomm-linux#1:[...] qualcomm-linux#2: ffff9748f43230c8 (&dp->dp_lock){+.-.}-{3:3}, at: ath12k_mac_op_link_sta_statistics+0xc6/0x380 [ath12k] Preemption disabled at: [<ffffffffc0349656>] ath12k_mac_op_link_sta_statistics+0xc6/0x380 [ath12k] Call Trace: <TASK> show_stack dump_stack_lvl dump_stack __might_resched.cold __might_sleep __mutex_lock mutex_lock_nested ath12k_mac_get_fw_stats ath12k_mac_op_link_sta_statistics </TASK> Since firmware stats request doesn't require protection from dp_lock, move it outside to fix this issue. While moving, also refine that code hunk to make function parameters get populated when really necessary. Tested-on: WCN7850 hw2.0 PCI WLAN.HMT.1.1.c5-00302-QCAHMTSWPL_V1.0_V2.0_SILICONZ-1.115823.3 Signed-off-by: Baochen Qiang <baochen.qiang@oss.qualcomm.com> Reviewed-by: Vasanthakumar Thiagarajan <vasanthakumar.thiagarajan@oss.qualcomm.com> Link: https://patch.msgid.link/20251119-ath12k-ng-sleep-in-atomic-v1-1-5d1a726597db@oss.qualcomm.com Signed-off-by: Jeff Johnson <jeff.johnson@oss.qualcomm.com>
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In ath12k_mac_op_link_sta_statistics(), the atomic context scope introduced by dp_lock also covers firmware stats request. Since that request could block, below issue is hit: BUG: sleeping function called from invalid context at kernel/locking/mutex.c:575 in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 6866, name: iw preempt_count: 201, expected: 0 RCU nest depth: 0, expected: 0 3 locks held by iw/6866: #0:[...] #1:[...] #2: ffff9748f43230c8 (&dp->dp_lock){+.-.}-{3:3}, at: ath12k_mac_op_link_sta_statistics+0xc6/0x380 [ath12k] Preemption disabled at: [<ffffffffc0349656>] ath12k_mac_op_link_sta_statistics+0xc6/0x380 [ath12k] Call Trace: <TASK> show_stack dump_stack_lvl dump_stack __might_resched.cold __might_sleep __mutex_lock mutex_lock_nested ath12k_mac_get_fw_stats ath12k_mac_op_link_sta_statistics </TASK> Since firmware stats request doesn't require protection from dp_lock, move it outside to fix this issue. While moving, also refine that code hunk to make function parameters get populated when really necessary. Tested-on: WCN7850 hw2.0 PCI WLAN.HMT.1.1.c5-00302-QCAHMTSWPL_V1.0_V2.0_SILICONZ-1.115823.3 Signed-off-by: Baochen Qiang <baochen.qiang@oss.qualcomm.com> Reviewed-by: Vasanthakumar Thiagarajan <vasanthakumar.thiagarajan@oss.qualcomm.com> Link: https://patch.msgid.link/20251119-ath12k-ng-sleep-in-atomic-v1-1-5d1a726597db@oss.qualcomm.com Signed-off-by: Jeff Johnson <jeff.johnson@oss.qualcomm.com>
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Feb 17, 2026
Patch series "mm/hugetlb: fixes for PMD table sharing (incl. using mmu_gather)", v3. One functional fix, one performance regression fix, and two related comment fixes. I cleaned up my prototype I recently shared [1] for the performance fix, deferring most of the cleanups I had in the prototype to a later point. While doing that I identified the other things. The goal of this patch set is to be backported to stable trees "fairly" easily. At least patch #1 and #4. Patch #1 fixes hugetlb_pmd_shared() not detecting any sharing Patch #2 + #3 are simple comment fixes that patch #4 interacts with. Patch #4 is a fix for the reported performance regression due to excessive IPI broadcasts during fork()+exit(). The last patch is all about TLB flushes, IPIs and mmu_gather. Read: complicated There are plenty of cleanups in the future to be had + one reasonable optimization on x86. But that's all out of scope for this series. Runtime tested, with a focus on fixing the performance regression using the original reproducer [2] on x86. This patch (of 4): We switched from (wrongly) using the page count to an independent shared count. Now, shared page tables have a refcount of 1 (excluding speculative references) and instead use ptdesc->pt_share_count to identify sharing. We didn't convert hugetlb_pmd_shared(), so right now, we would never detect a shared PMD table as such, because sharing/unsharing no longer touches the refcount of a PMD table. Page migration, like mbind() or migrate_pages() would allow for migrating folios mapped into such shared PMD tables, even though the folios are not exclusive. In smaps we would account them as "private" although they are "shared", and we would be wrongly setting the PM_MMAP_EXCLUSIVE in the pagemap interface. Fix it by properly using ptdesc_pmd_is_shared() in hugetlb_pmd_shared(). Link: https://lkml.kernel.org/r/20251223214037.580860-1-david@kernel.org Link: https://lkml.kernel.org/r/20251223214037.580860-2-david@kernel.org Link: https://lore.kernel.org/all/8cab934d-4a56-44aa-b641-bfd7e23bd673@kernel.org/ [1] Link: https://lore.kernel.org/all/8cab934d-4a56-44aa-b641-bfd7e23bd673@kernel.org/ [2] Fixes: 59d9094 ("mm: hugetlb: independent PMD page table shared count") Signed-off-by: David Hildenbrand (Red Hat) <david@kernel.org> Reviewed-by: Rik van Riel <riel@surriel.com> Reviewed-by: Lance Yang <lance.yang@linux.dev> Tested-by: Lance Yang <lance.yang@linux.dev> Reviewed-by: Harry Yoo <harry.yoo@oracle.com> Tested-by: Laurence Oberman <loberman@redhat.com> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Acked-by: Oscar Salvador <osalvador@suse.de> Cc: Liu Shixin <liushixin2@huawei.com> Cc: Uschakow, Stanislav" <suschako@amazon.de> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
abelvesa
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Patch series "kallsyms: Prevent invalid access when showing module
buildid", v3.
We have seen nested crashes in __sprint_symbol(), see below. They seem to
be caused by an invalid pointer to "buildid". This patchset cleans up
kallsyms code related to module buildid and fixes this invalid access when
printing backtraces.
I made an audit of __sprint_symbol() and found several situations
when the buildid might be wrong:
+ bpf_address_lookup() does not set @modbuildid
+ ftrace_mod_address_lookup() does not set @modbuildid
+ __sprint_symbol() does not take rcu_read_lock and
the related struct module might get removed before
mod->build_id is printed.
This patchset solves these problems:
+ 1st, 2nd patches are preparatory
+ 3rd, 4th, 6th patches fix the above problems
+ 5th patch cleans up a suspicious initialization code.
This is the backtrace, we have seen. But it is not really important.
The problems fixed by the patchset are obvious:
crash64> bt [62/2029]
PID: 136151 TASK: ffff9f6c981d4000 CPU: 367 COMMAND: "btrfs"
#0 [ffffbdb687635c28] machine_kexec at ffffffffb4c845b3
#1 [ffffbdb687635c80] __crash_kexec at ffffffffb4d86a6a
#2 [ffffbdb687635d08] hex_string at ffffffffb51b3b61
#3 [ffffbdb687635d40] crash_kexec at ffffffffb4d87964
#4 [ffffbdb687635d50] oops_end at ffffffffb4c41fc8
#5 [ffffbdb687635d70] do_trap at ffffffffb4c3e49a
#6 [ffffbdb687635db8] do_error_trap at ffffffffb4c3e6a4
#7 [ffffbdb687635df8] exc_stack_segment at ffffffffb5666b33
#8 [ffffbdb687635e20] asm_exc_stack_segment at ffffffffb5800cf9
...
This patch (of 7)
The function kallsyms_lookup_buildid() initializes the given @namebuf by
clearing the first and the last byte. It is not clear why.
The 1st byte makes sense because some callers ignore the return code and
expect that the buffer contains a valid string, for example:
- function_stat_show()
- kallsyms_lookup()
- kallsyms_lookup_buildid()
The initialization of the last byte does not make much sense because it
can later be overwritten. Fortunately, it seems that all called functions
behave correctly:
- kallsyms_expand_symbol() explicitly adds the trailing '\0'
at the end of the function.
- All *__address_lookup() functions either use the safe strscpy()
or they do not touch the buffer at all.
Document the reason for clearing the first byte. And remove the useless
initialization of the last byte.
Link: https://lkml.kernel.org/r/20251128135920.217303-2-pmladek@suse.com
Signed-off-by: Petr Mladek <pmladek@suse.com>
Reviewed-by: Aaron Tomlin <atomlin@atomlin.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkman <daniel@iogearbox.net>
Cc: John Fastabend <john.fastabend@gmail.com>
Cc: Kees Cook <kees@kernel.org>
Cc: Luis Chamberalin <mcgrof@kernel.org>
Cc: Marc Rutland <mark.rutland@arm.com>
Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org>
Cc: Petr Pavlu <petr.pavlu@suse.com>
Cc: Sami Tolvanen <samitolvanen@google.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Daniel Gomez <da.gomez@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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…ked_inode() In btrfs_read_locked_inode() we are calling btrfs_init_file_extent_tree() while holding a path with a read locked leaf from a subvolume tree, and btrfs_init_file_extent_tree() may do a GFP_KERNEL allocation, which can trigger reclaim. This can create a circular lock dependency which lockdep warns about with the following splat: [6.1433] ====================================================== [6.1574] WARNING: possible circular locking dependency detected [6.1583] 6.18.0+ #4 Tainted: G U [6.1591] ------------------------------------------------------ [6.1599] kswapd0/117 is trying to acquire lock: [6.1606] ffff8d9b6333c5b8 (&delayed_node->mutex){+.+.}-{3:3}, at: __btrfs_release_delayed_node.part.0+0x39/0x2f0 [6.1625] but task is already holding lock: [6.1633] ffffffffa4ab8ce0 (fs_reclaim){+.+.}-{0:0}, at: balance_pgdat+0x195/0xc60 [6.1646] which lock already depends on the new lock. [6.1657] the existing dependency chain (in reverse order) is: [6.1667] -> #2 (fs_reclaim){+.+.}-{0:0}: [6.1677] fs_reclaim_acquire+0x9d/0xd0 [6.1685] __kmalloc_cache_noprof+0x59/0x750 [6.1694] btrfs_init_file_extent_tree+0x90/0x100 [6.1702] btrfs_read_locked_inode+0xc3/0x6b0 [6.1710] btrfs_iget+0xbb/0xf0 [6.1716] btrfs_lookup_dentry+0x3c5/0x8e0 [6.1724] btrfs_lookup+0x12/0x30 [6.1731] lookup_open.isra.0+0x1aa/0x6a0 [6.1739] path_openat+0x5f7/0xc60 [6.1746] do_filp_open+0xd6/0x180 [6.1753] do_sys_openat2+0x8b/0xe0 [6.1760] __x64_sys_openat+0x54/0xa0 [6.1768] do_syscall_64+0x97/0x3e0 [6.1776] entry_SYSCALL_64_after_hwframe+0x76/0x7e [6.1784] -> #1 (btrfs-tree-00){++++}-{3:3}: [6.1794] lock_release+0x127/0x2a0 [6.1801] up_read+0x1b/0x30 [6.1808] btrfs_search_slot+0x8e0/0xff0 [6.1817] btrfs_lookup_inode+0x52/0xd0 [6.1825] __btrfs_update_delayed_inode+0x73/0x520 [6.1833] btrfs_commit_inode_delayed_inode+0x11a/0x120 [6.1842] btrfs_log_inode+0x608/0x1aa0 [6.1849] btrfs_log_inode_parent+0x249/0xf80 [6.1857] btrfs_log_dentry_safe+0x3e/0x60 [6.1865] btrfs_sync_file+0x431/0x690 [6.1872] do_fsync+0x39/0x80 [6.1879] __x64_sys_fsync+0x13/0x20 [6.1887] do_syscall_64+0x97/0x3e0 [6.1894] entry_SYSCALL_64_after_hwframe+0x76/0x7e [6.1903] -> #0 (&delayed_node->mutex){+.+.