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Hi @rokicmar!

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@busy-waiting busy-waiting changed the title Merge pull request #1 from torvalds/master . May 29, 2018
fengguang pushed a commit to 0day-ci/linux that referenced this pull request Oct 22, 2018
We were iterating a block group's free space cache rbtree without locking
first the lock that protects it (the free_space_ctl->free_space_offset
rbtree is protected by the free_space_ctl->tree_lock spinlock).

KASAN reported an use-after-free problem when iterating such a rbtree due
to a concurrent rbtree delete:

[ 9520.359168] ==================================================================
[ 9520.359656] BUG: KASAN: use-after-free in rb_next+0x13/0x90
[ 9520.359949] Read of size 8 at addr ffff8800b7ada500 by task btrfs-transacti/1721
[ 9520.360357]
[ 9520.360530] CPU: 4 PID: 1721 Comm: btrfs-transacti Tainted: G             L    4.19.0-rc8-nbor torvalds#555
[ 9520.360990] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014
[ 9520.362682] Call Trace:
[ 9520.362887]  dump_stack+0xa4/0xf5
[ 9520.363146]  print_address_description+0x78/0x280
[ 9520.363412]  kasan_report+0x263/0x390
[ 9520.363650]  ? rb_next+0x13/0x90
[ 9520.363873]  __asan_load8+0x54/0x90
[ 9520.364102]  rb_next+0x13/0x90
[ 9520.364380]  btrfs_dump_free_space+0x146/0x160 [btrfs]
[ 9520.364697]  dump_space_info+0x2cd/0x310 [btrfs]
[ 9520.364997]  btrfs_reserve_extent+0x1ee/0x1f0 [btrfs]
[ 9520.365310]  __btrfs_prealloc_file_range+0x1cc/0x620 [btrfs]
[ 9520.365646]  ? btrfs_update_time+0x180/0x180 [btrfs]
[ 9520.365923]  ? _raw_spin_unlock+0x27/0x40
[ 9520.366204]  ? btrfs_alloc_data_chunk_ondemand+0x2c0/0x5c0 [btrfs]
[ 9520.366549]  btrfs_prealloc_file_range_trans+0x23/0x30 [btrfs]
[ 9520.366880]  cache_save_setup+0x42e/0x580 [btrfs]
[ 9520.367220]  ? btrfs_check_data_free_space+0xd0/0xd0 [btrfs]
[ 9520.367518]  ? lock_downgrade+0x2f0/0x2f0
[ 9520.367799]  ? btrfs_write_dirty_block_groups+0x11f/0x6e0 [btrfs]
[ 9520.368104]  ? kasan_check_read+0x11/0x20
[ 9520.368349]  ? do_raw_spin_unlock+0xa8/0x140
[ 9520.368638]  btrfs_write_dirty_block_groups+0x2af/0x6e0 [btrfs]
[ 9520.368978]  ? btrfs_start_dirty_block_groups+0x870/0x870 [btrfs]
[ 9520.369282]  ? do_raw_spin_unlock+0xa8/0x140
[ 9520.369534]  ? _raw_spin_unlock+0x27/0x40
[ 9520.369811]  ? btrfs_run_delayed_refs+0x1b8/0x230 [btrfs]
[ 9520.370137]  commit_cowonly_roots+0x4b9/0x610 [btrfs]
[ 9520.370560]  ? commit_fs_roots+0x350/0x350 [btrfs]
[ 9520.370926]  ? btrfs_run_delayed_refs+0x1b8/0x230 [btrfs]
[ 9520.371285]  btrfs_commit_transaction+0x5e5/0x10e0 [btrfs]
[ 9520.371612]  ? btrfs_apply_pending_changes+0x90/0x90 [btrfs]
[ 9520.371943]  ? start_transaction+0x168/0x6c0 [btrfs]
[ 9520.372257]  transaction_kthread+0x21c/0x240 [btrfs]
[ 9520.372537]  kthread+0x1d2/0x1f0
[ 9520.372793]  ? btrfs_cleanup_transaction+0xb50/0xb50 [btrfs]
[ 9520.373090]  ? kthread_park+0xb0/0xb0
[ 9520.373329]  ret_from_fork+0x3a/0x50
[ 9520.373567]
[ 9520.373738] Allocated by task 1804:
[ 9520.373974]  kasan_kmalloc+0xff/0x180
[ 9520.374208]  kasan_slab_alloc+0x11/0x20
[ 9520.374447]  kmem_cache_alloc+0xfc/0x2d0
[ 9520.374731]  __btrfs_add_free_space+0x40/0x580 [btrfs]
[ 9520.375044]  unpin_extent_range+0x4f7/0x7a0 [btrfs]
[ 9520.375383]  btrfs_finish_extent_commit+0x15f/0x4d0 [btrfs]
[ 9520.375707]  btrfs_commit_transaction+0xb06/0x10e0 [btrfs]
[ 9520.376027]  btrfs_alloc_data_chunk_ondemand+0x237/0x5c0 [btrfs]
[ 9520.376365]  btrfs_check_data_free_space+0x81/0xd0 [btrfs]
[ 9520.376689]  btrfs_delalloc_reserve_space+0x25/0x80 [btrfs]
[ 9520.377018]  btrfs_direct_IO+0x42e/0x6d0 [btrfs]
[ 9520.377284]  generic_file_direct_write+0x11e/0x220
[ 9520.377587]  btrfs_file_write_iter+0x472/0xac0 [btrfs]
[ 9520.377875]  aio_write+0x25c/0x360
[ 9520.378106]  io_submit_one+0xaa0/0xdc0
[ 9520.378343]  __se_sys_io_submit+0xfa/0x2f0
[ 9520.378589]  __x64_sys_io_submit+0x43/0x50
[ 9520.378840]  do_syscall_64+0x7d/0x240
[ 9520.379081]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
[ 9520.379387]
[ 9520.379557] Freed by task 1802:
[ 9520.379782]  __kasan_slab_free+0x173/0x260
[ 9520.380028]  kasan_slab_free+0xe/0x10
[ 9520.380262]  kmem_cache_free+0xc1/0x2c0
[ 9520.380544]  btrfs_find_space_for_alloc+0x4cd/0x4e0 [btrfs]
[ 9520.380866]  find_free_extent+0xa99/0x17e0 [btrfs]
[ 9520.381166]  btrfs_reserve_extent+0xd5/0x1f0 [btrfs]
[ 9520.381474]  btrfs_get_blocks_direct+0x60b/0xbd0 [btrfs]
[ 9520.381761]  __blockdev_direct_IO+0x10ee/0x58a1
[ 9520.382059]  btrfs_direct_IO+0x25a/0x6d0 [btrfs]
[ 9520.382321]  generic_file_direct_write+0x11e/0x220
[ 9520.382623]  btrfs_file_write_iter+0x472/0xac0 [btrfs]
[ 9520.382904]  aio_write+0x25c/0x360
[ 9520.383172]  io_submit_one+0xaa0/0xdc0
[ 9520.383416]  __se_sys_io_submit+0xfa/0x2f0
[ 9520.383678]  __x64_sys_io_submit+0x43/0x50
[ 9520.383927]  do_syscall_64+0x7d/0x240
[ 9520.384165]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
[ 9520.384439]
[ 9520.384610] The buggy address belongs to the object at ffff8800b7ada500
                which belongs to the cache btrfs_free_space of size 72
[ 9520.385175] The buggy address is located 0 bytes inside of
                72-byte region [ffff8800b7ada500, ffff8800b7ada548)
[ 9520.385691] The buggy address belongs to the page:
[ 9520.385957] page:ffffea0002deb680 count:1 mapcount:0 mapping:ffff880108a1d700 index:0x0 compound_mapcount: 0
[ 9520.388030] flags: 0x8100(slab|head)
[ 9520.388281] raw: 0000000000008100 ffffea0002deb608 ffffea0002728808 ffff880108a1d700
[ 9520.388722] raw: 0000000000000000 0000000000130013 00000001ffffffff 0000000000000000
[ 9520.389169] page dumped because: kasan: bad access detected
[ 9520.389473]
[ 9520.389658] Memory state around the buggy address:
[ 9520.389943]  ffff8800b7ada400: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[ 9520.390368]  ffff8800b7ada480: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[ 9520.390796] >ffff8800b7ada500: fb fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc
[ 9520.391223]                    ^
[ 9520.391461]  ffff8800b7ada580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[ 9520.391885]  ffff8800b7ada600: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[ 9520.392313] ==================================================================
[ 9520.392772] BTRFS critical (device vdc): entry offset 2258497536, bytes 131072, bitmap no
[ 9520.393247] BUG: unable to handle kernel NULL pointer dereference at 0000000000000011
[ 9520.393705] PGD 800000010dbab067 P4D 800000010dbab067 PUD 107551067 PMD 0
[ 9520.394059] Oops: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN PTI
[ 9520.394378] CPU: 4 PID: 1721 Comm: btrfs-transacti Tainted: G    B        L    4.19.0-rc8-nbor torvalds#555
[ 9520.394858] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014
[ 9520.395350] RIP: 0010:rb_next+0x3c/0x90
[ 9520.396461] RSP: 0018:ffff8801074ff780 EFLAGS: 00010292
[ 9520.396762] RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffffffff81b5ac4c
[ 9520.397115] RDX: 0000000000000000 RSI: 0000000000000008 RDI: 0000000000000011
[ 9520.397468] RBP: ffff8801074ff7a0 R08: ffffed0021d64ccc R09: ffffed0021d64ccc
[ 9520.397821] R10: 0000000000000001 R11: ffffed0021d64ccb R12: ffff8800b91e0000
[ 9520.398188] R13: ffff8800a3ceba48 R14: ffff8800b627bf80 R15: 0000000000020000
[ 9520.398555] FS:  0000000000000000(0000) GS:ffff88010eb00000(0000) knlGS:0000000000000000
[ 9520.399007] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 9520.399335] CR2: 0000000000000011 CR3: 0000000106b52000 CR4: 00000000000006a0
[ 9520.399679] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 9520.400023] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 9520.400400] Call Trace:
[ 9520.400648]  btrfs_dump_free_space+0x146/0x160 [btrfs]
[ 9520.400974]  dump_space_info+0x2cd/0x310 [btrfs]
[ 9520.401287]  btrfs_reserve_extent+0x1ee/0x1f0 [btrfs]
[ 9520.401609]  __btrfs_prealloc_file_range+0x1cc/0x620 [btrfs]
[ 9520.401952]  ? btrfs_update_time+0x180/0x180 [btrfs]
[ 9520.402232]  ? _raw_spin_unlock+0x27/0x40
[ 9520.402522]  ? btrfs_alloc_data_chunk_ondemand+0x2c0/0x5c0 [btrfs]
[ 9520.402882]  btrfs_prealloc_file_range_trans+0x23/0x30 [btrfs]
[ 9520.403261]  cache_save_setup+0x42e/0x580 [btrfs]
[ 9520.403570]  ? btrfs_check_data_free_space+0xd0/0xd0 [btrfs]
[ 9520.403871]  ? lock_downgrade+0x2f0/0x2f0
[ 9520.404161]  ? btrfs_write_dirty_block_groups+0x11f/0x6e0 [btrfs]
[ 9520.404481]  ? kasan_check_read+0x11/0x20
[ 9520.404732]  ? do_raw_spin_unlock+0xa8/0x140
[ 9520.405026]  btrfs_write_dirty_block_groups+0x2af/0x6e0 [btrfs]
[ 9520.405375]  ? btrfs_start_dirty_block_groups+0x870/0x870 [btrfs]
[ 9520.405694]  ? do_raw_spin_unlock+0xa8/0x140
[ 9520.405958]  ? _raw_spin_unlock+0x27/0x40
[ 9520.406243]  ? btrfs_run_delayed_refs+0x1b8/0x230 [btrfs]
[ 9520.406574]  commit_cowonly_roots+0x4b9/0x610 [btrfs]
[ 9520.406899]  ? commit_fs_roots+0x350/0x350 [btrfs]
[ 9520.407253]  ? btrfs_run_delayed_refs+0x1b8/0x230 [btrfs]
[ 9520.407589]  btrfs_commit_transaction+0x5e5/0x10e0 [btrfs]
[ 9520.407925]  ? btrfs_apply_pending_changes+0x90/0x90 [btrfs]
[ 9520.408262]  ? start_transaction+0x168/0x6c0 [btrfs]
[ 9520.408582]  transaction_kthread+0x21c/0x240 [btrfs]
[ 9520.408870]  kthread+0x1d2/0x1f0
[ 9520.409138]  ? btrfs_cleanup_transaction+0xb50/0xb50 [btrfs]
[ 9520.409440]  ? kthread_park+0xb0/0xb0
[ 9520.409682]  ret_from_fork+0x3a/0x50
[ 9520.410508] Dumping ftrace buffer:
[ 9520.410764]    (ftrace buffer empty)
[ 9520.411007] CR2: 0000000000000011
[ 9520.411297] ---[ end trace 01a0863445cf360a ]---
[ 9520.411568] RIP: 0010:rb_next+0x3c/0x90
[ 9520.412644] RSP: 0018:ffff8801074ff780 EFLAGS: 00010292
[ 9520.412932] RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffffffff81b5ac4c
[ 9520.413274] RDX: 0000000000000000 RSI: 0000000000000008 RDI: 0000000000000011
[ 9520.413616] RBP: ffff8801074ff7a0 R08: ffffed0021d64ccc R09: ffffed0021d64ccc
[ 9520.414007] R10: 0000000000000001 R11: ffffed0021d64ccb R12: ffff8800b91e0000
[ 9520.414349] R13: ffff8800a3ceba48 R14: ffff8800b627bf80 R15: 0000000000020000
[ 9520.416074] FS:  0000000000000000(0000) GS:ffff88010eb00000(0000) knlGS:0000000000000000
[ 9520.416536] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 9520.416848] CR2: 0000000000000011 CR3: 0000000106b52000 CR4: 00000000000006a0
[ 9520.418477] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 9520.418846] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 9520.419204] Kernel panic - not syncing: Fatal exception
[ 9520.419666] Dumping ftrace buffer:
[ 9520.419930]    (ftrace buffer empty)
[ 9520.420168] Kernel Offset: disabled
[ 9520.420406] ---[ end Kernel panic - not syncing: Fatal exception ]---

Fix this by acquiring the respective lock before iterating the rbtree.