}-{3:3}: [6.1913] __lock_acquire+0x15e9/0x2820 [6.1920] lock_acquire+0xc9/0x2d0 [6.1927] __mutex_lock+0xcc/0x10a0 [6.1934] __btrfs_release_delayed_node.part.0+0x39/0x2f0 [6.1944] btrfs_evict_inode+0x20b/0x4b0 [6.1952] evict+0x15a/0x2f0 [6.1958] prune_icache_sb+0x91/0xd0 [6.1966] super_cache_scan+0x150/0x1d0 [6.1974] do_shrink_slab+0x155/0x6f0 [6.1981] shrink_slab+0x48e/0x890 [6.1988] shrink_one+0x11a/0x1f0 [6.1995] shrink_node+0xbfd/0x1320 [6.1002] balance_pgdat+0x67f/0xc60 [6.1321] kswapd+0x1dc/0x3e0 [6.1643] kthread+0xff/0x240 [6.1965] ret_from_fork+0x223/0x280 [6.1287] ret_from_fork_asm+0x1a/0x30 [6.1616] other info that might help us debug this: [6.1561] Chain exists of: &delayed_node->mutex --> btrfs-tree-00 --> fs_reclaim [6.1503] Possible unsafe locking scenario: [6.1110] CPU0 CPU1 [6.1411] ---- ---- [6.1707] lock(fs_reclaim); [6.1998] lock(btrfs-tree-00); [6.1291] lock(fs_reclaim); [6.1581] lock(&delayed_node->mutex); [6.1874] *** DEADLOCK *** [6.1716] 2 locks held by kswapd0/117: [6.1999] #0: ffffffffa4ab8ce0 (fs_reclaim){+.+.}-{0:0}, at: balance_pgdat+0x195/0xc60 [6.1294] #1: ffff8d998344b0e0 (&type->s_umount_key#40){++++}- {3:3}, at: super_cache_scan+0x37/0x1d0 [6.1596] stack backtrace: [6.1183] CPU: 11 UID: 0 PID: 117 Comm: kswapd0 Tainted: G U 6.18.0+ #4 PREEMPT(lazy) [6.1185] Tainted: [U]=USER [6.1186] Hardware name: ASUS System Product Name/PRIME B560M-A AC, BIOS 2001 02/01/2023 [6.1187] Call Trace: [6.1187] <TASK> [6.1189] dump_stack_lvl+0x6e/0xa0 [6.1192] print_circular_bug.cold+0x17a/0x1c0 [6.1194] check_noncircular+0x175/0x190 [6.1197] __lock_acquire+0x15e9/0x2820 [6.1200] lock_acquire+0xc9/0x2d0 [6.1201] ? __btrfs_release_delayed_node.part.0+0x39/0x2f0 [6.1204] __mutex_lock+0xcc/0x10a0 [6.1206] ? __btrfs_release_delayed_node.part.0+0x39/0x2f0 [6.1208] ? __btrfs_release_delayed_node.part.0+0x39/0x2f0 [6.1211] ? __btrfs_release_delayed_node.part.0+0x39/0x2f0 [6.1213] __btrfs_release_delayed_node.part.0+0x39/0x2f0 [6.1215] btrfs_evict_inode+0x20b/0x4b0 [6.1217] ? lock_acquire+0xc9/0x2d0 [6.1220] evict+0x15a/0x2f0 [6.1222] prune_icache_sb+0x91/0xd0 [6.1224] super_cache_scan+0x150/0x1d0 [6.1226] do_shrink_slab+0x155/0x6f0 [6.1228] shrink_slab+0x48e/0x890 [6.1229] ? shrink_slab+0x2d2/0x890 [6.1231] shrink_one+0x11a/0x1f0 [6.1234] shrink_node+0xbfd/0x1320 [6.1236] ? shrink_node+0xa2d/0x1320 [6.1236] ? shrink_node+0xbd3/0x1320 [6.1239] ? balance_pgdat+0x67f/0xc60 [6.1239] balance_pgdat+0x67f/0xc60 [6.1241] ? finish_task_switch.isra.0+0xc4/0x2a0 [6.1246] kswapd+0x1dc/0x3e0 [6.1247] ? __pfx_autoremove_wake_function+0x10/0x10 [6.1249] ? __pfx_kswapd+0x10/0x10 [6.1250] kthread+0xff/0x240 [6.1251] ? __pfx_kthread+0x10/0x10 [6.1253] ret_from_fork+0x223/0x280 [6.1255] ? __pfx_kthread+0x10/0x10 [6.1257] ret_from_fork_asm+0x1a/0x30 [6.1260] </TASK> This is because: 1) The fsync task is holding an inode's delayed node mutex (for a directory) while calling __btrfs_update_delayed_inode() and that needs to do a search on the subvolume's btree (therefore read lock some extent buffers); 2) The lookup task, at btrfs_lookup(), triggered reclaim with the GFP_KERNEL allocation done by btrfs_init_file_extent_tree() while holding a read lock on a subvolume leaf; 3) The reclaim triggered kswapd which is doing inode eviction for the directory inode the fsync task is using as an argument to btrfs_commit_inode_delayed_inode() - but in that call chain we are trying to read lock the same leaf that the lookup task is holding while calling btrfs_init_file_extent_tree() and doing the GFP_KERNEL allocation. Fix this by calling btrfs_init_file_extent_tree() after we don't need the path anymore and release it in btrfs_read_locked_inode(). Reported-by: Thomas Hellström <thomas.hellstrom@linux.intel.com> Link: https://lore.kernel.org/linux-btrfs/6e55113a22347c3925458a5d840a18401a38b276.camel@linux.intel.com/ Fixes: 8679d26 ("btrfs: initialize inode::file_extent_tree after i_mode has been set") Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
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On the THUNDEROBOT ZERO laptop, the second NVMe slot and the discrete NVIDIA GPU are both controlled by power-resource PXP. Due to the SSDT table bug (lack of reference), PXP will be shut dow as an "unused" power resource during initialization, making the NVMe slot #2 + NVIDIA both inaccessible. This issue was introduced by commit a1224f3 ("ACPI: PM: Check states of power resources during initialization"). Here are test results on the three consecutive commits: (bad again!) a1224f3 ACPI: PM: Check states of power resources during initialization (good) bc28368 ACPI: PM: Do not turn off power resources in unknown state (bad) 519d819 Linux 5.15-rc6 On commit bc28368 ("ACPI: PM: Do not turn off power resources in unknown state") this was not an issue because the power resource state left UNKNOWN thus being ignored. See also commit 9b04d99 ("ACPI: PM: Do not turn of unused power resources on the Toshiba Click Mini") which is another almost identical case to this one. Fixes: a1224f3 ("ACPI: PM: Check states of power resources during initialization") Closes: https://bugzilla.kernel.org/show_bug.cgi?id=221087 Signed-off-by: Zhai Can <bczhc0@126.com> Link: https://patch.msgid.link/20260214161452.2849346-1-bczhc0@126.com Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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With PREEMPT_RT as potential configuration option, spinlock_t is now considered as a sleeping lock, and thus might cause issues when used in an atomic context. But even with PREEMPT_RT as potential configuration option, raw_spinlock_t remains as a true spinning lock/atomic context. This creates potential issues with the s390 debug/tracing feature. The functions to trace errors are called in various contexts, including under lock of raw_spinlock_t, and thus the used spinlock_t in each debug area is in violation of the locking semantics. Here are two examples involving failing PCI Read accesses that are traced while holding `pci_lock` in `drivers/pci/access.c`: ============================= [ BUG: Invalid wait context ] 6.19.0-devel #18 Not tainted ----------------------------- bash/3833 is trying to lock: 0000027790baee30 (&rc->lock){-.-.}-{3:3}, at: debug_event_common+0xfc/0x300 other info that might help us debug this: context-{5:5} 5 locks held by bash/3833: #0: 0000027efbb29450 (sb_writers#3){.+.+}-{0:0}, at: ksys_write+0x7c/0xf0 #1: 00000277f0504a90 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x13e/0x260 #2: 00000277beed8c18 (kn->active#339){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x164/0x260 #3: 00000277e9859190 (&dev->mutex){....}-{4:4}, at: pci_dev_lock+0x2e/0x40 #4: 00000383068a7708 (pci_lock){....}-{2:2}, at: pci_bus_read_config_dword+0x4a/0xb0 stack backtrace: CPU: 6 UID: 0 PID: 3833 Comm: bash Kdump: loaded Not tainted 6.19.0-devel #18 PREEMPTLAZY Hardware name: IBM 9175 ME1 701 (LPAR) Call Trace: [<00000383048afec2>] dump_stack_lvl+0xa2/0xe8 [<00000383049ba166>] __lock_acquire+0x816/0x1660 [<00000383049bb1fa>] lock_acquire+0x24a/0x370 [<00000383059e3860>] _raw_spin_lock_irqsave+0x70/0xc0 [<00000383048bbb6c>] debug_event_common+0xfc/0x300 [<0000038304900b0a>] __zpci_load+0x17a/0x1f0 [<00000383048fad88>] pci_read+0x88/0xd0 [<00000383054cbce0>] pci_bus_read_config_dword+0x70/0xb0 [<00000383054d55e4>] pci_dev_wait+0x174/0x290 [<00000383054d5a3e>] __pci_reset_function_locked+0xfe/0x170 [<00000383054d9b30>] pci_reset_function+0xd0/0x100 [<00000383054ee21a>] reset_store+0x5a/0x80 [<0000038304e98758>] kernfs_fop_write_iter+0x1e8/0x260 [<0000038304d995da>] new_sync_write+0x13a/0x180 [<0000038304d9c5d0>] vfs_write+0x200/0x330 [<0000038304d9c88c>] ksys_write+0x7c/0xf0 [<00000383059cfa80>] __do_syscall+0x210/0x500 [<00000383059e4c06>] system_call+0x6e/0x90 INFO: lockdep is turned off. ============================= [ BUG: Invalid wait context ] 6.19.0-devel #3 Not tainted ----------------------------- bash/6861 is trying to lock: 0000009da05c7430 (&rc->lock){-.-.}-{3:3}, at: debug_event_common+0xfc/0x300 other info that might help us debug this: context-{5:5} 5 locks held by bash/6861: #0: 000000acff404450 (sb_writers#3){.+.+}-{0:0}, at: ksys_write+0x7c/0xf0 #1: 000000acff41c490 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x13e/0x260 #2: 0000009da36937d8 (kn->active#75){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x164/0x260 #3: 0000009dd15250d0 (&zdev->state_lock){+.+.}-{4:4}, at: enable_slot+0x2e/0xc0 #4: 000001a19682f708 (pci_lock){....}-{2:2}, at: pci_bus_read_config_byte+0x42/0xa0 stack backtrace: CPU: 16 UID: 0 PID: 6861 Comm: bash Kdump: loaded Not tainted 6.19.0-devel #3 PREEMPTLAZY Hardware name: IBM 9175 ME1 701 (LPAR) Call Trace: [<000001a194837ec2>] dump_stack_lvl+0xa2/0xe8 [<000001a194942166>] __lock_acquire+0x816/0x1660 [<000001a1949431fa>] lock_acquire+0x24a/0x370 [<000001a19596b810>] _raw_spin_lock_irqsave+0x70/0xc0 [<000001a194843b6c>] debug_event_common+0xfc/0x300 [<000001a194888b0a>] __zpci_load+0x17a/0x1f0 [<000001a194882d88>] pci_read+0x88/0xd0 [<000001a195453b88>] pci_bus_read_config_byte+0x68/0xa0 [<000001a195457bc2>] pci_setup_device+0x62/0xad0 [<000001a195458e70>] pci_scan_single_device+0x90/0xe0 [<000001a19488a0f6>] zpci_bus_scan_device+0x46/0x80 [<000001a19547f958>] enable_slot+0x98/0xc0 [<000001a19547f134>] power_write_file+0xc4/0x110 [<000001a194e20758>] kernfs_fop_write_iter+0x1e8/0x260 [<000001a194d215da>] new_sync_write+0x13a/0x180 [<000001a194d245d0>] vfs_write+0x200/0x330 [<000001a194d2488c>] ksys_write+0x7c/0xf0 [<000001a195957a30>] __do_syscall+0x210/0x500 [<000001a19596cbb6>] system_call+0x6e/0x90 INFO: lockdep is turned off. Since it is desired to keep it possible to create trace records in most situations, including this particular case (failing PCI config space accesses are relevant), convert the used spinlock_t in `struct debug_info` to raw_spinlock_t. The impact is small, as the debug area lock only protects bounded memory access without external dependencies, apart from one function debug_set_size() where kfree() is implicitly called with the lock held. Move debug_info_free() out of this lock, to keep remove this external dependency. Acked-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Benjamin Block <bblock@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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The io_zcrx_put_niov_uref() function uses a non-atomic
check-then-decrement pattern (atomic_read followed by separate
atomic_dec) to manipulate user_refs. This is serialized against other
callers by rq_lock, but io_zcrx_scrub() modifies the same counter with
atomic_xchg() WITHOUT holding rq_lock.
On SMP systems, the following race exists:
CPU0 (refill, holds rq_lock) CPU1 (scrub, no rq_lock)
put_niov_uref:
atomic_read(uref) - 1
// window opens
atomic_xchg(uref, 0) - 1
return_niov_freelist(niov) [PUSH #1]
// window closes
atomic_dec(uref) - wraps to -1
returns true
return_niov(niov)
return_niov_freelist(niov) [PUSH #2: DOUBLE-FREE]
The same niov is pushed to the freelist twice, causing free_count to
exceed nr_iovs. Subsequent freelist pushes then perform an out-of-bounds
write (a u32 value) past the kvmalloc'd freelist array into the adjacent
slab object.
Fix this by replacing the non-atomic read-then-dec in
io_zcrx_put_niov_uref() with an atomic_try_cmpxchg loop that atomically
tests and decrements user_refs. This makes the operation safe against
concurrent atomic_xchg from scrub without requiring scrub to acquire
rq_lock.