Reported-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
kdave pushed a commit to kdave/btrfs-devel that referenced this pull request Oct 25, 2018
We were iterating a block group's free space cache rbtree without locking
first the lock that protects it (the free_space_ctl->free_space_offset
rbtree is protected by the free_space_ctl->tree_lock spinlock).

KASAN reported an use-after-free problem when iterating such a rbtree due
to a concurrent rbtree delete:

[ 9520.359168] ==================================================================
[ 9520.359656] BUG: KASAN: use-after-free in rb_next+0x13/0x90
[ 9520.359949] Read of size 8 at addr ffff8800b7ada500 by task btrfs-transacti/1721
[ 9520.360357]
[ 9520.360530] CPU: 4 PID: 1721 Comm: btrfs-transacti Tainted: G             L    4.19.0-rc8-nbor torvalds#555
[ 9520.360990] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014
[ 9520.362682] Call Trace:
[ 9520.362887]  dump_stack+0xa4/0xf5
[ 9520.363146]  print_address_description+0x78/0x280
[ 9520.363412]  kasan_report+0x263/0x390
[ 9520.363650]  ? rb_next+0x13/0x90
[ 9520.363873]  __asan_load8+0x54/0x90
[ 9520.364102]  rb_next+0x13/0x90
[ 9520.364380]  btrfs_dump_free_space+0x146/0x160 [btrfs]
[ 9520.364697]  dump_space_info+0x2cd/0x310 [btrfs]
[ 9520.364997]  btrfs_reserve_extent+0x1ee/0x1f0 [btrfs]
[ 9520.365310]  __btrfs_prealloc_file_range+0x1cc/0x620 [btrfs]
[ 9520.365646]  ? btrfs_update_time+0x180/0x180 [btrfs]
[ 9520.365923]  ? _raw_spin_unlock+0x27/0x40
[ 9520.366204]  ? btrfs_alloc_data_chunk_ondemand+0x2c0/0x5c0 [btrfs]
[ 9520.366549]  btrfs_prealloc_file_range_trans+0x23/0x30 [btrfs]
[ 9520.366880]  cache_save_setup+0x42e/0x580 [btrfs]
[ 9520.367220]  ? btrfs_check_data_free_space+0xd0/0xd0 [btrfs]
[ 9520.367518]  ? lock_downgrade+0x2f0/0x2f0
[ 9520.367799]  ? btrfs_write_dirty_block_groups+0x11f/0x6e0 [btrfs]
[ 9520.368104]  ? kasan_check_read+0x11/0x20
[ 9520.368349]  ? do_raw_spin_unlock+0xa8/0x140
[ 9520.368638]  btrfs_write_dirty_block_groups+0x2af/0x6e0 [btrfs]
[ 9520.368978]  ? btrfs_start_dirty_block_groups+0x870/0x870 [btrfs]
[ 9520.369282]  ? do_raw_spin_unlock+0xa8/0x140
[ 9520.369534]  ? _raw_spin_unlock+0x27/0x40
[ 9520.369811]  ? btrfs_run_delayed_refs+0x1b8/0x230 [btrfs]
[ 9520.370137]  commit_cowonly_roots+0x4b9/0x610 [btrfs]
[ 9520.370560]  ? commit_fs_roots+0x350/0x350 [btrfs]
[ 9520.370926]  ? btrfs_run_delayed_refs+0x1b8/0x230 [btrfs]
[ 9520.371285]  btrfs_commit_transaction+0x5e5/0x10e0 [btrfs]
[ 9520.371612]  ? btrfs_apply_pending_changes+0x90/0x90 [btrfs]
[ 9520.371943]  ? start_transaction+0x168/0x6c0 [btrfs]
[ 9520.372257]  transaction_kthread+0x21c/0x240 [btrfs]
[ 9520.372537]  kthread+0x1d2/0x1f0
[ 9520.372793]  ? btrfs_cleanup_transaction+0xb50/0xb50 [btrfs]
[ 9520.373090]  ? kthread_park+0xb0/0xb0
[ 9520.373329]  ret_from_fork+0x3a/0x50
[ 9520.373567]
[ 9520.373738] Allocated by task 1804:
[ 9520.373974]  kasan_kmalloc+0xff/0x180
[ 9520.374208]  kasan_slab_alloc+0x11/0x20
[ 9520.374447]  kmem_cache_alloc+0xfc/0x2d0
[ 9520.374731]  __btrfs_add_free_space+0x40/0x580 [btrfs]
[ 9520.375044]  unpin_extent_range+0x4f7/0x7a0 [btrfs]
[ 9520.375383]  btrfs_finish_extent_commit+0x15f/0x4d0 [btrfs]
[ 9520.375707]  btrfs_commit_transaction+0xb06/0x10e0 [btrfs]
[ 9520.376027]  btrfs_alloc_data_chunk_ondemand+0x237/0x5c0 [btrfs]
[ 9520.376365]  btrfs_check_data_free_space+0x81/0xd0 [btrfs]
[ 9520.376689]  btrfs_delalloc_reserve_space+0x25/0x80 [btrfs]
[ 9520.377018]  btrfs_direct_IO+0x42e/0x6d0 [btrfs]
[ 9520.377284]  generic_file_direct_write+0x11e/0x220
[ 9520.377587]  btrfs_file_write_iter+0x472/0xac0 [btrfs]
[ 9520.377875]  aio_write+0x25c/0x360
[ 9520.378106]  io_submit_one+0xaa0/0xdc0
[ 9520.378343]  __se_sys_io_submit+0xfa/0x2f0
[ 9520.378589]  __x64_sys_io_submit+0x43/0x50
[ 9520.378840]  do_syscall_64+0x7d/0x240
[ 9520.379081]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
[ 9520.379387]
[ 9520.379557] Freed by task 1802:
[ 9520.379782]  __kasan_slab_free+0x173/0x260
[ 9520.380028]  kasan_slab_free+0xe/0x10
[ 9520.380262]  kmem_cache_free+0xc1/0x2c0
[ 9520.380544]  btrfs_find_space_for_alloc+0x4cd/0x4e0 [btrfs]
[ 9520.380866]  find_free_extent+0xa99/0x17e0 [btrfs]
[ 9520.381166]  btrfs_reserve_extent+0xd5/0x1f0 [btrfs]
[ 9520.381474]  btrfs_get_blocks_direct+0x60b/0xbd0 [btrfs]
[ 9520.381761]  __blockdev_direct_IO+0x10ee/0x58a1
[ 9520.382059]  btrfs_direct_IO+0x25a/0x6d0 [btrfs]
[ 9520.382321]  generic_file_direct_write+0x11e/0x220
[ 9520.382623]  btrfs_file_write_iter+0x472/0xac0 [btrfs]
[ 9520.382904]  aio_write+0x25c/0x360
[ 9520.383172]  io_submit_one+0xaa0/0xdc0
[ 9520.383416]  __se_sys_io_submit+0xfa/0x2f0
[ 9520.383678]  __x64_sys_io_submit+0x43/0x50
[ 9520.383927]  do_syscall_64+0x7d/0x240
[ 9520.384165]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
[ 9520.384439]
[ 9520.384610] The buggy address belongs to the object at ffff8800b7ada500
                which belongs to the cache btrfs_free_space of size 72
[ 9520.385175] The buggy address is located 0 bytes inside of
                72-byte region [ffff8800b7ada500, ffff8800b7ada548)
[ 9520.385691] The buggy address belongs to the page:
[ 9520.385957] page:ffffea0002deb680 count:1 mapcount:0 mapping:ffff880108a1d700 index:0x0 compound_mapcount: 0
[ 9520.388030] flags: 0x8100(slab|head)
[ 9520.388281] raw: 0000000000008100 ffffea0002deb608 ffffea0002728808 ffff880108a1d700
[ 9520.388722] raw: 0000000000000000 0000000000130013 00000001ffffffff 0000000000000000
[ 9520.389169] page dumped because: kasan: bad access detected
[ 9520.389473]
[ 9520.389658] Memory state around the buggy address:
[ 9520.389943]  ffff8800b7ada400: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[ 9520.390368]  ffff8800b7ada480: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[ 9520.390796] >ffff8800b7ada500: fb fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc
[ 9520.391223]                    ^
[ 9520.391461]  ffff8800b7ada580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[ 9520.391885]  ffff8800b7ada600: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[ 9520.392313] ==================================================================
[ 9520.392772] BTRFS critical (device vdc): entry offset 2258497536, bytes 131072, bitmap no
[ 9520.393247] BUG: unable to handle kernel NULL pointer dereference at 0000000000000011
[ 9520.393705] PGD 800000010dbab067 P4D 800000010dbab067 PUD 107551067 PMD 0
[ 9520.394059] Oops: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN PTI
[ 9520.394378] CPU: 4 PID: 1721 Comm: btrfs-transacti Tainted: G    B        L    4.19.0-rc8-nbor torvalds#555
[ 9520.394858] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014
[ 9520.395350] RIP: 0010:rb_next+0x3c/0x90
[ 9520.396461] RSP: 0018:ffff8801074ff780 EFLAGS: 00010292
[ 9520.396762] RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffffffff81b5ac4c
[ 9520.397115] RDX: 0000000000000000 RSI: 0000000000000008 RDI: 0000000000000011
[ 9520.397468] RBP: ffff8801074ff7a0 R08: ffffed0021d64ccc R09: ffffed0021d64ccc
[ 9520.397821] R10: 0000000000000001 R11: ffffed0021d64ccb R12: ffff8800b91e0000
[ 9520.398188] R13: ffff8800a3ceba48 R14: ffff8800b627bf80 R15: 0000000000020000
[ 9520.398555] FS:  0000000000000000(0000) GS:ffff88010eb00000(0000) knlGS:0000000000000000
[ 9520.399007] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 9520.399335] CR2: 0000000000000011 CR3: 0000000106b52000 CR4: 00000000000006a0
[ 9520.399679] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 9520.400023] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 9520.400400] Call Trace:
[ 9520.400648]  btrfs_dump_free_space+0x146/0x160 [btrfs]
[ 9520.400974]  dump_space_info+0x2cd/0x310 [btrfs]
[ 9520.401287]  btrfs_reserve_extent+0x1ee/0x1f0 [btrfs]
[ 9520.401609]  __btrfs_prealloc_file_range+0x1cc/0x620 [btrfs]
[ 9520.401952]  ? btrfs_update_time+0x180/0x180 [btrfs]
[ 9520.402232]  ? _raw_spin_unlock+0x27/0x40
[ 9520.402522]  ? btrfs_alloc_data_chunk_ondemand+0x2c0/0x5c0 [btrfs]
[ 9520.402882]  btrfs_prealloc_file_range_trans+0x23/0x30 [btrfs]
[ 9520.403261]  cache_save_setup+0x42e/0x580 [btrfs]
[ 9520.403570]  ? btrfs_check_data_free_space+0xd0/0xd0 [btrfs]
[ 9520.403871]  ? lock_downgrade+0x2f0/0x2f0
[ 9520.404161]  ? btrfs_write_dirty_block_groups+0x11f/0x6e0 [btrfs]
[ 9520.404481]  ? kasan_check_read+0x11/0x20
[ 9520.404732]  ? do_raw_spin_unlock+0xa8/0x140
[ 9520.405026]  btrfs_write_dirty_block_groups+0x2af/0x6e0 [btrfs]
[ 9520.405375]  ? btrfs_start_dirty_block_groups+0x870/0x870 [btrfs]
[ 9520.405694]  ? do_raw_spin_unlock+0xa8/0x140
[ 9520.405958]  ? _raw_spin_unlock+0x27/0x40
[ 9520.406243]  ? btrfs_run_delayed_refs+0x1b8/0x230 [btrfs]
[ 9520.406574]  commit_cowonly_roots+0x4b9/0x610 [btrfs]
[ 9520.406899]  ? commit_fs_roots+0x350/0x350 [btrfs]
[ 9520.407253]  ? btrfs_run_delayed_refs+0x1b8/0x230 [btrfs]
[ 9520.407589]  btrfs_commit_transaction+0x5e5/0x10e0 [btrfs]
[ 9520.407925]  ? btrfs_apply_pending_changes+0x90/0x90 [btrfs]
[ 9520.408262]  ? start_transaction+0x168/0x6c0 [btrfs]
[ 9520.408582]  transaction_kthread+0x21c/0x240 [btrfs]
[ 9520.408870]  kthread+0x1d2/0x1f0
[ 9520.409138]  ? btrfs_cleanup_transaction+0xb50/0xb50 [btrfs]
[ 9520.409440]  ? kthread_park+0xb0/0xb0
[ 9520.409682]  ret_from_fork+0x3a/0x50
[ 9520.410508] Dumping ftrace buffer:
[ 9520.410764]    (ftrace buffer empty)
[ 9520.411007] CR2: 0000000000000011
[ 9520.411297] ---[ end trace 01a0863445cf360a ]---
[ 9520.411568] RIP: 0010:rb_next+0x3c/0x90
[ 9520.412644] RSP: 0018:ffff8801074ff780 EFLAGS: 00010292
[ 9520.412932] RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffffffff81b5ac4c
[ 9520.413274] RDX: 0000000000000000 RSI: 0000000000000008 RDI: 0000000000000011
[ 9520.413616] RBP: ffff8801074ff7a0 R08: ffffed0021d64ccc R09: ffffed0021d64ccc
[ 9520.414007] R10: 0000000000000001 R11: ffffed0021d64ccb R12: ffff8800b91e0000
[ 9520.414349] R13: ffff8800a3ceba48 R14: ffff8800b627bf80 R15: 0000000000020000
[ 9520.416074] FS:  0000000000000000(0000) GS:ffff88010eb00000(0000) knlGS:0000000000000000
[ 9520.416536] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 9520.416848] CR2: 0000000000000011 CR3: 0000000106b52000 CR4: 00000000000006a0
[ 9520.418477] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 9520.418846] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 9520.419204] Kernel panic - not syncing: Fatal exception
[ 9520.419666] Dumping ftrace buffer:
[ 9520.419930]    (ftrace buffer empty)
[ 9520.420168] Kernel Offset: disabled
[ 9520.420406] ---[ end Kernel panic - not syncing: Fatal exception ]---

Fix this by acquiring the respective lock before iterating the rbtree.

Reported-by: Nikolay Borisov <nborisov@suse.com>
CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
frank-w referenced this pull request in frank-w/BPI-Router-Linux Nov 13, 2018
commit 9084cb6 upstream.

We were iterating a block group's free space cache rbtree without locking
first the lock that protects it (the free_space_ctl->free_space_offset
rbtree is protected by the free_space_ctl->tree_lock spinlock).

KASAN reported an use-after-free problem when iterating such a rbtree due
to a concurrent rbtree delete:

[ 9520.359168] ==================================================================
[ 9520.359656] BUG: KASAN: use-after-free in rb_next+0x13/0x90
[ 9520.359949] Read of size 8 at addr ffff8800b7ada500 by task btrfs-transacti/1721
[ 9520.360357]
[ 9520.360530] CPU: 4 PID: 1721 Comm: btrfs-transacti Tainted: G             L    4.19.0-rc8-nbor #555
[ 9520.360990] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014
[ 9520.362682] Call Trace:
[ 9520.362887]  dump_stack+0xa4/0xf5
[ 9520.363146]  print_address_description+0x78/0x280
[ 9520.363412]  kasan_report+0x263/0x390
[ 9520.363650]  ? rb_next+0x13/0x90
[ 9520.363873]  __asan_load8+0x54/0x90
[ 9520.364102]  rb_next+0x13/0x90
[ 9520.364380]  btrfs_dump_free_space+0x146/0x160 [btrfs]
[ 9520.364697]  dump_space_info+0x2cd/0x310 [btrfs]
[ 9520.364997]  btrfs_reserve_extent+0x1ee/0x1f0 [btrfs]
[ 9520.365310]  __btrfs_prealloc_file_range+0x1cc/0x620 [btrfs]
[ 9520.365646]  ? btrfs_update_time+0x180/0x180 [btrfs]
[ 9520.365923]  ? _raw_spin_unlock+0x27/0x40
[ 9520.366204]  ? btrfs_alloc_data_chunk_ondemand+0x2c0/0x5c0 [btrfs]
[ 9520.366549]  btrfs_prealloc_file_range_trans+0x23/0x30 [btrfs]
[ 9520.366880]  cache_save_setup+0x42e/0x580 [btrfs]
[ 9520.367220]  ? btrfs_check_data_free_space+0xd0/0xd0 [btrfs]
[ 9520.367518]  ? lock_downgrade+0x2f0/0x2f0
[ 9520.367799]  ? btrfs_write_dirty_block_groups+0x11f/0x6e0 [btrfs]
[ 9520.368104]  ? kasan_check_read+0x11/0x20
[ 9520.368349]  ? do_raw_spin_unlock+0xa8/0x140
[ 9520.368638]  btrfs_write_dirty_block_groups+0x2af/0x6e0 [btrfs]
[ 9520.368978]  ? btrfs_start_dirty_block_groups+0x870/0x870 [btrfs]
[ 9520.369282]  ? do_raw_spin_unlock+0xa8/0x140
[ 9520.369534]  ? _raw_spin_unlock+0x27/0x40
[ 9520.369811]  ? btrfs_run_delayed_refs+0x1b8/0x230 [btrfs]
[ 9520.370137]  commit_cowonly_roots+0x4b9/0x610 [btrfs]
[ 9520.370560]  ? commit_fs_roots+0x350/0x350 [btrfs]
[ 9520.370926]  ? btrfs_run_delayed_refs+0x1b8/0x230 [btrfs]
[ 9520.371285]  btrfs_commit_transaction+0x5e5/0x10e0 [btrfs]
[ 9520.371612]  ? btrfs_apply_pending_changes+0x90/0x90 [btrfs]
[ 9520.371943]  ? start_transaction+0x168/0x6c0 [btrfs]
[ 9520.372257]  transaction_kthread+0x21c/0x240 [btrfs]
[ 9520.372537]  kthread+0x1d2/0x1f0
[ 9520.372793]  ? btrfs_cleanup_transaction+0xb50/0xb50 [btrfs]
[ 9520.373090]  ? kthread_park+0xb0/0xb0
[ 9520.373329]  ret_from_fork+0x3a/0x50
[ 9520.373567]
[ 9520.373738] Allocated by task 1804:
[ 9520.373974]  kasan_kmalloc+0xff/0x180
[ 9520.374208]  kasan_slab_alloc+0x11/0x20
[ 9520.374447]  kmem_cache_alloc+0xfc/0x2d0
[ 9520.374731]  __btrfs_add_free_space+0x40/0x580 [btrfs]
[ 9520.375044]  unpin_extent_range+0x4f7/0x7a0 [btrfs]
[ 9520.375383]  btrfs_finish_extent_commit+0x15f/0x4d0 [btrfs]
[ 9520.375707]  btrfs_commit_transaction+0xb06/0x10e0 [btrfs]
[ 9520.376027]  btrfs_alloc_data_chunk_ondemand+0x237/0x5c0 [btrfs]
[ 9520.376365]  btrfs_check_data_free_space+0x81/0xd0 [btrfs]
[ 9520.376689]  btrfs_delalloc_reserve_space+0x25/0x80 [btrfs]
[ 9520.377018]  btrfs_direct_IO+0x42e/0x6d0 [btrfs]
[ 9520.377284]  generic_file_direct_write+0x11e/0x220
[ 9520.377587]  btrfs_file_write_iter+0x472/0xac0 [btrfs]
[ 9520.377875]  aio_write+0x25c/0x360
[ 9520.378106]  io_submit_one+0xaa0/0xdc0
[ 9520.378343]  __se_sys_io_submit+0xfa/0x2f0
[ 9520.378589]  __x64_sys_io_submit+0x43/0x50
[ 9520.378840]  do_syscall_64+0x7d/0x240
[ 9520.379081]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
[ 9520.379387]
[ 9520.379557] Freed by task 1802:
[ 9520.379782]  __kasan_slab_free+0x173/0x260
[ 9520.380028]  kasan_slab_free+0xe/0x10
[ 9520.380262]  kmem_cache_free+0xc1/0x2c0
[ 9520.380544]  btrfs_find_space_for_alloc+0x4cd/0x4e0 [btrfs]
[ 9520.380866]  find_free_extent+0xa99/0x17e0 [btrfs]
[ 9520.381166]  btrfs_reserve_extent+0xd5/0x1f0 [btrfs]
[ 9520.381474]  btrfs_get_blocks_direct+0x60b/0xbd0 [btrfs]
[ 9520.381761]  __blockdev_direct_IO+0x10ee/0x58a1
[ 9520.382059]  btrfs_direct_IO+0x25a/0x6d0 [btrfs]
[ 9520.382321]  generic_file_direct_write+0x11e/0x220
[ 9520.382623]  btrfs_file_write_iter+0x472/0xac0 [btrfs]
[ 9520.382904]  aio_write+0x25c/0x360
[ 9520.383172]  io_submit_one+0xaa0/0xdc0
[ 9520.383416]  __se_sys_io_submit+0xfa/0x2f0
[ 9520.383678]  __x64_sys_io_submit+0x43/0x50
[ 9520.383927]  do_syscall_64+0x7d/0x240
[ 9520.384165]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
[ 9520.384439]
[ 9520.384610] The buggy address belongs to the object at ffff8800b7ada500
                which belongs to the cache btrfs_free_space of size 72
[ 9520.385175] The buggy address is located 0 bytes inside of
                72-byte region [ffff8800b7ada500, ffff8800b7ada548)
[ 9520.385691] The buggy address belongs to the page:
[ 9520.385957] page:ffffea0002deb680 count:1 mapcount:0 mapping:ffff880108a1d700 index:0x0 compound_mapcount: 0
[ 9520.388030] flags: 0x8100(slab|head)
[ 9520.388281] raw: 0000000000008100 ffffea0002deb608 ffffea0002728808 ffff880108a1d700
[ 9520.388722] raw: 0000000000000000 0000000000130013 00000001ffffffff 0000000000000000
[ 9520.389169] page dumped because: kasan: bad access detected
[ 9520.389473]
[ 9520.389658] Memory state around the buggy address:
[ 9520.389943]  ffff8800b7ada400: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[ 9520.390368]  ffff8800b7ada480: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[ 9520.390796] >ffff8800b7ada500: fb fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc
[ 9520.391223]                    ^
[ 9520.391461]  ffff8800b7ada580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[ 9520.391885]  ffff8800b7ada600: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[ 9520.392313] ==================================================================
[ 9520.392772] BTRFS critical (device vdc): entry offset 2258497536, bytes 131072, bitmap no
[ 9520.393247] BUG: unable to handle kernel NULL pointer dereference at 0000000000000011
[ 9520.393705] PGD 800000010dbab067 P4D 800000010dbab067 PUD 107551067 PMD 0
[ 9520.394059] Oops: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN PTI
[ 9520.394378] CPU: 4 PID: 1721 Comm: btrfs-transacti Tainted: G    B        L    4.19.0-rc8-nbor #555
[ 9520.394858] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014
[ 9520.395350] RIP: 0010:rb_next+0x3c/0x90
[ 9520.396461] RSP: 0018:ffff8801074ff780 EFLAGS: 00010292
[ 9520.396762] RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffffffff81b5ac4c
[ 9520.397115] RDX: 0000000000000000 RSI: 0000000000000008 RDI: 0000000000000011
[ 9520.397468] RBP: ffff8801074ff7a0 R08: ffffed0021d64ccc R09: ffffed0021d64ccc
[ 9520.397821] R10: 0000000000000001 R11: ffffed0021d64ccb R12: ffff8800b91e0000
[ 9520.398188] R13: ffff8800a3ceba48 R14: ffff8800b627bf80 R15: 0000000000020000
[ 9520.398555] FS:  0000000000000000(0000) GS:ffff88010eb00000(0000) knlGS:0000000000000000
[ 9520.399007] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 9520.399335] CR2: 0000000000000011 CR3: 0000000106b52000 CR4: 00000000000006a0
[ 9520.399679] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 9520.400023] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 9520.400400] Call Trace:
[ 9520.400648]  btrfs_dump_free_space+0x146/0x160 [btrfs]
[ 9520.400974]  dump_space_info+0x2cd/0x310 [btrfs]
[ 9520.401287]  btrfs_reserve_extent+0x1ee/0x1f0 [btrfs]
[ 9520.401609]  __btrfs_prealloc_file_range+0x1cc/0x620 [btrfs]
[ 9520.401952]  ? btrfs_update_time+0x180/0x180 [btrfs]
[ 9520.402232]  ? _raw_spin_unlock+0x27/0x40
[ 9520.402522]  ? btrfs_alloc_data_chunk_ondemand+0x2c0/0x5c0 [btrfs]
[ 9520.402882]  btrfs_prealloc_file_range_trans+0x23/0x30 [btrfs]
[ 9520.403261]  cache_save_setup+0x42e/0x580 [btrfs]
[ 9520.403570]  ? btrfs_check_data_free_space+0xd0/0xd0 [btrfs]
[ 9520.403871]  ? lock_downgrade+0x2f0/0x2f0
[ 9520.404161]  ? btrfs_write_dirty_block_groups+0x11f/0x6e0 [btrfs]
[ 9520.404481]  ? kasan_check_read+0x11/0x20
[ 9520.404732]  ? do_raw_spin_unlock+0xa8/0x140
[ 9520.405026]  btrfs_write_dirty_block_groups+0x2af/0x6e0 [btrfs]
[ 9520.405375]  ? btrfs_start_dirty_block_groups+0x870/0x870 [btrfs]
[ 9520.405694]  ? do_raw_spin_unlock+0xa8/0x140
[ 9520.405958]  ? _raw_spin_unlock+0x27/0x40
[ 9520.406243]  ? btrfs_run_delayed_refs+0x1b8/0x230 [btrfs]
[ 9520.406574]  commit_cowonly_roots+0x4b9/0x610 [btrfs]
[ 9520.406899]  ? commit_fs_roots+0x350/0x350 [btrfs]
[ 9520.407253]  ? btrfs_run_delayed_refs+0x1b8/0x230 [btrfs]
[ 9520.407589]  btrfs_commit_transaction+0x5e5/0x10e0 [btrfs]
[ 9520.407925]  ? btrfs_apply_pending_changes+0x90/0x90 [btrfs]
[ 9520.408262]  ? start_transaction+0x168/0x6c0 [btrfs]
[ 9520.408582]  transaction_kthread+0x21c/0x240 [btrfs]
[ 9520.408870]  kthread+0x1d2/0x1f0
[ 9520.409138]  ? btrfs_cleanup_transaction+0xb50/0xb50 [btrfs]
[ 9520.409440]  ? kthread_park+0xb0/0xb0
[ 9520.409682]  ret_from_fork+0x3a/0x50
[ 9520.410508] Dumping ftrace buffer:
[ 9520.410764]    (ftrace buffer empty)
[ 9520.411007] CR2: 0000000000000011
[ 9520.411297] ---[ end trace 01a0863445cf360a ]---
[ 9520.411568] RIP: 0010:rb_next+0x3c/0x90
[ 9520.412644] RSP: 0018:ffff8801074ff780 EFLAGS: 00010292
[ 9520.412932] RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffffffff81b5ac4c
[ 9520.413274] RDX: 0000000000000000 RSI: 0000000000000008 RDI: 0000000000000011
[ 9520.413616] RBP: ffff8801074ff7a0 R08: ffffed0021d64ccc R09: ffffed0021d64ccc
[ 9520.414007] R10: 0000000000000001 R11: ffffed0021d64ccb R12: ffff8800b91e0000
[ 9520.414349] R13: ffff8800a3ceba48 R14: ffff8800b627bf80 R15: 0000000000020000
[ 9520.416074] FS:  0000000000000000(0000) GS:ffff88010eb00000(0000) knlGS:0000000000000000
[ 9520.416536] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 9520.416848] CR2: 0000000000000011 CR3: 0000000106b52000 CR4: 00000000000006a0
[ 9520.418477] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 9520.418846] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 9520.419204] Kernel panic - not syncing: Fatal exception
[ 9520.419666] Dumping ftrace buffer:
[ 9520.419930]    (ftrace buffer empty)
[ 9520.420168] Kernel Offset: disabled
[ 9520.420406] ---[ end Kernel panic - not syncing: Fatal exception ]---