Fixes: 34a3e60 ("io_uring/zcrx: implement zerocopy receive pp memory provider")
Cc: stable@vger.kernel.org
Signed-off-by: Kai Aizen <kai@snailsploit.com>
[pavel: removed a warning and a comment]
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Feb 23, 2026
The ALB RX path may access rx_hashtbl concurrently with bond teardown. During rapid bond up/down cycles, rlb_deinitialize() frees rx_hashtbl while RX handlers are still running, leading to a null pointer dereference detected by KASAN. However, the root cause is that rlb_arp_recv() can still be accessed after setting recv_probe to NULL, which is actually a use-after-free (UAF) issue. That is the reason for using the referenced commit in the Fixes tag. [ 214.174138] Oops: general protection fault, probably for non-canonical address 0xdffffc000000001d: 0000 [#1] SMP KASAN PTI [ 214.186478] KASAN: null-ptr-deref in range [0x00000000000000e8-0x00000000000000ef] [ 214.194933] CPU: 30 UID: 0 PID: 2375 Comm: ping Kdump: loaded Not tainted 6.19.0-rc8+ #2 PREEMPT(voluntary) [ 214.205907] Hardware name: Dell Inc. PowerEdge R730/0WCJNT, BIOS 2.14.0 01/14/2022 [ 214.214357] RIP: 0010:rlb_arp_recv+0x505/0xab0 [bonding] [ 214.220320] Code: 0f 85 2b 05 00 00 48 b8 00 00 00 00 00 fc ff df 40 0f b6 ed 48 c1 e5 06 49 03 ad 78 01 00 00 48 8d 7d 28 48 89 fa 48 c1 ea 03 <0f> b6 04 02 84 c0 74 06 0f 8e 12 05 00 00 80 7d 28 00 0f 84 8c 00 [ 214.241280] RSP: 0018:ffffc900073d8870 EFLAGS: 00010206 [ 214.247116] RAX: dffffc0000000000 RBX: ffff888168556822 RCX: ffff88816855681e [ 214.255082] RDX: 000000000000001d RSI: dffffc0000000000 RDI: 00000000000000e8 [ 214.263048] RBP: 00000000000000c0 R08: 0000000000000002 R09: ffffed11192021c8 [ 214.271013] R10: ffff8888c9010e43 R11: 0000000000000001 R12: 1ffff92000e7b119 [ 214.278978] R13: ffff8888c9010e00 R14: ffff888168556822 R15: ffff888168556810 [ 214.286943] FS: 00007f85d2d9cb80(0000) GS:ffff88886ccb3000(0000) knlGS:0000000000000000 [ 214.295966] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 214.302380] CR2: 00007f0d047b5e34 CR3: 00000008a1c2e002 CR4: 00000000001726f0 [ 214.310347] Call Trace: [ 214.313070] <IRQ> [ 214.315318] ? __pfx_rlb_arp_recv+0x10/0x10 [bonding] [ 214.320975] bond_handle_frame+0x166/0xb60 [bonding] [ 214.326537] ? __pfx_bond_handle_frame+0x10/0x10 [bonding] [ 214.332680] __netif_receive_skb_core.constprop.0+0x576/0x2710 [ 214.339199] ? __pfx_arp_process+0x10/0x10 [ 214.343775] ? sched_balance_find_src_group+0x98/0x630 [ 214.349513] ? __pfx___netif_receive_skb_core.constprop.0+0x10/0x10 [ 214.356513] ? arp_rcv+0x307/0x690 [ 214.360311] ? __pfx_arp_rcv+0x10/0x10 [ 214.364499] ? __lock_acquire+0x58c/0xbd0 [ 214.368975] __netif_receive_skb_one_core+0xae/0x1b0 [ 214.374518] ? __pfx___netif_receive_skb_one_core+0x10/0x10 [ 214.380743] ? lock_acquire+0x10b/0x140 [ 214.385026] process_backlog+0x3f1/0x13a0 [ 214.389502] ? process_backlog+0x3aa/0x13a0 [ 214.394174] __napi_poll.constprop.0+0x9f/0x370 [ 214.399233] net_rx_action+0x8c1/0xe60 [ 214.403423] ? __pfx_net_rx_action+0x10/0x10 [ 214.408193] ? lock_acquire.part.0+0xbd/0x260 [ 214.413058] ? sched_clock_cpu+0x6c/0x540 [ 214.417540] ? mark_held_locks+0x40/0x70 [ 214.421920] handle_softirqs+0x1fd/0x860 [ 214.426302] ? __pfx_handle_softirqs+0x10/0x10 [ 214.431264] ? __neigh_event_send+0x2d6/0xf50 [ 214.436131] do_softirq+0xb1/0xf0 [ 214.439830] </IRQ> The issue is reproducible by repeatedly running ip link set bond0 up/down while receiving ARP messages, where rlb_arp_recv() can race with rlb_deinitialize() and dereference a freed rx_hashtbl entry. Fix this by setting recv_probe to NULL and then calling synchronize_net() to wait for any concurrent RX processing to finish. This ensures that no RX handler can access rx_hashtbl after it is freed in bond_alb_deinitialize(). Reported-by: Liang Li <liali@redhat.com> Fixes: 3aba891 ("bonding: move processing of recv handlers into handle_frame()") Reviewed-by: Nikolay Aleksandrov <nikolay@nvidia.com> Acked-by: Jay Vosburgh <jv@jvosburgh.net> Signed-off-by: Hangbin Liu <liuhangbin@gmail.com> Link: https://patch.msgid.link/20260218060919.101574-1-liuhangbin@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
krishnachaitanya-linux
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Feb 24, 2026
Jakub reported an MPTCP deadlock at fallback time: WARNING: possible recursive locking detected 6.18.0-rc7-virtme #1 Not tainted -------------------------------------------- mptcp_connect/20858 is trying to acquire lock: ff1100001da18b60 (&msk->fallback_lock){+.-.}-{3:3}, at: __mptcp_try_fallback+0xd8/0x280 but task is already holding lock: ff1100001da18b60 (&msk->fallback_lock){+.-.}-{3:3}, at: __mptcp_retrans+0x352/0xaa0 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&msk->fallback_lock); lock(&msk->fallback_lock); *** DEADLOCK *** May be due to missing lock nesting notation 3 locks held by mptcp_connect/20858: #0: ff1100001da18290 (sk_lock-AF_INET){+.+.}-{0:0}, at: mptcp_sendmsg+0x114/0x1bc0 #1: ff1100001db40fd0 (k-sk_lock-AF_INET#2){+.+.}-{0:0}, at: __mptcp_retrans+0x2cb/0xaa0 #2: ff1100001da18b60 (&msk->fallback_lock){+.-.}-{3:3}, at: __mptcp_retrans+0x352/0xaa0 stack backtrace: CPU: 0 UID: 0 PID: 20858 Comm: mptcp_connect Not tainted 6.18.0-rc7-virtme #1 PREEMPT(full) Hardware name: Bochs, BIOS Bochs 01/01/2011 Call Trace: <TASK> dump_stack_lvl+0x6f/0xa0 print_deadlock_bug.cold+0xc0/0xcd validate_chain+0x2ff/0x5f0 __lock_acquire+0x34c/0x740 lock_acquire.part.0+0xbc/0x260 _raw_spin_lock_bh+0x38/0x50 __mptcp_try_fallback+0xd8/0x280 mptcp_sendmsg_frag+0x16c2/0x3050 __mptcp_retrans+0x421/0xaa0 mptcp_release_cb+0x5aa/0xa70 release_sock+0xab/0x1d0 mptcp_sendmsg+0xd5b/0x1bc0 sock_write_iter+0x281/0x4d0 new_sync_write+0x3c5/0x6f0 vfs_write+0x65e/0xbb0 ksys_write+0x17e/0x200 do_syscall_64+0xbb/0xfd0 entry_SYSCALL_64_after_hwframe+0x4b/0x53 RIP: 0033:0x7fa5627cbc5e Code: 4d 89 d8 e8 14 bd 00 00 4c 8b 5d f8 41 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 11 c9 c3 0f 1f 80 00 00 00 00 48 8b 45 10 0f 05 <c9> c3 83 e2 39 83 fa 08 75 e7 e8 13 ff ff ff 0f 1f 00 f3 0f 1e fa RSP: 002b:00007fff1fe14700 EFLAGS: 00000202 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 00007fa5627cbc5e RDX: 0000000000001f9c RSI: 00007fff1fe16984 RDI: 0000000000000005 RBP: 00007fff1fe14710 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 00007fff1fe16920 R13: 0000000000002000 R14: 0000000000001f9c R15: 0000000000001f9c The packet scheduler could attempt a reinjection after receiving an MP_FAIL and before the infinite map has been transmitted, causing a deadlock since MPTCP needs to do the reinjection atomically from WRT fallback. Address the issue explicitly avoiding the reinjection in the critical scenario. Note that this is the only fallback critical section that could potentially send packets and hit the double-lock. Reported-by: Jakub Kicinski <kuba@kernel.org> Closes: https://netdev-ctrl.bots.linux.dev/logs/vmksft/mptcp-dbg/results/412720/1-mptcp-join-sh/stderr Fixes: f8a1d9b ("mptcp: make fallback action and fallback decision atomic") Cc: stable@vger.kernel.org Signed-off-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org> Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org> Link: https://patch.msgid.link/20251205-net-mptcp-misc-fixes-6-19-rc1-v1-4-9e4781a6c1b8@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
krishnachaitanya-linux
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Feb 24, 2026
The IPv4 code path in __ip_vs_get_out_rt() calls dst_link_failure() without ensuring skb->dev is set, leading to a NULL pointer dereference in fib_compute_spec_dst() when ipv4_link_failure() attempts to send ICMP destination unreachable messages. The issue emerged after commit ed0de45 ("ipv4: recompile ip options in ipv4_link_failure") started calling __ip_options_compile() from ipv4_link_failure(). This code path eventually calls fib_compute_spec_dst() which dereferences skb->dev. An attempt was made to fix the NULL skb->dev dereference in commit 0113d9c ("ipv4: fix null-deref in ipv4_link_failure"), but it only addressed the immediate dev_net(skb->dev) dereference by using a fallback device. The fix was incomplete because fib_compute_spec_dst() later in the call chain still accesses skb->dev directly, which remains NULL when IPVS calls dst_link_failure(). The crash occurs when: 1. IPVS processes a packet in NAT mode with a misconfigured destination 2. Route lookup fails in __ip_vs_get_out_rt() before establishing a route 3. The error path calls dst_link_failure(skb) with skb->dev == NULL 4. ipv4_link_failure() → ipv4_send_dest_unreach() → __ip_options_compile() → fib_compute_spec_dst() 5. fib_compute_spec_dst() dereferences NULL skb->dev Apply the same fix used for IPv6 in commit 326bf17 ("ipvs: fix ipv6 route unreach panic"): set skb->dev from skb_dst(skb)->dev before calling dst_link_failure(). KASAN: null-ptr-deref in range [0x0000000000000328-0x000000000000032f] CPU: 1 PID: 12732 Comm: syz.1.3469 Not tainted 6.6.114 #2 RIP: 0010:__in_dev_get_rcu include/linux/inetdevice.h:233 RIP: 0010:fib_compute_spec_dst+0x17a/0x9f0 net/ipv4/fib_frontend.c:285 Call Trace: <TASK> spec_dst_fill net/ipv4/ip_options.c:232 spec_dst_fill net/ipv4/ip_options.c:229 __ip_options_compile+0x13a1/0x17d0 net/ipv4/ip_options.c:330 ipv4_send_dest_unreach net/ipv4/route.c:1252 ipv4_link_failure+0x702/0xb80 net/ipv4/route.c:1265 dst_link_failure include/net/dst.h:437 __ip_vs_get_out_rt+0x15fd/0x19e0 net/netfilter/ipvs/ip_vs_xmit.c:412 ip_vs_nat_xmit+0x1d8/0xc80 net/netfilter/ipvs/ip_vs_xmit.c:764 Fixes: ed0de45 ("ipv4: recompile ip options in ipv4_link_failure") Signed-off-by: Slavin Liu <slavin452@gmail.com> Acked-by: Julian Anastasov <ja@ssi.bg> Signed-off-by: Florian Westphal <fw@strlen.de>
krishnachaitanya-linux
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Feb 24, 2026
Fix a loop scenario of ethx:egress->ethx:egress
Example setup to reproduce:
tc qdisc add dev ethx root handle 1: drr
tc filter add dev ethx parent 1: protocol ip prio 1 matchall \
action mirred egress redirect dev ethx
Now ping out of ethx and you get a deadlock:
[ 116.892898][ T307] ============================================
[ 116.893182][ T307] WARNING: possible recursive locking detected
[ 116.893418][ T307] 6.18.0-rc6-01205-ge05021a829b8-dirty #204 Not tainted
[ 116.893682][ T307] --------------------------------------------
[ 116.893926][ T307] ping/307 is trying to acquire lock:
[ 116.894133][ T307] ffff88800c122908 (&sch->root_lock_key){+...}-{3:3}, at: __dev_queue_xmit+0x2210/0x3b50
[ 116.894517][ T307]
[ 116.894517][ T307] but task is already holding lock:
[ 116.894836][ T307] ffff88800c122908 (&sch->root_lock_key){+...}-{3:3}, at: __dev_queue_xmit+0x2210/0x3b50
[ 116.895252][ T307]
[ 116.895252][ T307] other info that might help us debug this:
[ 116.895608][ T307] Possible unsafe locking scenario:
[ 116.895608][ T307]
[ 116.895901][ T307] CPU0
[ 116.896057][ T307] ----
[ 116.896200][ T307] lock(&sch->root_lock_key);
[ 116.896392][ T307] lock(&sch->root_lock_key);
[ 116.896605][ T307]
[ 116.896605][ T307] *** DEADLOCK ***
[ 116.896605][ T307]
[ 116.896864][ T307] May be due to missing lock nesting notation
[ 116.896864][ T307]
[ 116.897123][ T307] 6 locks held by ping/307:
[ 116.897302][ T307] #0: ffff88800b4b0250 (sk_lock-AF_INET){+.+.}-{0:0}, at: raw_sendmsg+0xb20/0x2cf0
[ 116.897808][ T307] #1: ffffffff88c839c0 (rcu_read_lock){....}-{1:3}, at: ip_output+0xa9/0x600
[ 116.898138][ T307] #2: ffffffff88c839c0 (rcu_read_lock){....}-{1:3}, at: ip_finish_output2+0x2c6/0x1ee0
[ 116.898459][ T307] #3: ffffffff88c83960 (rcu_read_lock_bh){....}-{1:3}, at: __dev_queue_xmit+0x200/0x3b50
[ 116.898782][ T307] #4: ffff88800c122908 (&sch->root_lock_key){+...}-{3:3}, at: __dev_queue_xmit+0x2210/0x3b50
[ 116.899132][ T307] #5: ffffffff88c83960 (rcu_read_lock_bh){....}-{1:3}, at: __dev_queue_xmit+0x200/0x3b50
[ 116.899442][ T307]
[ 116.899442][ T307] stack backtrace:
[ 116.899667][ T307] CPU: 2 UID: 0 PID: 307 Comm: ping Not tainted 6.18.0-rc6-01205-ge05021a829b8-dirty #204 PREEMPT(voluntary)
[ 116.899672][ T307] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[ 116.899675][ T307] Call Trace:
[ 116.899678][ T307] <TASK>
[ 116.899680][ T307] dump_stack_lvl+0x6f/0xb0
[ 116.899688][ T307] print_deadlock_bug.cold+0xc0/0xdc
[ 116.899695][ T307] __lock_acquire+0x11f7/0x1be0
[ 116.899704][ T307] lock_acquire+0x162/0x300
[ 116.899707][ T307] ? __dev_queue_xmit+0x2210/0x3b50
[ 116.899713][ T307] ? srso_alias_return_thunk+0x5/0xfbef5
[ 116.899717][ T307] ? stack_trace_save+0x93/0xd0
[ 116.899723][ T307] _raw_spin_lock+0x30/0x40
[ 116.899728][ T307] ? __dev_queue_xmit+0x2210/0x3b50
[ 116.899731][ T307] __dev_queue_xmit+0x2210/0x3b50
Fixes: 178ca30 ("Revert "net/sched: Fix mirred deadlock on device recursion"")
Tested-by: Victor Nogueira <victor@mojatatu.com>
Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com>
Link: https://patch.msgid.link/20251210162255.1057663-1-jhs@mojatatu.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
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Feb 24, 2026
A race condition was found in sg_proc_debug_helper(). It was observed on a system using an IBM LTO-9 SAS Tape Drive (ULTRIUM-TD9) and monitoring /proc/scsi/sg/debug every second. A very large elapsed time would sometimes appear. This is caused by two race conditions. We reproduced the issue with an IBM ULTRIUM-HH9 tape drive on an x86_64 architecture. A patched kernel was built, and the race condition could not be observed anymore after the application of this patch. A reproducer C program utilising the scsi_debug module was also built by Changhui Zhong and can be viewed here: https://github.com/MichaelRabek/linux-tests/blob/master/drivers/scsi/sg/sg_race_trigger.c The first race happens between the reading of hp->duration in sg_proc_debug_helper() and request completion in sg_rq_end_io(). The hp->duration member variable may hold either of two types of information: #1 - The start time of the request. This value is present while the request is not yet finished. #2 - The total execution time of the request (end_time - start_time). If sg_proc_debug_helper() executes *after* the value of hp->duration was changed from #1 to #2, but *before* srp->done is set to 1 in sg_rq_end_io(), a fresh timestamp is taken in the else branch, and the elapsed time (value type #2) is subtracted from a timestamp, which cannot yield a valid elapsed time (which is a type #2 value as well). To fix this issue, the value of hp->duration must change under the protection of the sfp->rq_list_lock in sg_rq_end_io(). Since sg_proc_debug_helper() takes this read lock, the change to srp->done and srp->header.duration will happen atomically from the perspective of sg_proc_debug_helper() and the race condition is thus eliminated. The second race condition happens between sg_proc_debug_helper() and sg_new_write(). Even though hp->duration is set to the current time stamp in sg_add_request() under the write lock's protection, it gets overwritten by a call to get_sg_io_hdr(), which calls copy_from_user() to copy struct sg_io_hdr from userspace into kernel space. hp->duration is set to the start time again in sg_common_write(). If sg_proc_debug_helper() is called between these two calls, an arbitrary value set by userspace (usually zero) is used to compute the elapsed time. To fix this issue, hp->duration must be set to the current timestamp again after get_sg_io_hdr() returns successfully. A small race window still exists between get_sg_io_hdr() and setting hp->duration, but this window is only a few instructions wide and does not result in observable issues in practice, as confirmed by testing. Additionally, we fix the format specifier from %d to %u for printing unsigned int values in sg_proc_debug_helper(). Signed-off-by: Michal Rábek <mrabek@redhat.com> Suggested-by: Tomas Henzl <thenzl@redhat.com> Tested-by: Changhui Zhong <czhong@redhat.com> Reviewed-by: Ewan D. Milne <emilne@redhat.com> Reviewed-by: John Meneghini <jmeneghi@redhat.com> Reviewed-by: Tomas Henzl <thenzl@redhat.com> Link: https://patch.msgid.link/20251212160900.64924-1-mrabek@redhat.com Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
krishnachaitanya-linux
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Feb 24, 2026
When a page is freed it coalesces with a buddy into a higher order page while possible. When the buddy page migrate type differs, it is expected to be updated to match the one of the page being freed. However, only the first pageblock of the buddy page is updated, while the rest of the pageblocks are left unchanged. That causes warnings in later expand() and other code paths (like below), since an inconsistency between migration type of the list containing the page and the page-owned pageblocks migration types is introduced. [ 308.986589] ------------[ cut here ]------------ [ 308.987227] page type is 0, passed migratetype is 1 (nr=256) [ 308.987275] WARNING: CPU: 1 PID: 5224 at mm/page_alloc.c:812 expand+0x23c/0x270 [ 308.987293] Modules linked in: algif_hash(E) af_alg(E) nft_fib_inet(E) nft_fib_ipv4(E) nft_fib_ipv6(E) nft_fib(E) nft_reject_inet(E) nf_reject_ipv4(E) nf_reject_ipv6(E) nft_reject(E) nft_ct(E) nft_chain_nat(E) nf_nat(E) nf_conntrack(E) nf_defrag_ipv6(E) nf_defrag_ipv4(E) nf_tables(E) s390_trng(E) vfio_ccw(E) mdev(E) vfio_iommu_type1(E) vfio(E) sch_fq_codel(E) drm(E) i2c_core(E) drm_panel_orientation_quirks(E) loop(E) nfnetlink(E) vsock_loopback(E) vmw_vsock_virtio_transport_common(E) vsock(E) ctcm(E) fsm(E) diag288_wdt(E) watchdog(E) zfcp(E) scsi_transport_fc(E) ghash_s390(E) prng(E) aes_s390(E) des_generic(E) des_s390(E) libdes(E) sha3_512_s390(E) sha3_256_s390(E) sha_common(E) paes_s390(E) crypto_engine(E) pkey_cca(E) pkey_ep11(E) zcrypt(E) rng_core(E) pkey_pckmo(E) pkey(E) autofs4(E) [ 308.987439] Unloaded tainted modules: hmac_s390(E):2 [ 308.987650] CPU: 1 UID: 0 PID: 5224 Comm: mempig_verify Kdump: loaded Tainted: G E 6.18.0-gcc-bpf-debug #431 PREEMPT [ 308.987657] Tainted: [E]=UNSIGNED_MODULE [ 308.987661] Hardware name: IBM 3906 M04 704 (z/VM 7.3.0) [ 308.987666] Krnl PSW : 0404f00180000000 00000349976fa600 (expand+0x240/0x270) [ 308.987676] R:0 T:1 IO:0 EX:0 Key:0 M:1 W:0 P:0 AS:3 CC:3 PM:0 RI:0 EA:3 [ 308.987682] Krnl GPRS: 0000034980000004 0000000000000005 0000000000000030 000003499a0e6d88 [ 308.987688] 0000000000000005 0000034980000005 000002be803ac000 0000023efe6c8300 [ 308.987692] 0000000000000008 0000034998d57290 000002be00000100 0000023e00000008 [ 308.987696] 0000000000000000 0000000000000000 00000349976fa5fc 000002c99b1eb6f0 [ 308.987708] Krnl Code: 00000349976fa5f0: c020008a02f2 larl %r2,000003499883abd4 00000349976fa5f6: c0e5ffe3f4b5 brasl %r14,0000034997378f60 #00000349976fa5fc: af000000 mc 0,0 >00000349976fa600: a7f4ff4c brc 15,00000349976fa498 00000349976fa604: b9040026 lgr %r2,%r6 00000349976fa608: c0300088317f larl %r3,0000034998800906 00000349976fa60e: c0e5fffdb6e1 brasl %r14,00000349976b13d0 00000349976fa614: af000000 mc 0,0 [ 308.987734] Call Trace: [ 308.987738] [<00000349976fa600>] expand+0x240/0x270 [ 308.987744] ([<00000349976fa5fc>] expand+0x23c/0x270) [ 308.987749] [<00000349976ff95e>] rmqueue_bulk+0x71e/0x940 [ 308.987754] [<00000349976ffd7e>] __rmqueue_pcplist+0x1fe/0x2a0 [ 308.987759] [<0000034997700966>] rmqueue.isra.0+0xb46/0xf40 [ 308.987763] [<0000034997703ec8>] get_page_from_freelist+0x198/0x8d0 [ 308.987768] [<0000034997706fa8>] __alloc_frozen_pages_noprof+0x198/0x400 [ 308.987774] [<00000349977536f8>] alloc_pages_mpol+0xb8/0x220 [ 308.987781] [<0000034997753bf6>] folio_alloc_mpol_noprof+0x26/0xc0 [ 308.987786] [<0000034997753e4c>] vma_alloc_folio_noprof+0x6c/0xa0 [ 308.987791] [<0000034997775b22>] vma_alloc_anon_folio_pmd+0x42/0x240 [ 308.987799] [<000003499777bfea>] __do_huge_pmd_anonymous_page+0x3a/0x210 [ 308.987804] [<00000349976cb08e>] __handle_mm_fault+0x4de/0x500 [ 308.987809] [<00000349976cb14c>] handle_mm_fault+0x9c/0x3a0 [ 308.987813] [<000003499734d70e>] do_exception+0x1de/0x540 [ 308.987822] [<0000034998387390>] __do_pgm_check+0x130/0x220 [ 308.987830] [<000003499839a934>] pgm_check_handler+0x114/0x160 [ 308.987838] 3 locks held by mempig_verify/5224: [ 308.987842] #0: 0000023ea44c1e08 (vm_lock){++++}-{0:0}, at: lock_vma_under_rcu+0xb2/0x2a0 [ 308.987859] #1: 0000023ee4d41b18 (&pcp->lock){+.+.}-{2:2}, at: rmqueue.isra.0+0xad6/0xf40 [ 308.987871] #2: 0000023efe6c8998 (&zone->lock){..-.