Fix this by acquiring the respective lock before iterating the rbtree.

Reported-by: Nikolay Borisov <nborisov@suse.com>
CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
frank-w referenced this pull request in frank-w/BPI-Router-Linux Nov 13, 2018
commit 9084cb6 upstream.

We were iterating a block group's free space cache rbtree without locking
first the lock that protects it (the free_space_ctl->free_space_offset
rbtree is protected by the free_space_ctl->tree_lock spinlock).

KASAN reported an use-after-free problem when iterating such a rbtree due
to a concurrent rbtree delete:

[ 9520.359168] ==================================================================
[ 9520.359656] BUG: KASAN: use-after-free in rb_next+0x13/0x90
[ 9520.359949] Read of size 8 at addr ffff8800b7ada500 by task btrfs-transacti/1721
[ 9520.360357]
[ 9520.360530] CPU: 4 PID: 1721 Comm: btrfs-transacti Tainted: G             L    4.19.0-rc8-nbor #555
[ 9520.360990] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014
[ 9520.362682] Call Trace:
[ 9520.362887]  dump_stack+0xa4/0xf5
[ 9520.363146]  print_address_description+0x78/0x280
[ 9520.363412]  kasan_report+0x263/0x390
[ 9520.363650]  ? rb_next+0x13/0x90
[ 9520.363873]  __asan_load8+0x54/0x90
[ 9520.364102]  rb_next+0x13/0x90
[ 9520.364380]  btrfs_dump_free_space+0x146/0x160 [btrfs]
[ 9520.364697]  dump_space_info+0x2cd/0x310 [btrfs]
[ 9520.364997]  btrfs_reserve_extent+0x1ee/0x1f0 [btrfs]
[ 9520.365310]  __btrfs_prealloc_file_range+0x1cc/0x620 [btrfs]
[ 9520.365646]  ? btrfs_update_time+0x180/0x180 [btrfs]
[ 9520.365923]  ? _raw_spin_unlock+0x27/0x40
[ 9520.366204]  ? btrfs_alloc_data_chunk_ondemand+0x2c0/0x5c0 [btrfs]
[ 9520.366549]  btrfs_prealloc_file_range_trans+0x23/0x30 [btrfs]
[ 9520.366880]  cache_save_setup+0x42e/0x580 [btrfs]
[ 9520.367220]  ? btrfs_check_data_free_space+0xd0/0xd0 [btrfs]
[ 9520.367518]  ? lock_downgrade+0x2f0/0x2f0
[ 9520.367799]  ? btrfs_write_dirty_block_groups+0x11f/0x6e0 [btrfs]
[ 9520.368104]  ? kasan_check_read+0x11/0x20
[ 9520.368349]  ? do_raw_spin_unlock+0xa8/0x140
[ 9520.368638]  btrfs_write_dirty_block_groups+0x2af/0x6e0 [btrfs]
[ 9520.368978]  ? btrfs_start_dirty_block_groups+0x870/0x870 [btrfs]
[ 9520.369282]  ? do_raw_spin_unlock+0xa8/0x140
[ 9520.369534]  ? _raw_spin_unlock+0x27/0x40
[ 9520.369811]  ? btrfs_run_delayed_refs+0x1b8/0x230 [btrfs]
[ 9520.370137]  commit_cowonly_roots+0x4b9/0x610 [btrfs]
[ 9520.370560]  ? commit_fs_roots+0x350/0x350 [btrfs]
[ 9520.370926]  ? btrfs_run_delayed_refs+0x1b8/0x230 [btrfs]
[ 9520.371285]  btrfs_commit_transaction+0x5e5/0x10e0 [btrfs]
[ 9520.371612]  ? btrfs_apply_pending_changes+0x90/0x90 [btrfs]
[ 9520.371943]  ? start_transaction+0x168/0x6c0 [btrfs]
[ 9520.372257]  transaction_kthread+0x21c/0x240 [btrfs]
[ 9520.372537]  kthread+0x1d2/0x1f0
[ 9520.372793]  ? btrfs_cleanup_transaction+0xb50/0xb50 [btrfs]
[ 9520.373090]  ? kthread_park+0xb0/0xb0
[ 9520.373329]  ret_from_fork+0x3a/0x50
[ 9520.373567]
[ 9520.373738] Allocated by task 1804:
[ 9520.373974]  kasan_kmalloc+0xff/0x180
[ 9520.374208]  kasan_slab_alloc+0x11/0x20
[ 9520.374447]  kmem_cache_alloc+0xfc/0x2d0
[ 9520.374731]  __btrfs_add_free_space+0x40/0x580 [btrfs]
[ 9520.375044]  unpin_extent_range+0x4f7/0x7a0 [btrfs]
[ 9520.375383]  btrfs_finish_extent_commit+0x15f/0x4d0 [btrfs]
[ 9520.375707]  btrfs_commit_transaction+0xb06/0x10e0 [btrfs]
[ 9520.376027]  btrfs_alloc_data_chunk_ondemand+0x237/0x5c0 [btrfs]
[ 9520.376365]  btrfs_check_data_free_space+0x81/0xd0 [btrfs]
[ 9520.376689]  btrfs_delalloc_reserve_space+0x25/0x80 [btrfs]
[ 9520.377018]  btrfs_direct_IO+0x42e/0x6d0 [btrfs]
[ 9520.377284]  generic_file_direct_write+0x11e/0x220
[ 9520.377587]  btrfs_file_write_iter+0x472/0xac0 [btrfs]
[ 9520.377875]  aio_write+0x25c/0x360
[ 9520.378106]  io_submit_one+0xaa0/0xdc0
[ 9520.378343]  __se_sys_io_submit+0xfa/0x2f0
[ 9520.378589]  __x64_sys_io_submit+0x43/0x50
[ 9520.378840]  do_syscall_64+0x7d/0x240
[ 9520.379081]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
[ 9520.379387]
[ 9520.379557] Freed by task 1802:
[ 9520.379782]  __kasan_slab_free+0x173/0x260
[ 9520.380028]  kasan_slab_free+0xe/0x10
[ 9520.380262]  kmem_cache_free+0xc1/0x2c0
[ 9520.380544]  btrfs_find_space_for_alloc+0x4cd/0x4e0 [btrfs]
[ 9520.380866]  find_free_extent+0xa99/0x17e0 [btrfs]
[ 9520.381166]  btrfs_reserve_extent+0xd5/0x1f0 [btrfs]
[ 9520.381474]  btrfs_get_blocks_direct+0x60b/0xbd0 [btrfs]
[ 9520.381761]  __blockdev_direct_IO+0x10ee/0x58a1
[ 9520.382059]  btrfs_direct_IO+0x25a/0x6d0 [btrfs]
[ 9520.382321]  generic_file_direct_write+0x11e/0x220
[ 9520.382623]  btrfs_file_write_iter+0x472/0xac0 [btrfs]
[ 9520.382904]  aio_write+0x25c/0x360
[ 9520.383172]  io_submit_one+0xaa0/0xdc0
[ 9520.383416]  __se_sys_io_submit+0xfa/0x2f0
[ 9520.383678]  __x64_sys_io_submit+0x43/0x50
[ 9520.383927]  do_syscall_64+0x7d/0x240
[ 9520.384165]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
[ 9520.384439]
[ 9520.384610] The buggy address belongs to the object at ffff8800b7ada500
                which belongs to the cache btrfs_free_space of size 72
[ 9520.385175] The buggy address is located 0 bytes inside of
                72-byte region [ffff8800b7ada500, ffff8800b7ada548)
[ 9520.385691] The buggy address belongs to the page:
[ 9520.385957] page:ffffea0002deb680 count:1 mapcount:0 mapping:ffff880108a1d700 index:0x0 compound_mapcount: 0
[ 9520.388030] flags: 0x8100(slab|head)
[ 9520.388281] raw: 0000000000008100 ffffea0002deb608 ffffea0002728808 ffff880108a1d700
[ 9520.388722] raw: 0000000000000000 0000000000130013 00000001ffffffff 0000000000000000
[ 9520.389169] page dumped because: kasan: bad access detected
[ 9520.389473]
[ 9520.389658] Memory state around the buggy address:
[ 9520.389943]  ffff8800b7ada400: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[ 9520.390368]  ffff8800b7ada480: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[ 9520.390796] >ffff8800b7ada500: fb fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc
[ 9520.391223]                    ^
[ 9520.391461]  ffff8800b7ada580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[ 9520.391885]  ffff8800b7ada600: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[ 9520.392313] ==================================================================
[ 9520.392772] BTRFS critical (device vdc): entry offset 2258497536, bytes 131072, bitmap no
[ 9520.393247] BUG: unable to handle kernel NULL pointer dereference at 0000000000000011
[ 9520.393705] PGD 800000010dbab067 P4D 800000010dbab067 PUD 107551067 PMD 0
[ 9520.394059] Oops: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN PTI
[ 9520.394378] CPU: 4 PID: 1721 Comm: btrfs-transacti Tainted: G    B        L    4.19.0-rc8-nbor #555
[ 9520.394858] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014
[ 9520.395350] RIP: 0010:rb_next+0x3c/0x90
[ 9520.396461] RSP: 0018:ffff8801074ff780 EFLAGS: 00010292
[ 9520.396762] RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffffffff81b5ac4c
[ 9520.397115] RDX: 0000000000000000 RSI: 0000000000000008 RDI: 0000000000000011
[ 9520.397468] RBP: ffff8801074ff7a0 R08: ffffed0021d64ccc R09: ffffed0021d64ccc
[ 9520.397821] R10: 0000000000000001 R11: ffffed0021d64ccb R12: ffff8800b91e0000
[ 9520.398188] R13: ffff8800a3ceba48 R14: ffff8800b627bf80 R15: 0000000000020000
[ 9520.398555] FS:  0000000000000000(0000) GS:ffff88010eb00000(0000) knlGS:0000000000000000
[ 9520.399007] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 9520.399335] CR2: 0000000000000011 CR3: 0000000106b52000 CR4: 00000000000006a0
[ 9520.399679] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 9520.400023] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 9520.400400] Call Trace:
[ 9520.400648]  btrfs_dump_free_space+0x146/0x160 [btrfs]
[ 9520.400974]  dump_space_info+0x2cd/0x310 [btrfs]
[ 9520.401287]  btrfs_reserve_extent+0x1ee/0x1f0 [btrfs]
[ 9520.401609]  __btrfs_prealloc_file_range+0x1cc/0x620 [btrfs]
[ 9520.401952]  ? btrfs_update_time+0x180/0x180 [btrfs]
[ 9520.402232]  ? _raw_spin_unlock+0x27/0x40
[ 9520.402522]  ? btrfs_alloc_data_chunk_ondemand+0x2c0/0x5c0 [btrfs]
[ 9520.402882]  btrfs_prealloc_file_range_trans+0x23/0x30 [btrfs]
[ 9520.403261]  cache_save_setup+0x42e/0x580 [btrfs]
[ 9520.403570]  ? btrfs_check_data_free_space+0xd0/0xd0 [btrfs]
[ 9520.403871]  ? lock_downgrade+0x2f0/0x2f0
[ 9520.404161]  ? btrfs_write_dirty_block_groups+0x11f/0x6e0 [btrfs]
[ 9520.404481]  ? kasan_check_read+0x11/0x20
[ 9520.404732]  ? do_raw_spin_unlock+0xa8/0x140
[ 9520.405026]  btrfs_write_dirty_block_groups+0x2af/0x6e0 [btrfs]
[ 9520.405375]  ? btrfs_start_dirty_block_groups+0x870/0x870 [btrfs]
[ 9520.405694]  ? do_raw_spin_unlock+0xa8/0x140
[ 9520.405958]  ? _raw_spin_unlock+0x27/0x40
[ 9520.406243]  ? btrfs_run_delayed_refs+0x1b8/0x230 [btrfs]
[ 9520.406574]  commit_cowonly_roots+0x4b9/0x610 [btrfs]
[ 9520.406899]  ? commit_fs_roots+0x350/0x350 [btrfs]
[ 9520.407253]  ? btrfs_run_delayed_refs+0x1b8/0x230 [btrfs]
[ 9520.407589]  btrfs_commit_transaction+0x5e5/0x10e0 [btrfs]
[ 9520.407925]  ? btrfs_apply_pending_changes+0x90/0x90 [btrfs]
[ 9520.408262]  ? start_transaction+0x168/0x6c0 [btrfs]
[ 9520.408582]  transaction_kthread+0x21c/0x240 [btrfs]
[ 9520.408870]  kthread+0x1d2/0x1f0
[ 9520.409138]  ? btrfs_cleanup_transaction+0xb50/0xb50 [btrfs]
[ 9520.409440]  ? kthread_park+0xb0/0xb0
[ 9520.409682]  ret_from_fork+0x3a/0x50
[ 9520.410508] Dumping ftrace buffer:
[ 9520.410764]    (ftrace buffer empty)
[ 9520.411007] CR2: 0000000000000011
[ 9520.411297] ---[ end trace 01a0863445cf360a ]---
[ 9520.411568] RIP: 0010:rb_next+0x3c/0x90
[ 9520.412644] RSP: 0018:ffff8801074ff780 EFLAGS: 00010292
[ 9520.412932] RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffffffff81b5ac4c
[ 9520.413274] RDX: 0000000000000000 RSI: 0000000000000008 RDI: 0000000000000011
[ 9520.413616] RBP: ffff8801074ff7a0 R08: ffffed0021d64ccc R09: ffffed0021d64ccc
[ 9520.414007] R10: 0000000000000001 R11: ffffed0021d64ccb R12: ffff8800b91e0000
[ 9520.414349] R13: ffff8800a3ceba48 R14: ffff8800b627bf80 R15: 0000000000020000
[ 9520.416074] FS:  0000000000000000(0000) GS:ffff88010eb00000(0000) knlGS:0000000000000000
[ 9520.416536] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 9520.416848] CR2: 0000000000000011 CR3: 0000000106b52000 CR4: 00000000000006a0
[ 9520.418477] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 9520.418846] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 9520.419204] Kernel panic - not syncing: Fatal exception
[ 9520.419666] Dumping ftrace buffer:
[ 9520.419930]    (ftrace buffer empty)
[ 9520.420168] Kernel Offset: disabled
[ 9520.420406] ---[ end Kernel panic - not syncing: Fatal exception ]---