}-{2:2}, at: rmqueue_bulk+0x5a/0x940 [ 308.987886] Last Breaking-Event-Address: [ 308.987890] [<0000034997379096>] __warn_printk+0x136/0x140 [ 308.987897] irq event stamp: 52330356 [ 308.987901] hardirqs last enabled at (52330355): [<000003499838742e>] __do_pgm_check+0x1ce/0x220 [ 308.987907] hardirqs last disabled at (52330356): [<000003499839932e>] _raw_spin_lock_irqsave+0x9e/0xe0 [ 308.987913] softirqs last enabled at (52329882): [<0000034997383786>] handle_softirqs+0x2c6/0x530 [ 308.987922] softirqs last disabled at (52329859): [<0000034997382f86>] __irq_exit_rcu+0x126/0x140 [ 308.987929] ---[ end trace 0000000000000000 ]--- [ 308.987936] ------------[ cut here ]------------ [ 308.987940] page type is 0, passed migratetype is 1 (nr=256) [ 308.987951] WARNING: CPU: 1 PID: 5224 at mm/page_alloc.c:860 __del_page_from_free_list+0x1be/0x1e0 [ 308.987960] Modules linked in: algif_hash(E) af_alg(E) nft_fib_inet(E) nft_fib_ipv4(E) nft_fib_ipv6(E) nft_fib(E) nft_reject_inet(E) nf_reject_ipv4(E) nf_reject_ipv6(E) nft_reject(E) nft_ct(E) nft_chain_nat(E) nf_nat(E) nf_conntrack(E) nf_defrag_ipv6(E) nf_defrag_ipv4(E) nf_tables(E) s390_trng(E) vfio_ccw(E) mdev(E) vfio_iommu_type1(E) vfio(E) sch_fq_codel(E) drm(E) i2c_core(E) drm_panel_orientation_quirks(E) loop(E) nfnetlink(E) vsock_loopback(E) vmw_vsock_virtio_transport_common(E) vsock(E) ctcm(E) fsm(E) diag288_wdt(E) watchdog(E) zfcp(E) scsi_transport_fc(E) ghash_s390(E) prng(E) aes_s390(E) des_generic(E) des_s390(E) libdes(E) sha3_512_s390(E) sha3_256_s390(E) sha_common(E) paes_s390(E) crypto_engine(E) pkey_cca(E) pkey_ep11(E) zcrypt(E) rng_core(E) pkey_pckmo(E) pkey(E) autofs4(E) [ 308.988070] Unloaded tainted modules: hmac_s390(E):2 [ 308.988087] CPU: 1 UID: 0 PID: 5224 Comm: mempig_verify Kdump: loaded Tainted: G W E 6.18.0-gcc-bpf-debug #431 PREEMPT [ 308.988095] Tainted: [W]=WARN, [E]=UNSIGNED_MODULE [ 308.988100] Hardware name: IBM 3906 M04 704 (z/VM 7.3.0) [ 308.988105] Krnl PSW : 0404f00180000000 00000349976f9e32 (__del_page_from_free_list+0x1c2/0x1e0) [ 308.988118] R:0 T:1 IO:0 EX:0 Key:0 M:1 W:0 P:0 AS:3 CC:3 PM:0 RI:0 EA:3 [ 308.988127] Krnl GPRS: 0000034980000004 0000000000000005 0000000000000030 000003499a0e6d88 [ 308.988133] 0000000000000005 0000034980000005 0000034998d57290 0000023efe6c8300 [ 308.988139] 0000000000000001 0000000000000008 000002be00000100 000002be803ac000 [ 308.988144] 0000000000000000 0000000000000001 00000349976f9e2e 000002c99b1eb728 [ 308.988153] Krnl Code: 00000349976f9e22: c020008a06d9 larl %r2,000003499883abd4 00000349976f9e28: c0e5ffe3f89c brasl %r14,0000034997378f60 #00000349976f9e2e: af000000 mc 0,0 >00000349976f9e32: a7f4ff4e brc 15,00000349976f9cce 00000349976f9e36: b904002b lgr %r2,%r11 00000349976f9e3a: c030008a06e7 larl %r3,000003499883ac08 00000349976f9e40: c0e5fffdbac8 brasl %r14,00000349976b13d0 00000349976f9e46: af000000 mc 0,0 [ 308.988184] Call Trace: [ 308.988188] [<00000349976f9e32>] __del_page_from_free_list+0x1c2/0x1e0 [ 308.988195] ([<00000349976f9e2e>] __del_page_from_free_list+0x1be/0x1e0) [ 308.988202] [<00000349976ff946>] rmqueue_bulk+0x706/0x940 [ 308.988208] [<00000349976ffd7e>] __rmqueue_pcplist+0x1fe/0x2a0 [ 308.988214] [<0000034997700966>] rmqueue.isra.0+0xb46/0xf40 [ 308.988221] [<0000034997703ec8>] get_page_from_freelist+0x198/0x8d0 [ 308.988227] [<0000034997706fa8>] __alloc_frozen_pages_noprof+0x198/0x400 [ 308.988233] [<00000349977536f8>] alloc_pages_mpol+0xb8/0x220 [ 308.988240] [<0000034997753bf6>] folio_alloc_mpol_noprof+0x26/0xc0 [ 308.988247] [<0000034997753e4c>] vma_alloc_folio_noprof+0x6c/0xa0 [ 308.988253] [<0000034997775b22>] vma_alloc_anon_folio_pmd+0x42/0x240 [ 308.988260] [<000003499777bfea>] __do_huge_pmd_anonymous_page+0x3a/0x210 [ 308.988267] [<00000349976cb08e>] __handle_mm_fault+0x4de/0x500 [ 308.988273] [<00000349976cb14c>] handle_mm_fault+0x9c/0x3a0 [ 308.988279] [<000003499734d70e>] do_exception+0x1de/0x540 [ 308.988286] [<0000034998387390>] __do_pgm_check+0x130/0x220 [ 308.988293] [<000003499839a934>] pgm_check_handler+0x114/0x160 [ 308.988300] 3 locks held by mempig_verify/5224: [ 308.988305] #0: 0000023ea44c1e08 (vm_lock){++++}-{0:0}, at: lock_vma_under_rcu+0xb2/0x2a0 [ 308.988322] #1: 0000023ee4d41b18 (&pcp->lock){+.+.}-{2:2}, at: rmqueue.isra.0+0xad6/0xf40 [ 308.988334] #2: 0000023efe6c8998 (&zone->lock){..-.}-{2:2}, at: rmqueue_bulk+0x5a/0x940 [ 308.988346] Last Breaking-Event-Address: [ 308.988350] [<0000034997379096>] __warn_printk+0x136/0x140 [ 308.988356] irq event stamp: 52330356 [ 308.988360] hardirqs last enabled at (52330355): [<000003499838742e>] __do_pgm_check+0x1ce/0x220 [ 308.988366] hardirqs last disabled at (52330356): [<000003499839932e>] _raw_spin_lock_irqsave+0x9e/0xe0 [ 308.988373] softirqs last enabled at (52329882): [<0000034997383786>] handle_softirqs+0x2c6/0x530 [ 308.988380] softirqs last disabled at (52329859): [<0000034997382f86>] __irq_exit_rcu+0x126/0x140 [ 308.988388] ---[ end trace 0000000000000000 ]--- Link: https://lkml.kernel.org/r/20251215081002.3353900A9c-agordeev@linux.ibm.com Link: https://lkml.kernel.org/r/20251212151457.3898073Add-agordeev@linux.ibm.com Fixes: e6cf9e1 ("mm: page_alloc: fix up block types when merging compatible blocks") Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com> Reported-by: Marc Hartmayer <mhartmay@linux.ibm.com> Closes: https://lore.kernel.org/linux-mm/87wmalyktd.fsf@linux.ibm.com/ Acked-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: Wei Yang <richard.weiyang@gmail.com> Cc: Marc Hartmayer <mhartmay@linux.ibm.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
krishnachaitanya-linux
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Feb 24, 2026
When running the Rust maple tree kunit tests with lockdep, you may trigger a warning that looks like this: lib/maple_tree.c:780 suspicious rcu_dereference_check() usage! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 no locks held by kunit_try_catch/344. stack backtrace: CPU: 3 UID: 0 PID: 344 Comm: kunit_try_catch Tainted: G N 6.19.0-rc1+ #2 NONE Tainted: [N]=TEST Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.17.0-0-gb52ca86e094d-prebuilt.qemu.org 04/01/2014 Call Trace: <TASK> dump_stack_lvl+0x71/0x90 lockdep_rcu_suspicious+0x150/0x190 mas_start+0x104/0x150 mas_find+0x179/0x240 _RINvNtCs5QSdWC790r4_4core3ptr13drop_in_placeINtNtCs1cdwasc6FUb_6kernel10maple_tree9MapleTreeINtNtNtBL_5alloc4kbox3BoxlNtNtB1x_9allocator7KmallocEEECsgxAQYCfdR72_25doctests_kernel_generated+0xaf/0x130 rust_doctest_kernel_maple_tree_rs_0+0x600/0x6b0 ? lock_release+0xeb/0x2a0 ? kunit_try_catch_run+0x210/0x210 kunit_try_run_case+0x74/0x160 ? kunit_try_catch_run+0x210/0x210 kunit_generic_run_threadfn_adapter+0x12/0x30 kthread+0x21c/0x230 ? __do_trace_sched_kthread_stop_ret+0x40/0x40 ret_from_fork+0x16c/0x270 ? __do_trace_sched_kthread_stop_ret+0x40/0x40 ret_from_fork_asm+0x11/0x20 </TASK> This is because the destructor of maple tree calls mas_find() without taking rcu_read_lock() or the spinlock. Doing that is actually ok in this case since the destructor has exclusive access to the entire maple tree, but it triggers a lockdep warning. To fix that, take the rcu read lock. In the future, it's possible that memory reclaim could gain a feature where it reallocates entries in maple trees even if no user-code is touching it. If that feature is added, then this use of rcu read lock would become load-bearing, so I did not make it conditional on lockdep. We have to repeatedly take and release rcu because the destructor of T might perform operations that sleep. Link: https://lkml.kernel.org/r/20251217-maple-drop-rcu-v1-1-702af063573f@google.com Fixes: da939ef ("rust: maple_tree: add MapleTree") Signed-off-by: Alice Ryhl <aliceryhl@google.com> Reported-by: Andreas Hindborg <a.hindborg@kernel.org> Closes: https://rust-for-linux.zulipchat.com/#narrow/channel/x/topic/x/near/564215108 Reviewed-by: Gary Guo <gary@garyguo.net> Reviewed-by: Daniel Almeida <daniel.almeida@collabora.com> Cc: Andrew Ballance <andrewjballance@gmail.com> Cc: Björn Roy Baron <bjorn3_gh@protonmail.com> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Danilo Krummrich <dakr@kernel.org> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Miguel Ojeda <ojeda@kernel.org> Cc: Trevor Gross <tmgross@umich.edu> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
krishnachaitanya-linux
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Feb 24, 2026
… to macb_open() In the non-RT kernel, local_bh_disable() merely disables preemption, whereas it maps to an actual spin lock in the RT kernel. Consequently, when attempting to refill RX buffers via netdev_alloc_skb() in macb_mac_link_up(), a deadlock scenario arises as follows: WARNING: possible circular locking dependency detected 6.18.0-08691-g2061f18ad76e #39 Not tainted ------------------------------------------------------ kworker/0:0/8 is trying to acquire lock: ffff00080369bbe0 (&bp->lock){+.+.}-{3:3}, at: macb_start_xmit+0x808/0xb7c but task is already holding lock: ffff000803698e58 (&queue->tx_ptr_lock){+...}-{3:3}, at: macb_start_xmit +0x148/0xb7c which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (&queue->tx_ptr_lock){+...}-{3:3}: rt_spin_lock+0x50/0x1f0 macb_start_xmit+0x148/0xb7c dev_hard_start_xmit+0x94/0x284 sch_direct_xmit+0x8c/0x37c __dev_queue_xmit+0x708/0x1120 neigh_resolve_output+0x148/0x28c ip6_finish_output2+0x2c0/0xb2c __ip6_finish_output+0x114/0x308 ip6_output+0xc4/0x4a4 mld_sendpack+0x220/0x68c mld_ifc_work+0x2a8/0x4f4 process_one_work+0x20c/0x5f8 worker_thread+0x1b0/0x35c kthread+0x144/0x200 ret_from_fork+0x10/0x20 -> #2 (_xmit_ETHER#2){+...}-{3:3}: rt_spin_lock+0x50/0x1f0 sch_direct_xmit+0x11c/0x37c __dev_queue_xmit+0x708/0x1120 neigh_resolve_output+0x148/0x28c ip6_finish_output2+0x2c0/0xb2c __ip6_finish_output+0x114/0x308 ip6_output+0xc4/0x4a4 mld_sendpack+0x220/0x68c mld_ifc_work+0x2a8/0x4f4 process_one_work+0x20c/0x5f8 worker_thread+0x1b0/0x35c kthread+0x144/0x200 ret_from_fork+0x10/0x20 -> #1 ((softirq_ctrl.lock)){+.+.}-{3:3}: lock_release+0x250/0x348 __local_bh_enable_ip+0x7c/0x240 __netdev_alloc_skb+0x1b4/0x1d8 gem_rx_refill+0xdc/0x240 gem_init_rings+0xb4/0x108 macb_mac_link_up+0x9c/0x2b4 phylink_resolve+0x170/0x614 process_one_work+0x20c/0x5f8 worker_thread+0x1b0/0x35c kthread+0x144/0x200 ret_from_fork+0x10/0x20 -> #0 (&bp->lock){+.+.}-{3:3}: __lock_acquire+0x15a8/0x2084 lock_acquire+0x1cc/0x350 rt_spin_lock+0x50/0x1f0 macb_start_xmit+0x808/0xb7c dev_hard_start_xmit+0x94/0x284 sch_direct_xmit+0x8c/0x37c __dev_queue_xmit+0x708/0x1120 neigh_resolve_output+0x148/0x28c ip6_finish_output2+0x2c0/0xb2c __ip6_finish_output+0x114/0x308 ip6_output+0xc4/0x4a4 mld_sendpack+0x220/0x68c mld_ifc_work+0x2a8/0x4f4 process_one_work+0x20c/0x5f8 worker_thread+0x1b0/0x35c kthread+0x144/0x200 ret_from_fork+0x10/0x20 other info that might help us debug this: Chain exists of: &bp->lock --> _xmit_ETHER#2 --> &queue->tx_ptr_lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&queue->tx_ptr_lock); lock(_xmit_ETHER#2); lock(&queue->tx_ptr_lock); lock(&bp->lock); *** DEADLOCK *** Call trace: show_stack+0x18/0x24 (C) dump_stack_lvl+0xa0/0xf0 dump_stack+0x18/0x24 print_circular_bug+0x28c/0x370 check_noncircular+0x198/0x1ac __lock_acquire+0x15a8/0x2084 lock_acquire+0x1cc/0x350 rt_spin_lock+0x50/0x1f0 macb_start_xmit+0x808/0xb7c dev_hard_start_xmit+0x94/0x284 sch_direct_xmit+0x8c/0x37c __dev_queue_xmit+0x708/0x1120 neigh_resolve_output+0x148/0x28c ip6_finish_output2+0x2c0/0xb2c __ip6_finish_output+0x114/0x308 ip6_output+0xc4/0x4a4 mld_sendpack+0x220/0x68c mld_ifc_work+0x2a8/0x4f4 process_one_work+0x20c/0x5f8 worker_thread+0x1b0/0x35c kthread+0x144/0x200 ret_from_fork+0x10/0x20 Notably, invoking the mog_init_rings() callback upon link establishment is unnecessary. Instead, we can exclusively call mog_init_rings() within the ndo_open() callback. This adjustment resolves the deadlock issue. Furthermore, since MACB_CAPS_MACB_IS_EMAC cases do not use mog_init_rings() when opening the network interface via at91ether_open(), moving mog_init_rings() to macb_open() also eliminates the MACB_CAPS_MACB_IS_EMAC check. Fixes: 633e98a ("net: macb: use resolved link config in mac_link_up()") Cc: stable@vger.kernel.org Suggested-by: Kevin Hao <kexin.hao@windriver.com> Signed-off-by: Xiaolei Wang <xiaolei.wang@windriver.com> Link: https://patch.msgid.link/20251222015624.1994551-1-xiaolei.wang@windriver.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