Fix this by acquiring the respective lock before iterating the rbtree.

Reported-by: Nikolay Borisov <nborisov@suse.com>
CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
frank-w referenced this pull request in frank-w/BPI-Router-Linux Nov 13, 2018
commit 9084cb6 upstream.

We were iterating a block group's free space cache rbtree without locking
first the lock that protects it (the free_space_ctl->free_space_offset
rbtree is protected by the free_space_ctl->tree_lock spinlock).

KASAN reported an use-after-free problem when iterating such a rbtree due
to a concurrent rbtree delete:

[ 9520.359168] ==================================================================
[ 9520.359656] BUG: KASAN: use-after-free in rb_next+0x13/0x90
[ 9520.359949] Read of size 8 at addr ffff8800b7ada500 by task btrfs-transacti/1721
[ 9520.360357]
[ 9520.360530] CPU: 4 PID: 1721 Comm: btrfs-transacti Tainted: G             L    4.19.0-rc8-nbor #555
[ 9520.360990] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014
[ 9520.362682] Call Trace:
[ 9520.362887]  dump_stack+0xa4/0xf5
[ 9520.363146]  print_address_description+0x78/0x280
[ 9520.363412]  kasan_report+0x263/0x390
[ 9520.363650]  ? rb_next+0x13/0x90
[ 9520.363873]  __asan_load8+0x54/0x90
[ 9520.364102]  rb_next+0x13/0x90
[ 9520.364380]  btrfs_dump_free_space+0x146/0x160 [btrfs]
[ 9520.364697]  dump_space_info+0x2cd/0x310 [btrfs]
[ 9520.364997]  btrfs_reserve_extent+0x1ee/0x1f0 [btrfs]
[ 9520.365310]  __btrfs_prealloc_file_range+0x1cc/0x620 [btrfs]
[ 9520.365646]  ? btrfs_update_time+0x180/0x180 [btrfs]
[ 9520.365923]  ? _raw_spin_unlock+0x27/0x40
[ 9520.366204]  ? btrfs_alloc_data_chunk_ondemand+0x2c0/0x5c0 [btrfs]
[ 9520.366549]  btrfs_prealloc_file_range_trans+0x23/0x30 [btrfs]
[ 9520.366880]  cache_save_setup+0x42e/0x580 [btrfs]
[ 9520.367220]  ? btrfs_check_data_free_space+0xd0/0xd0 [btrfs]
[ 9520.367518]  ? lock_downgrade+0x2f0/0x2f0
[ 9520.367799]  ? btrfs_write_dirty_block_groups+0x11f/0x6e0 [btrfs]
[ 9520.368104]  ? kasan_check_read+0x11/0x20
[ 9520.368349]  ? do_raw_spin_unlock+0xa8/0x140
[ 9520.368638]  btrfs_write_dirty_block_groups+0x2af/0x6e0 [btrfs]
[ 9520.368978]  ? btrfs_start_dirty_block_groups+0x870/0x870 [btrfs]
[ 9520.369282]  ? do_raw_spin_unlock+0xa8/0x140
[ 9520.369534]  ? _raw_spin_unlock+0x27/0x40
[ 9520.369811]  ? btrfs_run_delayed_refs+0x1b8/0x230 [btrfs]
[ 9520.370137]  commit_cowonly_roots+0x4b9/0x610 [btrfs]
[ 9520.370560]  ? commit_fs_roots+0x350/0x350 [btrfs]
[ 9520.370926]  ? btrfs_run_delayed_refs+0x1b8/0x230 [btrfs]
[ 9520.371285]  btrfs_commit_transaction+0x5e5/0x10e0 [btrfs]
[ 9520.371612]  ? btrfs_apply_pending_changes+0x90/0x90 [btrfs]
[ 9520.371943]  ? start_transaction+0x168/0x6c0 [btrfs]
[ 9520.372257]  transaction_kthread+0x21c/0x240 [btrfs]
[ 9520.372537]  kthread+0x1d2/0x1f0
[ 9520.372793]  ? btrfs_cleanup_transaction+0xb50/0xb50 [btrfs]
[ 9520.373090]  ? kthread_park+0xb0/0xb0
[ 9520.373329]  ret_from_fork+0x3a/0x50
[ 9520.373567]
[ 9520.373738] Allocated by task 1804:
[ 9520.373974]  kasan_kmalloc+0xff/0x180
[ 9520.374208]  kasan_slab_alloc+0x11/0x20
[ 9520.374447]  kmem_cache_alloc+0xfc/0x2d0
[ 9520.374731]  __btrfs_add_free_space+0x40/0x580 [btrfs]
[ 9520.375044]  unpin_extent_range+0x4f7/0x7a0 [btrfs]
[ 9520.375383]  btrfs_finish_extent_commit+0x15f/0x4d0 [btrfs]
[ 9520.375707]  btrfs_commit_transaction+0xb06/0x10e0 [btrfs]
[ 9520.376027]  btrfs_alloc_data_chunk_ondemand+0x237/0x5c0 [btrfs]
[ 9520.376365]  btrfs_check_data_free_space+0x81/0xd0 [btrfs]
[ 9520.376689]  btrfs_delalloc_reserve_space+0x25/0x80 [btrfs]
[ 9520.377018]  btrfs_direct_IO+0x42e/0x6d0 [btrfs]
[ 9520.377284]  generic_file_direct_write+0x11e/0x220
[ 9520.377587]  btrfs_file_write_iter+0x472/0xac0 [btrfs]
[ 9520.377875]  aio_write+0x25c/0x360
[ 9520.378106]  io_submit_one+0xaa0/0xdc0
[ 9520.378343]  __se_sys_io_submit+0xfa/0x2f0
[ 9520.378589]  __x64_sys_io_submit+0x43/0x50
[ 9520.378840]  do_syscall_64+0x7d/0x240
[ 9520.379081]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
[ 9520.379387]
[ 9520.379557] Freed by task 1802:
[ 9520.379782]  __kasan_slab_free+0x173/0x260
[ 9520.380028]  kasan_slab_free+0xe/0x10
[ 9520.380262]  kmem_cache_free+0xc1/0x2c0
[ 9520.380544]  btrfs_find_space_for_alloc+0x4cd/0x4e0 [btrfs]
[ 9520.380866]  find_free_extent+0xa99/0x17e0 [btrfs]
[ 9520.381166]  btrfs_reserve_extent+0xd5/0x1f0 [btrfs]
[ 9520.381474]  btrfs_get_blocks_direct+0x60b/0xbd0 [btrfs]
[ 9520.381761]  __blockdev_direct_IO+0x10ee/0x58a1
[ 9520.382059]  btrfs_direct_IO+0x25a/0x6d0 [btrfs]
[ 9520.382321]  generic_file_direct_write+0x11e/0x220
[ 9520.382623]  btrfs_file_write_iter+0x472/0xac0 [btrfs]
[ 9520.382904]  aio_write+0x25c/0x360
[ 9520.383172]  io_submit_one+0xaa0/0xdc0
[ 9520.383416]  __se_sys_io_submit+0xfa/0x2f0
[ 9520.383678]  __x64_sys_io_submit+0x43/0x50
[ 9520.383927]  do_syscall_64+0x7d/0x240
[ 9520.384165]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
[ 9520.384439]
[ 9520.384610] The buggy address belongs to the object at ffff8800b7ada500
                which belongs to the cache btrfs_free_space of size 72
[ 9520.385175] The buggy address is located 0 bytes inside of
                72-byte region [ffff8800b7ada500, ffff8800b7ada548)
[ 9520.385691] The buggy address belongs to the page:
[ 9520.385957] page:ffffea0002deb680 count:1 mapcount:0 mapping:ffff880108a1d700 index:0x0 compound_mapcount: 0
[ 9520.388030] flags: 0x8100(slab|head)
[ 9520.388281] raw: 0000000000008100 ffffea0002deb608 ffffea0002728808 ffff880108a1d700
[ 9520.388722] raw: 0000000000000000 0000000000130013 00000001ffffffff 0000000000000000
[ 9520.389169] page dumped because: kasan: bad access detected
[ 9520.389473]
[ 9520.389658] Memory state around the buggy address:
[ 9520.389943]  ffff8800b7ada400: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[ 9520.390368]  ffff8800b7ada480: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[ 9520.390796] >ffff8800b7ada500: fb fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc
[ 9520.391223]                    ^
[ 9520.391461]  ffff8800b7ada580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[ 9520.391885]  ffff8800b7ada600: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[ 9520.392313] ==================================================================
[ 9520.392772] BTRFS critical (device vdc): entry offset 2258497536, bytes 131072, bitmap no
[ 9520.393247] BUG: unable to handle kernel NULL pointer dereference at 0000000000000011
[ 9520.393705] PGD 800000010dbab067 P4D 800000010dbab067 PUD 107551067 PMD 0
[ 9520.394059] Oops: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN PTI
[ 9520.394378] CPU: 4 PID: 1721 Comm: btrfs-transacti Tainted: G    B        L    4.19.0-rc8-nbor #555
[ 9520.394858] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014
[ 9520.395350] RIP: 0010:rb_next+0x3c/0x90
[ 9520.396461] RSP: 0018:ffff8801074ff780 EFLAGS: 00010292
[ 9520.396762] RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffffffff81b5ac4c
[ 9520.397115] RDX: 0000000000000000 RSI: 0000000000000008 RDI: 0000000000000011
[ 9520.397468] RBP: ffff8801074ff7a0 R08: ffffed0021d64ccc R09: ffffed0021d64ccc
[ 9520.397821] R10: 0000000000000001 R11: ffffed0021d64ccb R12: ffff8800b91e0000
[ 9520.398188] R13: ffff8800a3ceba48 R14: ffff8800b627bf80 R15: 0000000000020000
[ 9520.398555] FS:  0000000000000000(0000) GS:ffff88010eb00000(0000) knlGS:0000000000000000
[ 9520.399007] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 9520.399335] CR2: 0000000000000011 CR3: 0000000106b52000 CR4: 00000000000006a0
[ 9520.399679] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 9520.400023] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 9520.400400] Call Trace:
[ 9520.400648]  btrfs_dump_free_space+0x146/0x160 [btrfs]
[ 9520.400974]  dump_space_info+0x2cd/0x310 [btrfs]
[ 9520.401287]  btrfs_reserve_extent+0x1ee/0x1f0 [btrfs]
[ 9520.401609]  __btrfs_prealloc_file_range+0x1cc/0x620 [btrfs]
[ 9520.401952]  ? btrfs_update_time+0x180/0x180 [btrfs]
[ 9520.402232]  ? _raw_spin_unlock+0x27/0x40
[ 9520.402522]  ? btrfs_alloc_data_chunk_ondemand+0x2c0/0x5c0 [btrfs]
[ 9520.402882]  btrfs_prealloc_file_range_trans+0x23/0x30 [btrfs]
[ 9520.403261]  cache_save_setup+0x42e/0x580 [btrfs]
[ 9520.403570]  ? btrfs_check_data_free_space+0xd0/0xd0 [btrfs]
[ 9520.403871]  ? lock_downgrade+0x2f0/0x2f0
[ 9520.404161]  ? btrfs_write_dirty_block_groups+0x11f/0x6e0 [btrfs]
[ 9520.404481]  ? kasan_check_read+0x11/0x20
[ 9520.404732]  ? do_raw_spin_unlock+0xa8/0x140
[ 9520.405026]  btrfs_write_dirty_block_groups+0x2af/0x6e0 [btrfs]
[ 9520.405375]  ? btrfs_start_dirty_block_groups+0x870/0x870 [btrfs]
[ 9520.405694]  ? do_raw_spin_unlock+0xa8/0x140
[ 9520.405958]  ? _raw_spin_unlock+0x27/0x40
[ 9520.406243]  ? btrfs_run_delayed_refs+0x1b8/0x230 [btrfs]
[ 9520.406574]  commit_cowonly_roots+0x4b9/0x610 [btrfs]
[ 9520.406899]  ? commit_fs_roots+0x350/0x350 [btrfs]
[ 9520.407253]  ? btrfs_run_delayed_refs+0x1b8/0x230 [btrfs]
[ 9520.407589]  btrfs_commit_transaction+0x5e5/0x10e0 [btrfs]
[ 9520.407925]  ? btrfs_apply_pending_changes+0x90/0x90 [btrfs]
[ 9520.408262]  ? start_transaction+0x168/0x6c0 [btrfs]
[ 9520.408582]  transaction_kthread+0x21c/0x240 [btrfs]
[ 9520.408870]  kthread+0x1d2/0x1f0
[ 9520.409138]  ? btrfs_cleanup_transaction+0xb50/0xb50 [btrfs]
[ 9520.409440]  ? kthread_park+0xb0/0xb0
[ 9520.409682]  ret_from_fork+0x3a/0x50
[ 9520.410508] Dumping ftrace buffer:
[ 9520.410764]    (ftrace buffer empty)
[ 9520.411007] CR2: 0000000000000011
[ 9520.411297] ---[ end trace 01a0863445cf360a ]---
[ 9520.411568] RIP: 0010:rb_next+0x3c/0x90
[ 9520.412644] RSP: 0018:ffff8801074ff780 EFLAGS: 00010292
[ 9520.412932] RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffffffff81b5ac4c
[ 9520.413274] RDX: 0000000000000000 RSI: 0000000000000008 RDI: 0000000000000011
[ 9520.413616] RBP: ffff8801074ff7a0 R08: ffffed0021d64ccc R09: ffffed0021d64ccc
[ 9520.414007] R10: 0000000000000001 R11: ffffed0021d64ccb R12: ffff8800b91e0000
[ 9520.414349] R13: ffff8800a3ceba48 R14: ffff8800b627bf80 R15: 0000000000020000
[ 9520.416074] FS:  0000000000000000(0000) GS:ffff88010eb00000(0000) knlGS:0000000000000000
[ 9520.416536] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 9520.416848] CR2: 0000000000000011 CR3: 0000000106b52000 CR4: 00000000000006a0
[ 9520.418477] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 9520.418846] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 9520.419204] Kernel panic - not syncing: Fatal exception
[ 9520.419666] Dumping ftrace buffer:
[ 9520.419930]    (ftrace buffer empty)
[ 9520.420168] Kernel Offset: disabled
[ 9520.420406] ---[ end Kernel panic - not syncing: Fatal exception ]---