krishnachaitanya-linux
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Feb 24, 2026
ctx->tcxt_list holds the tasks using this ring, and it's currently
protected by the normal ctx->uring_lock. However, this can cause a
circular locking issue, as reported by syzbot, where cancelations off
exec end up needing to remove an entry from this list:
======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Tainted: G L
------------------------------------------------------
syz.0.9999/12287 is trying to acquire lock:
ffff88805851c0a8 (&ctx->uring_lock){+.+.}-{4:4}, at: io_uring_del_tctx_node+0xf0/0x2c0 io_uring/tctx.c:179
but task is already holding lock:
ffff88802db5a2e0 (&sig->cred_guard_mutex){+.+.}-{4:4}, at: prepare_bprm_creds fs/exec.c:1360 [inline]
ffff88802db5a2e0 (&sig->cred_guard_mutex){+.+.}-{4:4}, at: bprm_execve+0xb9/0x1400 fs/exec.c:1733
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #2 (&sig->cred_guard_mutex){+.+.}-{4:4}:
__mutex_lock_common kernel/locking/mutex.c:614 [inline]
__mutex_lock+0x187/0x1350 kernel/locking/mutex.c:776
proc_pid_attr_write+0x547/0x630 fs/proc/base.c:2837
vfs_write+0x27e/0xb30 fs/read_write.c:684
ksys_write+0x145/0x250 fs/read_write.c:738
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
-> #1 (sb_writers#3){.+.+}-{0:0}:
percpu_down_read_internal include/linux/percpu-rwsem.h:53 [inline]
percpu_down_read_freezable include/linux/percpu-rwsem.h:83 [inline]
__sb_start_write include/linux/fs/super.h:19 [inline]
sb_start_write+0x4d/0x1c0 include/linux/fs/super.h:125
mnt_want_write+0x41/0x90 fs/namespace.c:499
open_last_lookups fs/namei.c:4529 [inline]
path_openat+0xadd/0x3dd0 fs/namei.c:4784
do_filp_open+0x1fa/0x410 fs/namei.c:4814
io_openat2+0x3e0/0x5c0 io_uring/openclose.c:143
__io_issue_sqe+0x181/0x4b0 io_uring/io_uring.c:1792
io_issue_sqe+0x165/0x1060 io_uring/io_uring.c:1815
io_queue_sqe io_uring/io_uring.c:2042 [inline]
io_submit_sqe io_uring/io_uring.c:2320 [inline]
io_submit_sqes+0xbf4/0x2140 io_uring/io_uring.c:2434
__do_sys_io_uring_enter io_uring/io_uring.c:3280 [inline]
__se_sys_io_uring_enter+0x2e0/0x2b60 io_uring/io_uring.c:3219
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
-> #0 (&ctx->uring_lock){+.+.}-{4:4}:
check_prev_add kernel/locking/lockdep.c:3165 [inline]
check_prevs_add kernel/locking/lockdep.c:3284 [inline]
validate_chain kernel/locking/lockdep.c:3908 [inline]
__lock_acquire+0x15a6/0x2cf0 kernel/locking/lockdep.c:5237
lock_acquire+0x107/0x340 kernel/locking/lockdep.c:5868
__mutex_lock_common kernel/locking/mutex.c:614 [inline]
__mutex_lock+0x187/0x1350 kernel/locking/mutex.c:776
io_uring_del_tctx_node+0xf0/0x2c0 io_uring/tctx.c:179
io_uring_clean_tctx+0xd4/0x1a0 io_uring/tctx.c:195
io_uring_cancel_generic+0x6ca/0x7d0 io_uring/cancel.c:646
io_uring_task_cancel include/linux/io_uring.h:24 [inline]
begin_new_exec+0x10ed/0x2440 fs/exec.c:1131
load_elf_binary+0x9f8/0x2d70 fs/binfmt_elf.c:1010
search_binary_handler fs/exec.c:1669 [inline]
exec_binprm fs/exec.c:1701 [inline]
bprm_execve+0x92e/0x1400 fs/exec.c:1753
do_execveat_common+0x510/0x6a0 fs/exec.c:1859
do_execve fs/exec.c:1933 [inline]
__do_sys_execve fs/exec.c:2009 [inline]
__se_sys_execve fs/exec.c:2004 [inline]
__x64_sys_execve+0x94/0xb0 fs/exec.c:2004
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
other info that might help us debug this:
Chain exists of:
&ctx->uring_lock --> sb_writers#3 --> &sig->cred_guard_mutex
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&sig->cred_guard_mutex);
lock(sb_writers#3);
lock(&sig->cred_guard_mutex);
lock(&ctx->uring_lock);
*** DEADLOCK ***
1 lock held by syz.0.9999/12287:
#0: ffff88802db5a2e0 (&sig->cred_guard_mutex){+.+.}-{4:4}, at: prepare_bprm_creds fs/exec.c:1360 [inline]
#0: ffff88802db5a2e0 (&sig->cred_guard_mutex){+.+.}-{4:4}, at: bprm_execve+0xb9/0x1400 fs/exec.c:1733
stack backtrace:
CPU: 0 UID: 0 PID: 12287 Comm: syz.0.9999 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
<TASK>
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
print_circular_bug+0x2e2/0x300 kernel/locking/lockdep.c:2043
check_noncircular+0x12e/0x150 kernel/locking/lockdep.c:2175
check_prev_add kernel/locking/lockdep.c:3165 [inline]
check_prevs_add kernel/locking/lockdep.c:3284 [inline]
validate_chain kernel/locking/lockdep.c:3908 [inline]
__lock_acquire+0x15a6/0x2cf0 kernel/locking/lockdep.c:5237
lock_acquire+0x107/0x340 kernel/locking/lockdep.c:5868
__mutex_lock_common kernel/locking/mutex.c:614 [inline]
__mutex_lock+0x187/0x1350 kernel/locking/mutex.c:776
io_uring_del_tctx_node+0xf0/0x2c0 io_uring/tctx.c:179
io_uring_clean_tctx+0xd4/0x1a0 io_uring/tctx.c:195
io_uring_cancel_generic+0x6ca/0x7d0 io_uring/cancel.c:646
io_uring_task_cancel include/linux/io_uring.h:24 [inline]
begin_new_exec+0x10ed/0x2440 fs/exec.c:1131
load_elf_binary+0x9f8/0x2d70 fs/binfmt_elf.c:1010
search_binary_handler fs/exec.c:1669 [inline]
exec_binprm fs/exec.c:1701 [inline]
bprm_execve+0x92e/0x1400 fs/exec.c:1753
do_execveat_common+0x510/0x6a0 fs/exec.c:1859
do_execve fs/exec.c:1933 [inline]
__do_sys_execve fs/exec.c:2009 [inline]
__se_sys_execve fs/exec.c:2004 [inline]
__x64_sys_execve+0x94/0xb0 fs/exec.c:2004
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ff3a8b8f749
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ff3a9a97038 EFLAGS: 00000246 ORIG_RAX: 000000000000003b
RAX: ffffffffffffffda RBX: 00007ff3a8de5fa0 RCX: 00007ff3a8b8f749
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000200000000400
RBP: 00007ff3a8c13f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ff3a8de6038 R14: 00007ff3a8de5fa0 R15: 00007ff3a8f0fa28
</TASK>
Add a separate lock just for the tctx_list, tctx_lock. This can nest
under ->uring_lock, where necessary, and be used separately for list
manipulation. For the cancelation off exec side, this removes the
need to grab ->uring_lock, hence fixing the circular locking
dependency.
Reported-by: syzbot+b0e3b77ffaa8a4067ce5@syzkaller.appspotmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
krishnachaitanya-linux
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Feb 24, 2026
After rename exchanging (either with the rename exchange operation or regular renames in multiple non-atomic steps) two inodes and at least one of them is a directory, we can end up with a log tree that contains only of the inodes and after a power failure that can result in an attempt to delete the other inode when it should not because it was not deleted before the power failure. In some case that delete attempt fails when the target inode is a directory that contains a subvolume inside it, since the log replay code is not prepared to deal with directory entries that point to root items (only inode items). 1) We have directories "dir1" (inode A) and "dir2" (inode B) under the same parent directory; 2) We have a file (inode C) under directory "dir1" (inode A); 3) We have a subvolume inside directory "dir2" (inode B); 4) All these inodes were persisted in a past transaction and we are currently at transaction N; 5) We rename the file (inode C), so at btrfs_log_new_name() we update inode C's last_unlink_trans to N; 6) We get a rename exchange for "dir1" (inode A) and "dir2" (inode B), so after the exchange "dir1" is inode B and "dir2" is inode A. During the rename exchange we call btrfs_log_new_name() for inodes A and B, but because they are directories, we don't update their last_unlink_trans to N; 7) An fsync against the file (inode C) is done, and because its inode has a last_unlink_trans with a value of N we log its parent directory (inode A) (through btrfs_log_all_parents(), called from btrfs_log_inode_parent()). 8) So we end up with inode B not logged, which now has the old name of inode A. At copy_inode_items_to_log(), when logging inode A, we did not check if we had any conflicting inode to log because inode A has a generation lower than the current transaction (created in a past transaction); 9) After a power failure, when replaying the log tree, since we find that inode A has a new name that conflicts with the name of inode B in the fs tree, we attempt to delete inode B... this is wrong since that directory was never deleted before the power failure, and because there is a subvolume inside that directory, attempting to delete it will fail since replay_dir_deletes() and btrfs_unlink_inode() are not prepared to deal with dir items that point to roots instead of inodes. When that happens the mount fails and we get a stack trace like the following: [87.2314] BTRFS info (device dm-0): start tree-log replay [87.2318] BTRFS critical (device dm-0): failed to delete reference to subvol, root 5 inode 256 parent 259 [87.2332] ------------[ cut here ]------------ [87.2338] BTRFS: Transaction aborted (error -2) [87.2346] WARNING: CPU: 1 PID: 638968 at fs/btrfs/inode.c:4345 __btrfs_unlink_inode+0x416/0x440 [btrfs] [87.2368] Modules linked in: btrfs loop dm_thin_pool (...) [87.2470] CPU: 1 UID: 0 PID: 638968 Comm: mount Tainted: G W 6.18.0-rc7-btrfs-next-218+ #2 PREEMPT(full) [87.2489] Tainted: [W]=WARN [87.2494] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.2-0-gea1b7a073390-prebuilt.qemu.org 04/01/2014 [87.2514] RIP: 0010:__btrfs_unlink_inode+0x416/0x440 [btrfs] [87.2538] Code: c0 89 04 24 (...) [87.2568] RSP: 0018:ffffc0e741f4b9b8 EFLAGS: 00010286 [87.2574] RAX: 0000000000000000 RBX: ffff9d3ec8a6cf60 RCX: 0000000000000000 [87.2582] RDX: 0000000000000002 RSI: ffffffff84ab45a1 RDI: 00000000ffffffff [87.2591] RBP: ffff9d3ec8a6ef20 R08: 0000000000000000 R09: ffffc0e741f4b840 [87.2599] R10: ffff9d45dc1fffa8 R11: 0000000000000003 R12: ffff9d3ee26d77e0 [87.2608] R13: ffffc0e741f4ba98 R14: ffff9d4458040800 R15: ffff9d44b6b7ca10 [87.2618] FS: 00007f7b9603a840(0000) GS:ffff9d4658982000(0000) knlGS:0000000000000000 [87.2629] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [87.2637] CR2: 00007ffc9ec33b98 CR3: 000000011273e003 CR4: 0000000000370ef0 [87.2648] Call Trace: [87.2651] <TASK> [87.2654] btrfs_unlink_inode+0x15/0x40 [btrfs] [87.2661] unlink_inode_for_log_replay+0x27/0xf0 [btrfs] [87.2669] check_item_in_log+0x1ea/0x2c0 [btrfs] [87.2676] replay_dir_deletes+0x16b/0x380 [btrfs] [87.2684] fixup_inode_link_count+0x34b/0x370 [btrfs] [87.2696] fixup_inode_link_counts+0x41/0x160 [btrfs] [87.2703] btrfs_recover_log_trees+0x1ff/0x7c0 [btrfs] [87.2711] ? __pfx_replay_one_buffer+0x10/0x10 [btrfs] [87.2719] open_ctree+0x10bb/0x15f0 [btrfs] [87.2726] btrfs_get_tree.cold+0xb/0x16c [btrfs] [87.2734] ? fscontext_read+0x15c/0x180 [87.2740] ? rw_verify_area+0x50/0x180 [87.2746] vfs_get_tree+0x25/0xd0 [87.2750] vfs_cmd_create+0x59/0xe0 [87.2755] __do_sys_fsconfig+0x4f6/0x6b0 [87.2760] do_syscall_64+0x50/0x1220 [87.2764] entry_SYSCALL_64_after_hwframe+0x76/0x7e [87.2770] RIP: 0033:0x7f7b9625f4aa [87.2775] Code: 73 01 c3 48 (...) [87.2803] RSP: 002b:00007ffc9ec35b08 EFLAGS: 00000246 ORIG_RAX: 00000000000001af [87.2817] RAX: ffffffffffffffda RBX: 0000558bfa91ac20 RCX: 00007f7b9625f4aa [87.2829] RDX: 0000000000000000 RSI: 0000000000000006 RDI: 0000000000000003 [87.2842] RBP: 0000558bfa91b120 R08: 0000000000000000 R09: 0000000000000000 [87.2854] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 [87.2864] R13: 00007f7b963f1580 R14: 00007f7b963f326c R15: 00007f7b963d8a23 [87.2877] </TASK> [87.2882] ---[ end trace 0000000000000000 ]--- [87.2891] BTRFS: error (device dm-0 state A) in __btrfs_unlink_inode:4345: errno=-2 No such entry [87.2904] BTRFS: error (device dm-0 state EAO) in do_abort_log_replay:191: errno=-2 No such entry [87.2915] BTRFS critical (device dm-0 state EAO): log tree (for root 5) leaf currently being processed (slot 7 key (258 12 257)): [87.2929] BTRFS info (device dm-0 state EAO): leaf 30736384 gen 10 total ptrs 7 free space 15712 owner 18446744073709551610 [87.2929] BTRFS info (device dm-0 state EAO): refs 3 lock_owner 0 current 638968 [87.2929] item 0 key (257 INODE_ITEM 0) itemoff 16123 itemsize 160 [87.2929] inode generation 9 transid 10 size 0 nbytes 0 [87.2929] block group 0 mode 40755 links 1 uid 0 gid 0 [87.2929] rdev 0 sequence 7 flags 0x0 [87.2929] atime 1765464494.678070921 [87.2929] ctime 1765464494.686606513 [87.2929] mtime 1765464494.686606513 [87.2929] otime 1765464494.678070921 [87.2929] item 1 key (257 INODE_REF 256) itemoff 16109 itemsize 14 [87.2929] index 4 name_len 4 [87.2929] item 2 key (257 DIR_LOG_INDEX 2) itemoff 16101 itemsize 8 [87.2929] dir log end 2 [87.2929] item 3 key (257 DIR_LOG_INDEX 3) itemoff 16093 itemsize 8 [87.2929] dir log end 18446744073709551615 [87.2930] item 4 key (257 DIR_INDEX 3) itemoff 16060 itemsize 33 [87.2930] location key (258 1 0) type 1 [87.2930] transid 10 data_len 0 name_len 3 [87.2930] item 5 key (258 INODE_ITEM 0) itemoff 15900 itemsize 160 [87.2930] inode generation 9 transid 10 size 0 nbytes 0 [87.2930] block group 0 mode 100644 links 1 uid 0 gid 0 [87.2930] rdev 0 sequence 2 flags 0x0 [87.2930] atime 1765464494.678456467 [87.2930] ctime 1765464494.686606513 [87.2930] mtime 1765464494.678456467 [87.2930] otime 1765464494.678456467 [87.2930] item 6 key (258 INODE_REF 257) itemoff 15887 itemsize 13 [87.2930] index 3 name_len 3 [87.2930] BTRFS critical (device dm-0 state EAO): log replay failed in unlink_inode_for_log_replay:1045 for root 5, stage 3, with error -2: failed to unlink inode 256 parent dir 259 name subvol root 5 [87.2963] BTRFS: error (device dm-0 state EAO) in btrfs_recover_log_trees:7743: errno=-2 No such entry [87.2981] BTRFS: error (device dm-0 state EAO) in btrfs_replay_log:2083: errno=-2 No such entry (Failed to recover log tr So fix this by changing copy_inode_items_to_log() to always detect if there are conflicting inodes for the ref/extref of the inode being logged even if the inode was created in a past transaction. A test case for fstests will follow soon. CC: stable@vger.kernel.org # 6.1+ Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
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…te in qfq_reset `qfq_class->leaf_qdisc->q.qlen > 0` does not imply that the class itself is active. Two qfq_class objects may point to the same leaf_qdisc. This happens when: 1. one QFQ qdisc is attached to the dev as the root qdisc, and 2. another QFQ qdisc is temporarily referenced (e.g., via qdisc_get() / qdisc_put()) and is pending to be destroyed, as in function tc_new_tfilter. When packets are enqueued through the root QFQ qdisc, the shared leaf_qdisc->q.qlen increases. At the same time, the second QFQ qdisc triggers qdisc_put and qdisc_destroy: the qdisc enters qfq_reset() with its own q->q.qlen == 0, but its class's leaf qdisc->q.qlen > 0. Therefore, the qfq_reset would wrongly deactivate an inactive aggregate and trigger a null-deref in qfq_deactivate_agg: [ 0.903172] BUG: kernel NULL pointer dereference, address: 0000000000000000 [ 0.903571] #PF: supervisor write access in kernel mode [ 0.903860] #PF: error_code(0x0002) - not-present page [ 0.904177] PGD 10299b067 P4D 10299b067 PUD 10299c067 PMD 0 [ 0.904502] Oops: Oops: 0002 [#1] SMP NOPTI [ 0.904737] CPU: 0 UID: 0 PID: 135 Comm: exploit Not tainted 6.19.0-rc3+ #2 NONE [ 0.905157] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.17.0-0-gb52ca86e094d-prebuilt.qemu.org 04/01/2014 [ 0.905754] RIP: 0010:qfq_deactivate_agg (include/linux/list.h:992 (discriminator 2) include/linux/list.h:1006 (discriminator 2) net/sched/sch_qfq.c:1367 (discriminator 2) net/sched/sch_qfq.c:1393 (discriminator 2)) [ 0.906046] Code: 0f 84 4d 01 00 00 48 89 70 18 8b 4b 10 48 c7 c2 ff ff ff ff 48 8b 78 08 48 d3 e2 48 21 f2 48 2b 13 48 8b 30 48 d3 ea 8b 4b 18 0 Code starting with the faulting instruction =========================================== 0: 0f 84 4d 01 00 00 je 0x153 6: 48 89 70 18 mov %rsi,0x18(%rax) a: 8b 4b 10 mov 0x10(%rbx),%ecx d: 48 c7 c2 ff ff ff ff mov $0xffffffffffffffff,%rdx 14: 48 8b 78 08 mov 0x8(%rax),%rdi 18: 48 d3 e2 shl %cl,%rdx 1b: 48 21 f2 and %rsi,%rdx 1e: 48 2b 13 sub (%rbx),%rdx 21: 48 8b 30 mov (%rax),%rsi 24: 48 d3 ea shr %cl,%rdx 27: 8b 4b 18 mov 0x18(%rbx),%ecx ... [ 0.907095] RSP: 0018:ffffc900004a39a0 EFLAGS: 00010246 [ 0.907368] RAX: ffff8881043a0880 RBX: ffff888102953340 RCX: 0000000000000000 [ 0.907723] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 [ 0.908100] RBP: ffff888102952180 R08: 0000000000000000 R09: 0000000000000000 [ 0.908451] R10: ffff8881043a0000 R11: 0000000000000000 R12: ffff888102952000 [ 0.908804] R13: ffff888102952180 R14: ffff8881043a0ad8 R15: ffff8881043a0880 [ 0.909179] FS: 000000002a1a0380(0000) GS:ffff888196d8d000(0000) knlGS:0000000000000000 [ 0.909572] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 0.909857] CR2: 0000000000000000 CR3: 0000000102993002 CR4: 0000000000772ef0 [ 0.910247] PKRU: 55555554 [ 0.910391] Call Trace: [ 0.910527] <TASK> [ 0.910638] qfq_reset_qdisc (net/sched/sch_qfq.c:357 net/sched/sch_qfq.c:1485) [ 0.910826] qdisc_reset (include/linux/skbuff.h:2195 include/linux/skbuff.h:2501 include/linux/skbuff.h:3424 include/linux/skbuff.h:3430 net/sched/sch_generic.c:1036) [ 0.911040] __qdisc_destroy (net/sched/sch_generic.c:1076) [ 0.911236] tc_new_tfilter (net/sched/cls_api.c:2447) [ 0.911447] rtnetlink_rcv_msg (net/core/rtnetlink.c:6958) [ 0.911663] ? __pfx_rtnetlink_rcv_msg (net/core/rtnetlink.c:6861) [ 0.911894] netlink_rcv_skb (net/netlink/af_netlink.c:2550) [ 0.912100] netlink_unicast (net/netlink/af_netlink.c:1319 net/netlink/af_netlink.c:1344) [ 0.912296] ? __alloc_skb (net/core/skbuff.c:706) [ 0.912484] netlink_sendmsg (net/netlink/af_netlink.c:1894) [ 0.912682] sock_write_iter (net/socket.c:727 (discriminator 1) net/socket.c:742 (discriminator 1) net/socket.c:1195 (discriminator 1)) [ 0.912880] vfs_write (fs/read_write.c:593 fs/read_write.c:686) [ 0.913077] ksys_write (fs/read_write.c:738) [ 0.913252] do_syscall_64 (arch/x86/entry/syscall_64.c:63 (discriminator 1) arch/x86/entry/syscall_64.c:94 (discriminator 1)) [ 0.913438] entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:131) [ 0.913687] RIP: 0033:0x424c34 [ 0.913844] Code: 89 02 48 c7 c0 ff ff ff ff eb bd 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 80 3d 2d 44 09 00 00 74 13 b8 01 00 00 00 0f 05 9 Code starting with the faulting instruction =========================================== 0: 89 02 mov %eax,(%rdx) 2: 48 c7 c0 ff ff ff ff mov $0xffffffffffffffff,%rax 9: eb bd jmp 0xffffffffffffffc8 b: 66 2e 0f 1f 84 00 00 cs nopw 0x0(%rax,%rax,1) 12: 00 00 00 15: 90 nop 16: f3 0f 1e fa endbr64 1a: 80 3d 2d 44 09 00 00 cmpb $0x0,0x9442d(%rip) # 0x9444e 21: 74 13 je 0x36 23: b8 01 00 00 00 mov $0x1,%eax 28: 0f 05 syscall 2a: 09 .byte 0x9 [ 0.914807] RSP: 002b:00007ffea1938b78 EFLAGS: 00000202 ORIG_RAX: 0000000000000001 [ 0.915197] RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 0000000000424c34 [ 0.915556] RDX: 000000000000003c RSI: 000000002af378c0 RDI: 0000000000000003 [ 0.915912] RBP: 00007ffea1938bc0 R08: 00000000004b8820 R09: 0000000000000000 [ 0.916297] R10: 0000000000000001 R11: 0000000000000202 R12: 00007ffea1938d28 [ 0.916652] R13: 00007ffea1938d38 R14: 00000000004b3828 R15: 0000000000000001 [ 0.917039] </TASK> [ 0.917158] Modules linked in: [ 0.917316] CR2: 0000000000000000 [ 0.917484] ---[ end trace 0000000000000000 ]--- [ 0.917717] RIP: 0010:qfq_deactivate_agg (include/linux/list.h:992 (discriminator 2) include/linux/list.h:1006 (discriminator 2) net/sched/sch_qfq.c:1367 (discriminator 2) net/sched/sch_qfq.c:1393 (discriminator 2)) [ 0.917978] Code: 0f 84 4d 01 00 00 48 89 70 18 8b 4b 10 48 c7 c2 ff ff ff ff 48 8b 78 08 48 d3 e2 48 21 f2 48 2b 13 48 8b 30 48 d3 ea 8b 4b 18 0 Code starting with the faulting instruction =========================================== 0: 0f 84 4d 01 00 00 je 0x153 6: 48 89 70 18 mov %rsi,0x18(%rax) a: 8b 4b 10 mov 0x10(%rbx),%ecx d: 48 c7 c2 ff ff ff ff mov $0xffffffffffffffff,%rdx 14: 48 8b 78 08 mov 0x8(%rax),%rdi 18: 48 d3 e2 shl %cl,%rdx 1b: 48 21 f2 and %rsi,%rdx 1e: 48 2b 13 sub (%rbx),%rdx 21: 48 8b 30 mov (%rax),%rsi 24: 48 d3 ea shr %cl,%rdx 27: 8b 4b 18 mov 0x18(%rbx),%ecx ... [ 0.918902] RSP: 0018:ffffc900004a39a0 EFLAGS: 00010246 [ 0.919198] RAX: ffff8881043a0880 RBX: ffff888102953340 RCX: 0000000000000000 [ 0.919559] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 [ 0.919908] RBP: ffff888102952180 R08: 0000000000000000 R09: 0000000000000000 [ 0.920289] R10: ffff8881043a0000 R11: 0000000000000000 R12: ffff888102952000 [ 0.920648] R13: ffff888102952180 R14: ffff8881043a0ad8 R15: ffff8881043a0880 [ 0.921014] FS: 000000002a1a0380(0000) GS:ffff888196d8d000(0000) knlGS:0000000000000000 [ 0.921424] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 0.921710] CR2: 0000000000000000 CR3: 0000000102993002 CR4: 0000000000772ef0 [ 0.922097] PKRU: 55555554 [ 0.922240] Kernel panic - not syncing: Fatal exception [ 0.922590] Kernel Offset: disabled Fixes: 0545a30 ("pkt_sched: QFQ - quick fair queue scheduler") Signed-off-by: Xiang Mei <xmei5@asu.edu> Link: https://patch.msgid.link/20260106034100.1780779-1-xmei5@asu.edu Signed-off-by: Jakub Kicinski <kuba@kernel.org>
krishnachaitanya-linux
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Feb 24, 2026
The GPIO controller is configured as non-sleeping but it uses generic
pinctrl helpers which use a mutex for synchronization.