Fix this by acquiring the respective lock before iterating the rbtree.

Reported-by: Nikolay Borisov <nborisov@suse.com>
CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Noltari pushed a commit to Noltari/linux that referenced this pull request Dec 8, 2018
commit 9084cb6 upstream.

We were iterating a block group's free space cache rbtree without locking
first the lock that protects it (the free_space_ctl->free_space_offset
rbtree is protected by the free_space_ctl->tree_lock spinlock).

KASAN reported an use-after-free problem when iterating such a rbtree due
to a concurrent rbtree delete:

[ 9520.359168] ==================================================================
[ 9520.359656] BUG: KASAN: use-after-free in rb_next+0x13/0x90
[ 9520.359949] Read of size 8 at addr ffff8800b7ada500 by task btrfs-transacti/1721
[ 9520.360357]
[ 9520.360530] CPU: 4 PID: 1721 Comm: btrfs-transacti Tainted: G             L    4.19.0-rc8-nbor torvalds#555
[ 9520.360990] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014
[ 9520.362682] Call Trace:
[ 9520.362887]  dump_stack+0xa4/0xf5
[ 9520.363146]  print_address_description+0x78/0x280
[ 9520.363412]  kasan_report+0x263/0x390
[ 9520.363650]  ? rb_next+0x13/0x90
[ 9520.363873]  __asan_load8+0x54/0x90
[ 9520.364102]  rb_next+0x13/0x90
[ 9520.364380]  btrfs_dump_free_space+0x146/0x160 [btrfs]
[ 9520.364697]  dump_space_info+0x2cd/0x310 [btrfs]
[ 9520.364997]  btrfs_reserve_extent+0x1ee/0x1f0 [btrfs]
[ 9520.365310]  __btrfs_prealloc_file_range+0x1cc/0x620 [btrfs]
[ 9520.365646]  ? btrfs_update_time+0x180/0x180 [btrfs]
[ 9520.365923]  ? _raw_spin_unlock+0x27/0x40
[ 9520.366204]  ? btrfs_alloc_data_chunk_ondemand+0x2c0/0x5c0 [btrfs]
[ 9520.366549]  btrfs_prealloc_file_range_trans+0x23/0x30 [btrfs]
[ 9520.366880]  cache_save_setup+0x42e/0x580 [btrfs]
[ 9520.367220]  ? btrfs_check_data_free_space+0xd0/0xd0 [btrfs]
[ 9520.367518]  ? lock_downgrade+0x2f0/0x2f0
[ 9520.367799]  ? btrfs_write_dirty_block_groups+0x11f/0x6e0 [btrfs]
[ 9520.368104]  ? kasan_check_read+0x11/0x20
[ 9520.368349]  ? do_raw_spin_unlock+0xa8/0x140
[ 9520.368638]  btrfs_write_dirty_block_groups+0x2af/0x6e0 [btrfs]
[ 9520.368978]  ? btrfs_start_dirty_block_groups+0x870/0x870 [btrfs]
[ 9520.369282]  ? do_raw_spin_unlock+0xa8/0x140
[ 9520.369534]  ? _raw_spin_unlock+0x27/0x40
[ 9520.369811]  ? btrfs_run_delayed_refs+0x1b8/0x230 [btrfs]
[ 9520.370137]  commit_cowonly_roots+0x4b9/0x610 [btrfs]
[ 9520.370560]  ? commit_fs_roots+0x350/0x350 [btrfs]
[ 9520.370926]  ? btrfs_run_delayed_refs+0x1b8/0x230 [btrfs]
[ 9520.371285]  btrfs_commit_transaction+0x5e5/0x10e0 [btrfs]
[ 9520.371612]  ? btrfs_apply_pending_changes+0x90/0x90 [btrfs]
[ 9520.371943]  ? start_transaction+0x168/0x6c0 [btrfs]
[ 9520.372257]  transaction_kthread+0x21c/0x240 [btrfs]
[ 9520.372537]  kthread+0x1d2/0x1f0
[ 9520.372793]  ? btrfs_cleanup_transaction+0xb50/0xb50 [btrfs]
[ 9520.373090]  ? kthread_park+0xb0/0xb0
[ 9520.373329]  ret_from_fork+0x3a/0x50
[ 9520.373567]
[ 9520.373738] Allocated by task 1804:
[ 9520.373974]  kasan_kmalloc+0xff/0x180
[ 9520.374208]  kasan_slab_alloc+0x11/0x20
[ 9520.374447]  kmem_cache_alloc+0xfc/0x2d0
[ 9520.374731]  __btrfs_add_free_space+0x40/0x580 [btrfs]
[ 9520.375044]  unpin_extent_range+0x4f7/0x7a0 [btrfs]
[ 9520.375383]  btrfs_finish_extent_commit+0x15f/0x4d0 [btrfs]
[ 9520.375707]  btrfs_commit_transaction+0xb06/0x10e0 [btrfs]
[ 9520.376027]  btrfs_alloc_data_chunk_ondemand+0x237/0x5c0 [btrfs]
[ 9520.376365]  btrfs_check_data_free_space+0x81/0xd0 [btrfs]
[ 9520.376689]  btrfs_delalloc_reserve_space+0x25/0x80 [btrfs]
[ 9520.377018]  btrfs_direct_IO+0x42e/0x6d0 [btrfs]
[ 9520.377284]  generic_file_direct_write+0x11e/0x220
[ 9520.377587]  btrfs_file_write_iter+0x472/0xac0 [btrfs]
[ 9520.377875]  aio_write+0x25c/0x360
[ 9520.378106]  io_submit_one+0xaa0/0xdc0
[ 9520.378343]  __se_sys_io_submit+0xfa/0x2f0
[ 9520.378589]  __x64_sys_io_submit+0x43/0x50
[ 9520.378840]  do_syscall_64+0x7d/0x240
[ 9520.379081]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
[ 9520.379387]
[ 9520.379557] Freed by task 1802:
[ 9520.379782]  __kasan_slab_free+0x173/0x260
[ 9520.380028]  kasan_slab_free+0xe/0x10
[ 9520.380262]  kmem_cache_free+0xc1/0x2c0
[ 9520.380544]  btrfs_find_space_for_alloc+0x4cd/0x4e0 [btrfs]
[ 9520.380866]  find_free_extent+0xa99/0x17e0 [btrfs]
[ 9520.381166]  btrfs_reserve_extent+0xd5/0x1f0 [btrfs]
[ 9520.381474]  btrfs_get_blocks_direct+0x60b/0xbd0 [btrfs]
[ 9520.381761]  __blockdev_direct_IO+0x10ee/0x58a1
[ 9520.382059]  btrfs_direct_IO+0x25a/0x6d0 [btrfs]
[ 9520.382321]  generic_file_direct_write+0x11e/0x220
[ 9520.382623]  btrfs_file_write_iter+0x472/0xac0 [btrfs]
[ 9520.382904]  aio_write+0x25c/0x360
[ 9520.383172]  io_submit_one+0xaa0/0xdc0
[ 9520.383416]  __se_sys_io_submit+0xfa/0x2f0
[ 9520.383678]  __x64_sys_io_submit+0x43/0x50
[ 9520.383927]  do_syscall_64+0x7d/0x240
[ 9520.384165]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
[ 9520.384439]
[ 9520.384610] The buggy address belongs to the object at ffff8800b7ada500
                which belongs to the cache btrfs_free_space of size 72
[ 9520.385175] The buggy address is located 0 bytes inside of
                72-byte region [ffff8800b7ada500, ffff8800b7ada548)
[ 9520.385691] The buggy address belongs to the page:
[ 9520.385957] page:ffffea0002deb680 count:1 mapcount:0 mapping:ffff880108a1d700 index:0x0 compound_mapcount: 0
[ 9520.388030] flags: 0x8100(slab|head)
[ 9520.388281] raw: 0000000000008100 ffffea0002deb608 ffffea0002728808 ffff880108a1d700
[ 9520.388722] raw: 0000000000000000 0000000000130013 00000001ffffffff 0000000000000000
[ 9520.389169] page dumped because: kasan: bad access detected
[ 9520.389473]
[ 9520.389658] Memory state around the buggy address:
[ 9520.389943]  ffff8800b7ada400: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[ 9520.390368]  ffff8800b7ada480: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[ 9520.390796] >ffff8800b7ada500: fb fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc
[ 9520.391223]                    ^
[ 9520.391461]  ffff8800b7ada580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[ 9520.391885]  ffff8800b7ada600: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[ 9520.392313] ==================================================================
[ 9520.392772] BTRFS critical (device vdc): entry offset 2258497536, bytes 131072, bitmap no
[ 9520.393247] BUG: unable to handle kernel NULL pointer dereference at 0000000000000011
[ 9520.393705] PGD 800000010dbab067 P4D 800000010dbab067 PUD 107551067 PMD 0
[ 9520.394059] Oops: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN PTI
[ 9520.394378] CPU: 4 PID: 1721 Comm: btrfs-transacti Tainted: G    B        L    4.19.0-rc8-nbor torvalds#555
[ 9520.394858] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014
[ 9520.395350] RIP: 0010:rb_next+0x3c/0x90
[ 9520.396461] RSP: 0018:ffff8801074ff780 EFLAGS: 00010292
[ 9520.396762] RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffffffff81b5ac4c
[ 9520.397115] RDX: 0000000000000000 RSI: 0000000000000008 RDI: 0000000000000011
[ 9520.397468] RBP: ffff8801074ff7a0 R08: ffffed0021d64ccc R09: ffffed0021d64ccc
[ 9520.397821] R10: 0000000000000001 R11: ffffed0021d64ccb R12: ffff8800b91e0000
[ 9520.398188] R13: ffff8800a3ceba48 R14: ffff8800b627bf80 R15: 0000000000020000
[ 9520.398555] FS:  0000000000000000(0000) GS:ffff88010eb00000(0000) knlGS:0000000000000000
[ 9520.399007] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 9520.399335] CR2: 0000000000000011 CR3: 0000000106b52000 CR4: 00000000000006a0
[ 9520.399679] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 9520.400023] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 9520.400400] Call Trace:
[ 9520.400648]  btrfs_dump_free_space+0x146/0x160 [btrfs]
[ 9520.400974]  dump_space_info+0x2cd/0x310 [btrfs]
[ 9520.401287]  btrfs_reserve_extent+0x1ee/0x1f0 [btrfs]
[ 9520.401609]  __btrfs_prealloc_file_range+0x1cc/0x620 [btrfs]
[ 9520.401952]  ? btrfs_update_time+0x180/0x180 [btrfs]
[ 9520.402232]  ? _raw_spin_unlock+0x27/0x40
[ 9520.402522]  ? btrfs_alloc_data_chunk_ondemand+0x2c0/0x5c0 [btrfs]
[ 9520.402882]  btrfs_prealloc_file_range_trans+0x23/0x30 [btrfs]
[ 9520.403261]  cache_save_setup+0x42e/0x580 [btrfs]
[ 9520.403570]  ? btrfs_check_data_free_space+0xd0/0xd0 [btrfs]
[ 9520.403871]  ? lock_downgrade+0x2f0/0x2f0
[ 9520.404161]  ? btrfs_write_dirty_block_groups+0x11f/0x6e0 [btrfs]
[ 9520.404481]  ? kasan_check_read+0x11/0x20
[ 9520.404732]  ? do_raw_spin_unlock+0xa8/0x140
[ 9520.405026]  btrfs_write_dirty_block_groups+0x2af/0x6e0 [btrfs]
[ 9520.405375]  ? btrfs_start_dirty_block_groups+0x870/0x870 [btrfs]
[ 9520.405694]  ? do_raw_spin_unlock+0xa8/0x140
[ 9520.405958]  ? _raw_spin_unlock+0x27/0x40
[ 9520.406243]  ? btrfs_run_delayed_refs+0x1b8/0x230 [btrfs]
[ 9520.406574]  commit_cowonly_roots+0x4b9/0x610 [btrfs]
[ 9520.406899]  ? commit_fs_roots+0x350/0x350 [btrfs]
[ 9520.407253]  ? btrfs_run_delayed_refs+0x1b8/0x230 [btrfs]
[ 9520.407589]  btrfs_commit_transaction+0x5e5/0x10e0 [btrfs]
[ 9520.407925]  ? btrfs_apply_pending_changes+0x90/0x90 [btrfs]
[ 9520.408262]  ? start_transaction+0x168/0x6c0 [btrfs]
[ 9520.408582]  transaction_kthread+0x21c/0x240 [btrfs]
[ 9520.408870]  kthread+0x1d2/0x1f0
[ 9520.409138]  ? btrfs_cleanup_transaction+0xb50/0xb50 [btrfs]
[ 9520.409440]  ? kthread_park+0xb0/0xb0
[ 9520.409682]  ret_from_fork+0x3a/0x50
[ 9520.410508] Dumping ftrace buffer:
[ 9520.410764]    (ftrace buffer empty)
[ 9520.411007] CR2: 0000000000000011
[ 9520.411297] ---[ end trace 01a0863445cf360a ]---
[ 9520.411568] RIP: 0010:rb_next+0x3c/0x90
[ 9520.412644] RSP: 0018:ffff8801074ff780 EFLAGS: 00010292
[ 9520.412932] RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffffffff81b5ac4c
[ 9520.413274] RDX: 0000000000000000 RSI: 0000000000000008 RDI: 0000000000000011
[ 9520.413616] RBP: ffff8801074ff7a0 R08: ffffed0021d64ccc R09: ffffed0021d64ccc
[ 9520.414007] R10: 0000000000000001 R11: ffffed0021d64ccb R12: ffff8800b91e0000
[ 9520.414349] R13: ffff8800a3ceba48 R14: ffff8800b627bf80 R15: 0000000000020000
[ 9520.416074] FS:  0000000000000000(0000) GS:ffff88010eb00000(0000) knlGS:0000000000000000
[ 9520.416536] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 9520.416848] CR2: 0000000000000011 CR3: 0000000106b52000 CR4: 00000000000006a0
[ 9520.418477] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 9520.418846] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 9520.419204] Kernel panic - not syncing: Fatal exception
[ 9520.419666] Dumping ftrace buffer:
[ 9520.419930]    (ftrace buffer empty)
[ 9520.420168] Kernel Offset: disabled
[ 9520.420406] ---[ end Kernel panic - not syncing: Fatal exception ]---

Fix this by acquiring the respective lock before iterating the rbtree.

Reported-by: Nikolay Borisov <nborisov@suse.com>
CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Cc: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Noltari pushed a commit to Noltari/linux that referenced this pull request Dec 13, 2018
commit 9084cb6 upstream.

We were iterating a block group's free space cache rbtree without locking
first the lock that protects it (the free_space_ctl->free_space_offset
rbtree is protected by the free_space_ctl->tree_lock spinlock).

KASAN reported an use-after-free problem when iterating such a rbtree due
to a concurrent rbtree delete:

[ 9520.359168] ==================================================================
[ 9520.359656] BUG: KASAN: use-after-free in rb_next+0x13/0x90
[ 9520.359949] Read of size 8 at addr ffff8800b7ada500 by task btrfs-transacti/1721
[ 9520.360357]
[ 9520.360530] CPU: 4 PID: 1721 Comm: btrfs-transacti Tainted: G             L    4.19.0-rc8-nbor torvalds#555
[ 9520.360990] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014
[ 9520.362682] Call Trace:
[ 9520.362887]  dump_stack+0xa4/0xf5
[ 9520.363146]  print_address_description+0x78/0x280
[ 9520.363412]  kasan_report+0x263/0x390
[ 9520.363650]  ? rb_next+0x13/0x90
[ 9520.363873]  __asan_load8+0x54/0x90
[ 9520.364102]  rb_next+0x13/0x90
[ 9520.364380]  btrfs_dump_free_space+0x146/0x160 [btrfs]
[ 9520.364697]  dump_space_info+0x2cd/0x310 [btrfs]
[ 9520.364997]  btrfs_reserve_extent+0x1ee/0x1f0 [btrfs]
[ 9520.365310]  __btrfs_prealloc_file_range+0x1cc/0x620 [btrfs]
[ 9520.365646]  ? btrfs_update_time+0x180/0x180 [btrfs]
[ 9520.365923]  ? _raw_spin_unlock+0x27/0x40
[ 9520.366204]  ? btrfs_alloc_data_chunk_ondemand+0x2c0/0x5c0 [btrfs]
[ 9520.366549]  btrfs_prealloc_file_range_trans+0x23/0x30 [btrfs]
[ 9520.366880]  cache_save_setup+0x42e/0x580 [btrfs]
[ 9520.367220]  ? btrfs_check_data_free_space+0xd0/0xd0 [btrfs]
[ 9520.367518]  ? lock_downgrade+0x2f0/0x2f0
[ 9520.367799]  ? btrfs_write_dirty_block_groups+0x11f/0x6e0 [btrfs]
[ 9520.368104]  ? kasan_check_read+0x11/0x20
[ 9520.368349]  ? do_raw_spin_unlock+0xa8/0x140
[ 9520.368638]  btrfs_write_dirty_block_groups+0x2af/0x6e0 [btrfs]
[ 9520.368978]  ? btrfs_start_dirty_block_groups+0x870/0x870 [btrfs]
[ 9520.369282]  ? do_raw_spin_unlock+0xa8/0x140
[ 9520.369534]  ? _raw_spin_unlock+0x27/0x40
[ 9520.369811]  ? btrfs_run_delayed_refs+0x1b8/0x230 [btrfs]
[ 9520.370137]  commit_cowonly_roots+0x4b9/0x610 [btrfs]
[ 9520.370560]  ? commit_fs_roots+0x350/0x350 [btrfs]
[ 9520.370926]  ? btrfs_run_delayed_refs+0x1b8/0x230 [btrfs]
[ 9520.371285]  btrfs_commit_transaction+0x5e5/0x10e0 [btrfs]
[ 9520.371612]  ? btrfs_apply_pending_changes+0x90/0x90 [btrfs]
[ 9520.371943]  ? start_transaction+0x168/0x6c0 [btrfs]
[ 9520.372257]  transaction_kthread+0x21c/0x240 [btrfs]
[ 9520.372537]  kthread+0x1d2/0x1f0
[ 9520.372793]  ? btrfs_cleanup_transaction+0xb50/0xb50 [btrfs]
[ 9520.373090]  ? kthread_park+0xb0/0xb0
[ 9520.373329]  ret_from_fork+0x3a/0x50
[ 9520.373567]
[ 9520.373738] Allocated by task 1804:
[ 9520.373974]  kasan_kmalloc+0xff/0x180
[ 9520.374208]  kasan_slab_alloc+0x11/0x20
[ 9520.374447]  kmem_cache_alloc+0xfc/0x2d0
[ 9520.374731]  __btrfs_add_free_space+0x40/0x580 [btrfs]
[ 9520.375044]  unpin_extent_range+0x4f7/0x7a0 [btrfs]
[ 9520.375383]  btrfs_finish_extent_commit+0x15f/0x4d0 [btrfs]
[ 9520.375707]  btrfs_commit_transaction+0xb06/0x10e0 [btrfs]
[ 9520.376027]  btrfs_alloc_data_chunk_ondemand+0x237/0x5c0 [btrfs]
[ 9520.376365]  btrfs_check_data_free_space+0x81/0xd0 [btrfs]
[ 9520.376689]  btrfs_delalloc_reserve_space+0x25/0x80 [btrfs]
[ 9520.377018]  btrfs_direct_IO+0x42e/0x6d0 [btrfs]
[ 9520.377284]  generic_file_direct_write+0x11e/0x220
[ 9520.377587]  btrfs_file_write_iter+0x472/0xac0 [btrfs]
[ 9520.377875]  aio_write+0x25c/0x360
[ 9520.378106]  io_submit_one+0xaa0/0xdc0
[ 9520.378343]  __se_sys_io_submit+0xfa/0x2f0
[ 9520.378589]  __x64_sys_io_submit+0x43/0x50
[ 9520.378840]  do_syscall_64+0x7d/0x240
[ 9520.379081]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
[ 9520.379387]
[ 9520.379557] Freed by task 1802:
[ 9520.379782]  __kasan_slab_free+0x173/0x260
[ 9520.380028]  kasan_slab_free+0xe/0x10
[ 9520.380262]  kmem_cache_free+0xc1/0x2c0
[ 9520.380544]  btrfs_find_space_for_alloc+0x4cd/0x4e0 [btrfs]
[ 9520.380866]  find_free_extent+0xa99/0x17e0 [btrfs]
[ 9520.381166]  btrfs_reserve_extent+0xd5/0x1f0 [btrfs]
[ 9520.381474]  btrfs_get_blocks_direct+0x60b/0xbd0 [btrfs]
[ 9520.381761]  __blockdev_direct_IO+0x10ee/0x58a1
[ 9520.382059]  btrfs_direct_IO+0x25a/0x6d0 [btrfs]
[ 9520.382321]  generic_file_direct_write+0x11e/0x220
[ 9520.382623]  btrfs_file_write_iter+0x472/0xac0 [btrfs]
[ 9520.382904]  aio_write+0x25c/0x360
[ 9520.383172]  io_submit_one+0xaa0/0xdc0
[ 9520.383416]  __se_sys_io_submit+0xfa/0x2f0
[ 9520.383678]  __x64_sys_io_submit+0x43/0x50
[ 9520.383927]  do_syscall_64+0x7d/0x240
[ 9520.384165]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
[ 9520.384439]
[ 9520.384610] The buggy address belongs to the object at ffff8800b7ada500
                which belongs to the cache btrfs_free_space of size 72
[ 9520.385175] The buggy address is located 0 bytes inside of
                72-byte region [ffff8800b7ada500, ffff8800b7ada548)
[ 9520.385691] The buggy address belongs to the page:
[ 9520.385957] page:ffffea0002deb680 count:1 mapcount:0 mapping:ffff880108a1d700 index:0x0 compound_mapcount: 0
[ 9520.388030] flags: 0x8100(slab|head)
[ 9520.388281] raw: 0000000000008100 ffffea0002deb608 ffffea0002728808 ffff880108a1d700
[ 9520.388722] raw: 0000000000000000 0000000000130013 00000001ffffffff 0000000000000000
[ 9520.389169] page dumped because: kasan: bad access detected
[ 9520.389473]
[ 9520.389658] Memory state around the buggy address:
[ 9520.389943]  ffff8800b7ada400: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[ 9520.390368]  ffff8800b7ada480: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[ 9520.390796] >ffff8800b7ada500: fb fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc
[ 9520.391223]                    ^
[ 9520.391461]  ffff8800b7ada580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[ 9520.391885]  ffff8800b7ada600: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[ 9520.392313] ==================================================================
[ 9520.392772] BTRFS critical (device vdc): entry offset 2258497536, bytes 131072, bitmap no
[ 9520.393247] BUG: unable to handle kernel NULL pointer dereference at 0000000000000011
[ 9520.393705] PGD 800000010dbab067 P4D 800000010dbab067 PUD 107551067 PMD 0
[ 9520.394059] Oops: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN PTI
[ 9520.394378] CPU: 4 PID: 1721 Comm: btrfs-transacti Tainted: G    B        L    4.19.0-rc8-nbor torvalds#555
[ 9520.394858] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014
[ 9520.395350] RIP: 0010:rb_next+0x3c/0x90
[ 9520.396461] RSP: 0018:ffff8801074ff780 EFLAGS: 00010292
[ 9520.396762] RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffffffff81b5ac4c
[ 9520.397115] RDX: 0000000000000000 RSI: 0000000000000008 RDI: 0000000000000011
[ 9520.397468] RBP: ffff8801074ff7a0 R08: ffffed0021d64ccc R09: ffffed0021d64ccc
[ 9520.397821] R10: 0000000000000001 R11: ffffed0021d64ccb R12: ffff8800b91e0000
[ 9520.398188] R13: ffff8800a3ceba48 R14: ffff8800b627bf80 R15: 0000000000020000
[ 9520.398555] FS:  0000000000000000(0000) GS:ffff88010eb00000(0000) knlGS:0000000000000000