This can cause the following lockdep splat with shared GPIOs enabled on
boards which have multiple devices using the same GPIO:
BUG: sleeping function called from invalid context at
kernel/locking/mutex.c:591
in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 12, name:
kworker/u16:0
preempt_count: 1, expected: 0
RCU nest depth: 0, expected: 0
6 locks held by kworker/u16:0/12:
#0: ffff0001f0018d48 ((wq_completion)events_unbound#2){+.+.}-{0:0},
at: process_one_work+0x18c/0x604
#1: ffff8000842dbdf0 (deferred_probe_work){+.+.}-{0:0}, at:
process_one_work+0x1b4/0x604
#2: ffff0001f18498f8 (&dev->mutex){....}-{4:4}, at:
__device_attach+0x38/0x1b0
#3: ffff0001f75f1e90 (&gdev->srcu){.+.?}-{0:0}, at:
gpiod_direction_output_raw_commit+0x0/0x360
#4: ffff0001f46e3db8 (&shared_desc->spinlock){....}-{3:3}, at:
gpio_shared_proxy_direction_output+0xd0/0x144 [gpio_shared_proxy]
#5: ffff0001f180ee90 (&gdev->srcu){.+.?}-{0:0}, at:
gpiod_direction_output_raw_commit+0x0/0x360
irq event stamp: 81450
hardirqs last enabled at (81449): [<ffff8000813acba4>]
_raw_spin_unlock_irqrestore+0x74/0x78
hardirqs last disabled at (81450): [<ffff8000813abfb8>]
_raw_spin_lock_irqsave+0x84/0x88
softirqs last enabled at (79616): [<ffff8000811455fc>]
__alloc_skb+0x17c/0x1e8
softirqs last disabled at (79614): [<ffff8000811455fc>]
__alloc_skb+0x17c/0x1e8
CPU: 2 UID: 0 PID: 12 Comm: kworker/u16:0 Not tainted
6.19.0-rc4-next-20260105+ #11975 PREEMPT
Hardware name: Hardkernel ODROID-M1 (DT)
Workqueue: events_unbound deferred_probe_work_func
Call trace:
show_stack+0x18/0x24 (C)
dump_stack_lvl+0x90/0xd0
dump_stack+0x18/0x24
__might_resched+0x144/0x248
__might_sleep+0x48/0x98
__mutex_lock+0x5c/0x894
mutex_lock_nested+0x24/0x30
pinctrl_get_device_gpio_range+0x44/0x128
pinctrl_gpio_direction+0x3c/0xe0
pinctrl_gpio_direction_output+0x14/0x20
rockchip_gpio_direction_output+0xb8/0x19c
gpiochip_direction_output+0x38/0x94
gpiod_direction_output_raw_commit+0x1d8/0x360
gpiod_direction_output_nonotify+0x7c/0x230
gpiod_direction_output+0x34/0xf8
gpio_shared_proxy_direction_output+0xec/0x144 [gpio_shared_proxy]
gpiochip_direction_output+0x38/0x94
gpiod_direction_output_raw_commit+0x1d8/0x360
gpiod_direction_output_nonotify+0x7c/0x230
gpiod_configure_flags+0xbc/0x480
gpiod_find_and_request+0x1a0/0x574
gpiod_get_index+0x58/0x84
devm_gpiod_get_index+0x20/0xb4
devm_gpiod_get_optional+0x18/0x30
rockchip_pcie_probe+0x98/0x380
platform_probe+0x5c/0xac
really_probe+0xbc/0x298
Fixes: 936ee26 ("gpio/rockchip: add driver for rockchip gpio")
Cc: stable@vger.kernel.org
Reported-by: Marek Szyprowski <m.szyprowski@samsung.com>
Closes: https://lore.kernel.org/all/d035fc29-3b03-4cd6-b8ec-001f93540bc6@samsung.com/
Acked-by: Heiko Stuebner <heiko@sntech.de>
Link: https://lore.kernel.org/r/20260106090011.21603-1-bartosz.golaszewski@oss.qualcomm.com
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
krishnachaitanya-linux
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Feb 24, 2026
…ked_inode() In btrfs_read_locked_inode() we are calling btrfs_init_file_extent_tree() while holding a path with a read locked leaf from a subvolume tree, and btrfs_init_file_extent_tree() may do a GFP_KERNEL allocation, which can trigger reclaim. This can create a circular lock dependency which lockdep warns about with the following splat: [6.1433] ====================================================== [6.1574] WARNING: possible circular locking dependency detected [6.1583] 6.18.0+ #4 Tainted: G U [6.1591] ------------------------------------------------------ [6.1599] kswapd0/117 is trying to acquire lock: [6.1606] ffff8d9b6333c5b8 (&delayed_node->mutex){+.+.}-{3:3}, at: __btrfs_release_delayed_node.part.0+0x39/0x2f0 [6.1625] but task is already holding lock: [6.1633] ffffffffa4ab8ce0 (fs_reclaim){+.+.}-{0:0}, at: balance_pgdat+0x195/0xc60 [6.1646] which lock already depends on the new lock. [6.1657] the existing dependency chain (in reverse order) is: [6.1667] -> #2 (fs_reclaim){+.+.}-{0:0}: [6.1677] fs_reclaim_acquire+0x9d/0xd0 [6.1685] __kmalloc_cache_noprof+0x59/0x750 [6.1694] btrfs_init_file_extent_tree+0x90/0x100 [6.1702] btrfs_read_locked_inode+0xc3/0x6b0 [6.1710] btrfs_iget+0xbb/0xf0 [6.1716] btrfs_lookup_dentry+0x3c5/0x8e0 [6.1724] btrfs_lookup+0x12/0x30 [6.1731] lookup_open.isra.0+0x1aa/0x6a0 [6.1739] path_openat+0x5f7/0xc60 [6.1746] do_filp_open+0xd6/0x180 [6.1753] do_sys_openat2+0x8b/0xe0 [6.1760] __x64_sys_openat+0x54/0xa0 [6.1768] do_syscall_64+0x97/0x3e0 [6.1776] entry_SYSCALL_64_after_hwframe+0x76/0x7e [6.1784] -> #1 (btrfs-tree-00){++++}-{3:3}: [6.1794] lock_release+0x127/0x2a0 [6.1801] up_read+0x1b/0x30 [6.1808] btrfs_search_slot+0x8e0/0xff0 [6.1817] btrfs_lookup_inode+0x52/0xd0 [6.1825] __btrfs_update_delayed_inode+0x73/0x520 [6.1833] btrfs_commit_inode_delayed_inode+0x11a/0x120 [6.1842] btrfs_log_inode+0x608/0x1aa0 [6.1849] btrfs_log_inode_parent+0x249/0xf80 [6.1857] btrfs_log_dentry_safe+0x3e/0x60 [6.1865] btrfs_sync_file+0x431/0x690 [6.1872] do_fsync+0x39/0x80 [6.1879] __x64_sys_fsync+0x13/0x20 [6.1887] do_syscall_64+0x97/0x3e0 [6.1894] entry_SYSCALL_64_after_hwframe+0x76/0x7e [6.1903] -> #0 (&delayed_node->mutex){+.+.}-{3:3}: [6.1913] __lock_acquire+0x15e9/0x2820 [6.1920] lock_acquire+0xc9/0x2d0 [6.1927] __mutex_lock+0xcc/0x10a0 [6.1934] __btrfs_release_delayed_node.part.0+0x39/0x2f0 [6.1944] btrfs_evict_inode+0x20b/0x4b0 [6.1952] evict+0x15a/0x2f0 [6.1958] prune_icache_sb+0x91/0xd0 [6.1966] super_cache_scan+0x150/0x1d0 [6.1974] do_shrink_slab+0x155/0x6f0 [6.1981] shrink_slab+0x48e/0x890 [6.1988] shrink_one+0x11a/0x1f0 [6.1995] shrink_node+0xbfd/0x1320 [6.1002] balance_pgdat+0x67f/0xc60 [6.1321] kswapd+0x1dc/0x3e0 [6.1643] kthread+0xff/0x240 [6.1965] ret_from_fork+0x223/0x280 [6.1287] ret_from_fork_asm+0x1a/0x30 [6.1616] other info that might help us debug this: [6.1561] Chain exists of: &delayed_node->mutex --> btrfs-tree-00 --> fs_reclaim [6.1503] Possible unsafe locking scenario: [6.1110] CPU0 CPU1 [6.1411] ---- ---- [6.1707] lock(fs_reclaim); [6.1998] lock(btrfs-tree-00); [6.1291] lock(fs_reclaim); [6.1581] lock(&delayed_node->mutex); [6.1874] *** DEADLOCK *** [6.1716] 2 locks held by kswapd0/117: [6.1999] #0: ffffffffa4ab8ce0 (fs_reclaim){+.+.}-{0:0}, at: balance_pgdat+0x195/0xc60 [6.1294] #1: ffff8d998344b0e0 (&type->s_umount_key#40){++++}- {3:3}, at: super_cache_scan+0x37/0x1d0 [6.1596] stack backtrace: [6.1183] CPU: 11 UID: 0 PID: 117 Comm: kswapd0 Tainted: G U 6.18.0+ #4 PREEMPT(lazy) [6.1185] Tainted: [U]=USER [6.1186] Hardware name: ASUS System Product Name/PRIME B560M-A AC, BIOS 2001 02/01/2023 [6.1187] Call Trace: [6.1187] <TASK> [6.1189] dump_stack_lvl+0x6e/0xa0 [6.1192] print_circular_bug.cold+0x17a/0x1c0 [6.1194] check_noncircular+0x175/0x190 [6.1197] __lock_acquire+0x15e9/0x2820 [6.1200] lock_acquire+0xc9/0x2d0 [6.1201] ? __btrfs_release_delayed_node.part.0+0x39/0x2f0 [6.1204] __mutex_lock+0xcc/0x10a0 [6.1206] ? __btrfs_release_delayed_node.part.0+0x39/0x2f0 [6.1208] ? __btrfs_release_delayed_node.part.0+0x39/0x2f0 [6.1211] ? __btrfs_release_delayed_node.part.0+0x39/0x2f0 [6.1213] __btrfs_release_delayed_node.part.0+0x39/0x2f0 [6.1215] btrfs_evict_inode+0x20b/0x4b0 [6.1217] ? lock_acquire+0xc9/0x2d0 [6.1220] evict+0x15a/0x2f0 [6.1222] prune_icache_sb+0x91/0xd0 [6.1224] super_cache_scan+0x150/0x1d0 [6.1226] do_shrink_slab+0x155/0x6f0 [6.1228] shrink_slab+0x48e/0x890 [6.1229] ? shrink_slab+0x2d2/0x890 [6.1231] shrink_one+0x11a/0x1f0 [6.1234] shrink_node+0xbfd/0x1320 [6.1236] ? shrink_node+0xa2d/0x1320 [6.1236] ? shrink_node+0xbd3/0x1320 [6.1239] ? balance_pgdat+0x67f/0xc60 [6.1239] balance_pgdat+0x67f/0xc60 [6.1241] ? finish_task_switch.isra.0+0xc4/0x2a0 [6.1246] kswapd+0x1dc/0x3e0 [6.1247] ? __pfx_autoremove_wake_function+0x10/0x10 [6.1249] ? __pfx_kswapd+0x10/0x10 [6.1250] kthread+0xff/0x240 [6.1251] ? __pfx_kthread+0x10/0x10 [6.1253] ret_from_fork+0x223/0x280 [6.1255] ? __pfx_kthread+0x10/0x10 [6.1257] ret_from_fork_asm+0x1a/0x30 [6.1260] </TASK> This is because: 1) The fsync task is holding an inode's delayed node mutex (for a directory) while calling __btrfs_update_delayed_inode() and that needs to do a search on the subvolume's btree (therefore read lock some extent buffers); 2) The lookup task, at btrfs_lookup(), triggered reclaim with the GFP_KERNEL allocation done by btrfs_init_file_extent_tree() while holding a read lock on a subvolume leaf; 3) The reclaim triggered kswapd which is doing inode eviction for the directory inode the fsync task is using as an argument to btrfs_commit_inode_delayed_inode() - but in that call chain we are trying to read lock the same leaf that the lookup task is holding while calling btrfs_init_file_extent_tree() and doing the GFP_KERNEL allocation. Fix this by calling btrfs_init_file_extent_tree() after we don't need the path anymore and release it in btrfs_read_locked_inode(). Reported-by: Thomas Hellström <thomas.hellstrom@linux.intel.com> Link: https://lore.kernel.org/linux-btrfs/6e55113a22347c3925458a5d840a18401a38b276.camel@linux.intel.com/ Fixes: 8679d26 ("btrfs: initialize inode::file_extent_tree after i_mode has been set") Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
krishnachaitanya-linux
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Feb 24, 2026
When forward-porting Rust Binder to 6.18, I neglected to take commit fb56fdf ("mm/list_lru: split the lock to per-cgroup scope") into account, and apparently I did not end up running the shrinker callback when I sanity tested the driver before submission. This leads to crashes like the following: ============================================ WARNING: possible recursive locking detected 6.18.0-mainline-maybe-dirty #1 Tainted: G IO -------------------------------------------- kswapd0/68 is trying to acquire lock: ffff956000fa18b0 (&l->lock){+.+.}-{2:2}, at: lock_list_lru_of_memcg+0x128/0x230 but task is already holding lock: ffff956000fa18b0 (&l->lock){+.+.}-{2:2}, at: rust_helper_spin_lock+0xd/0x20 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&l->lock); lock(&l->lock); *** DEADLOCK *** May be due to missing lock nesting notation 3 locks held by kswapd0/68: #0: ffffffff90d2e260 (fs_reclaim){+.+.}-{0:0}, at: kswapd+0x597/0x1160 #1: ffff956000fa18b0 (&l->lock){+.+.}-{2:2}, at: rust_helper_spin_lock+0xd/0x20 #2: ffffffff90cf3680 (rcu_read_lock){....}-{1:2}, at: lock_list_lru_of_memcg+0x2d/0x230 To fix this, remove the spin_lock() call from rust_shrink_free_page(). Cc: stable <stable@kernel.org> Fixes: eafedbc ("rust_binder: add Rust Binder driver") Signed-off-by: Alice Ryhl <aliceryhl@google.com> Link: https://patch.msgid.link/20251202-binder-shrink-unspin-v1-1-263efb9ad625@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
krishnachaitanya-linux
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Feb 24, 2026
During device unmapping (triggered by module unload or explicit unmap), a refcount underflow occurs causing a use-after-free warning: [14747.574913] ------------[ cut here ]------------ [14747.574916] refcount_t: underflow; use-after-free. [14747.574917] WARNING: lib/refcount.c:28 at refcount_warn_saturate+0x55/0x90, CPU#9: kworker/9:1/378 [14747.574924] Modules linked in: rnbd_client(-) rtrs_client rnbd_server rtrs_server rtrs_core ... [14747.574998] CPU: 9 UID: 0 PID: 378 Comm: kworker/9:1 Tainted: G O N 6.19.0-rc3lblk-fnext+ #42 PREEMPT(voluntary) [14747.575005] Workqueue: rnbd_clt_wq unmap_device_work [rnbd_client] [14747.575010] RIP: 0010:refcount_warn_saturate+0x55/0x90 [14747.575037] Call Trace: [14747.575038] <TASK> [14747.575038] rnbd_clt_unmap_device+0x170/0x1d0 [rnbd_client] [14747.575044] process_one_work+0x211/0x600 [14747.575052] worker_thread+0x184/0x330 [14747.575055] ? __pfx_worker_thread+0x10/0x10 [14747.575058] kthread+0x10d/0x250 [14747.575062] ? __pfx_kthread+0x10/0x10 [14747.575066] ret_from_fork+0x319/0x390 [14747.575069] ? __pfx_kthread+0x10/0x10 [14747.575072] ret_from_fork_asm+0x1a/0x30 [14747.575083] </TASK> [14747.575096] ---[ end trace 0000000000000000 ]--- Befor this patch :- The bug is a double kobject_put() on dev->kobj during device cleanup. Kobject Lifecycle: kobject_init_and_add() sets kobj.kref = 1 (initialization) kobject_put() sets kobj.kref = 0 (should be called once) * Before this patch: rnbd_clt_unmap_device() rnbd_destroy_sysfs() kobject_del(&dev->kobj) [remove from sysfs] kobject_put(&dev->kobj) PUT #1 (WRONG!) kref: 1 to 0 rnbd_dev_release() kfree(dev) [DEVICE FREED!] rnbd_destroy_gen_disk() [use-after-free!] rnbd_clt_put_dev() refcount_dec_and_test(&dev->refcount) kobject_put(&dev->kobj) PUT #2 (UNDERFLOW!) kref: 0 to -1 [WARNING!] The first kobject_put() in rnbd_destroy_sysfs() prematurely frees the device via rnbd_dev_release(), then the second kobject_put() in rnbd_clt_put_dev() causes refcount underflow. * After this patch :- Remove kobject_put() from rnbd_destroy_sysfs(). This function should only remove sysfs visibility (kobject_del), not manage object lifetime. Call Graph (FIXED): rnbd_clt_unmap_device() rnbd_destroy_sysfs() kobject_del(&dev->kobj) [remove from sysfs only] [kref unchanged: 1] rnbd_destroy_gen_disk() [device still valid] rnbd_clt_put_dev() refcount_dec_and_test(&dev->refcount) kobject_put(&dev->kobj) ONLY PUT (CORRECT!) kref: 1 to 0 [BALANCED] rnbd_dev_release() kfree(dev) [CLEAN DESTRUCTION] This follows the kernel pattern where sysfs removal (kobject_del) is separate from object destruction (kobject_put). Fixes: 581cf83 ("block: rnbd: add .release to rnbd_dev_ktype") Signed-off-by: Chaitanya Kulkarni <ckulkarnilinux@gmail.com> Acked-by: Jack Wang <jinpu.wang@ionos.com> Reviewed-by: Jack Wang <jinpu.wang@ionos.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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