[ 9520.399007] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 9520.399335] CR2: 0000000000000011 CR3: 0000000106b52000 CR4: 00000000000006a0
[ 9520.399679] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 9520.400023] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 9520.400400] Call Trace:
[ 9520.400648]  btrfs_dump_free_space+0x146/0x160 [btrfs]
[ 9520.400974]  dump_space_info+0x2cd/0x310 [btrfs]
[ 9520.401287]  btrfs_reserve_extent+0x1ee/0x1f0 [btrfs]
[ 9520.401609]  __btrfs_prealloc_file_range+0x1cc/0x620 [btrfs]
[ 9520.401952]  ? btrfs_update_time+0x180/0x180 [btrfs]
[ 9520.402232]  ? _raw_spin_unlock+0x27/0x40
[ 9520.402522]  ? btrfs_alloc_data_chunk_ondemand+0x2c0/0x5c0 [btrfs]
[ 9520.402882]  btrfs_prealloc_file_range_trans+0x23/0x30 [btrfs]
[ 9520.403261]  cache_save_setup+0x42e/0x580 [btrfs]
[ 9520.403570]  ? btrfs_check_data_free_space+0xd0/0xd0 [btrfs]
[ 9520.403871]  ? lock_downgrade+0x2f0/0x2f0
[ 9520.404161]  ? btrfs_write_dirty_block_groups+0x11f/0x6e0 [btrfs]
[ 9520.404481]  ? kasan_check_read+0x11/0x20
[ 9520.404732]  ? do_raw_spin_unlock+0xa8/0x140
[ 9520.405026]  btrfs_write_dirty_block_groups+0x2af/0x6e0 [btrfs]
[ 9520.405375]  ? btrfs_start_dirty_block_groups+0x870/0x870 [btrfs]
[ 9520.405694]  ? do_raw_spin_unlock+0xa8/0x140
[ 9520.405958]  ? _raw_spin_unlock+0x27/0x40
[ 9520.406243]  ? btrfs_run_delayed_refs+0x1b8/0x230 [btrfs]
[ 9520.406574]  commit_cowonly_roots+0x4b9/0x610 [btrfs]
[ 9520.406899]  ? commit_fs_roots+0x350/0x350 [btrfs]
[ 9520.407253]  ? btrfs_run_delayed_refs+0x1b8/0x230 [btrfs]
[ 9520.407589]  btrfs_commit_transaction+0x5e5/0x10e0 [btrfs]
[ 9520.407925]  ? btrfs_apply_pending_changes+0x90/0x90 [btrfs]
[ 9520.408262]  ? start_transaction+0x168/0x6c0 [btrfs]
[ 9520.408582]  transaction_kthread+0x21c/0x240 [btrfs]
[ 9520.408870]  kthread+0x1d2/0x1f0
[ 9520.409138]  ? btrfs_cleanup_transaction+0xb50/0xb50 [btrfs]
[ 9520.409440]  ? kthread_park+0xb0/0xb0
[ 9520.409682]  ret_from_fork+0x3a/0x50
[ 9520.410508] Dumping ftrace buffer:
[ 9520.410764]    (ftrace buffer empty)
[ 9520.411007] CR2: 0000000000000011
[ 9520.411297] ---[ end trace 01a0863445cf360a ]---
[ 9520.411568] RIP: 0010:rb_next+0x3c/0x90
[ 9520.412644] RSP: 0018:ffff8801074ff780 EFLAGS: 00010292
[ 9520.412932] RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffffffff81b5ac4c
[ 9520.413274] RDX: 0000000000000000 RSI: 0000000000000008 RDI: 0000000000000011
[ 9520.413616] RBP: ffff8801074ff7a0 R08: ffffed0021d64ccc R09: ffffed0021d64ccc
[ 9520.414007] R10: 0000000000000001 R11: ffffed0021d64ccb R12: ffff8800b91e0000
[ 9520.414349] R13: ffff8800a3ceba48 R14: ffff8800b627bf80 R15: 0000000000020000
[ 9520.416074] FS:  0000000000000000(0000) GS:ffff88010eb00000(0000) knlGS:0000000000000000
[ 9520.416536] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 9520.416848] CR2: 0000000000000011 CR3: 0000000106b52000 CR4: 00000000000006a0
[ 9520.418477] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 9520.418846] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 9520.419204] Kernel panic - not syncing: Fatal exception
[ 9520.419666] Dumping ftrace buffer:
[ 9520.419930]    (ftrace buffer empty)
[ 9520.420168] Kernel Offset: disabled
[ 9520.420406] ---[ end Kernel panic - not syncing: Fatal exception ]---

Fix this by acquiring the respective lock before iterating the rbtree.

Reported-by: Nikolay Borisov <nborisov@suse.com>
CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Cc: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ddstreet pushed a commit to ddstreet/linux that referenced this pull request Feb 5, 2019
BugLink: http://bugs.launchpad.net/bugs/1810820

commit 9084cb6 upstream.

We were iterating a block group's free space cache rbtree without locking
first the lock that protects it (the free_space_ctl->free_space_offset
rbtree is protected by the free_space_ctl->tree_lock spinlock).

KASAN reported an use-after-free problem when iterating such a rbtree due
to a concurrent rbtree delete:

[ 9520.359168] ==================================================================
[ 9520.359656] BUG: KASAN: use-after-free in rb_next+0x13/0x90
[ 9520.359949] Read of size 8 at addr ffff8800b7ada500 by task btrfs-transacti/1721
[ 9520.360357]
[ 9520.360530] CPU: 4 PID: 1721 Comm: btrfs-transacti Tainted: G             L    4.19.0-rc8-nbor torvalds#555
[ 9520.360990] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014
[ 9520.362682] Call Trace:
[ 9520.362887]  dump_stack+0xa4/0xf5
[ 9520.363146]  print_address_description+0x78/0x280
[ 9520.363412]  kasan_report+0x263/0x390
[ 9520.363650]  ? rb_next+0x13/0x90
[ 9520.363873]  __asan_load8+0x54/0x90
[ 9520.364102]  rb_next+0x13/0x90
[ 9520.364380]  btrfs_dump_free_space+0x146/0x160 [btrfs]
[ 9520.364697]  dump_space_info+0x2cd/0x310 [btrfs]
[ 9520.364997]  btrfs_reserve_extent+0x1ee/0x1f0 [btrfs]
[ 9520.365310]  __btrfs_prealloc_file_range+0x1cc/0x620 [btrfs]
[ 9520.365646]  ? btrfs_update_time+0x180/0x180 [btrfs]
[ 9520.365923]  ? _raw_spin_unlock+0x27/0x40
[ 9520.366204]  ? btrfs_alloc_data_chunk_ondemand+0x2c0/0x5c0 [btrfs]
[ 9520.366549]  btrfs_prealloc_file_range_trans+0x23/0x30 [btrfs]
[ 9520.366880]  cache_save_setup+0x42e/0x580 [btrfs]
[ 9520.367220]  ? btrfs_check_data_free_space+0xd0/0xd0 [btrfs]
[ 9520.367518]  ? lock_downgrade+0x2f0/0x2f0
[ 9520.367799]  ? btrfs_write_dirty_block_groups+0x11f/0x6e0 [btrfs]
[ 9520.368104]  ? kasan_check_read+0x11/0x20
[ 9520.368349]  ? do_raw_spin_unlock+0xa8/0x140
[ 9520.368638]  btrfs_write_dirty_block_groups+0x2af/0x6e0 [btrfs]
[ 9520.368978]  ? btrfs_start_dirty_block_groups+0x870/0x870 [btrfs]
[ 9520.369282]  ? do_raw_spin_unlock+0xa8/0x140
[ 9520.369534]  ? _raw_spin_unlock+0x27/0x40
[ 9520.369811]  ? btrfs_run_delayed_refs+0x1b8/0x230 [btrfs]
[ 9520.370137]  commit_cowonly_roots+0x4b9/0x610 [btrfs]
[ 9520.370560]  ? commit_fs_roots+0x350/0x350 [btrfs]
[ 9520.370926]  ? btrfs_run_delayed_refs+0x1b8/0x230 [btrfs]
[ 9520.371285]  btrfs_commit_transaction+0x5e5/0x10e0 [btrfs]
[ 9520.371612]  ? btrfs_apply_pending_changes+0x90/0x90 [btrfs]
[ 9520.371943]  ? start_transaction+0x168/0x6c0 [btrfs]
[ 9520.372257]  transaction_kthread+0x21c/0x240 [btrfs]
[ 9520.372537]  kthread+0x1d2/0x1f0
[ 9520.372793]  ? btrfs_cleanup_transaction+0xb50/0xb50 [btrfs]
[ 9520.373090]  ? kthread_park+0xb0/0xb0
[ 9520.373329]  ret_from_fork+0x3a/0x50
[ 9520.373567]
[ 9520.373738] Allocated by task 1804:
[ 9520.373974]  kasan_kmalloc+0xff/0x180
[ 9520.374208]  kasan_slab_alloc+0x11/0x20
[ 9520.374447]  kmem_cache_alloc+0xfc/0x2d0
[ 9520.374731]  __btrfs_add_free_space+0x40/0x580 [btrfs]
[ 9520.375044]  unpin_extent_range+0x4f7/0x7a0 [btrfs]
[ 9520.375383]  btrfs_finish_extent_commit+0x15f/0x4d0 [btrfs]
[ 9520.375707]  btrfs_commit_transaction+0xb06/0x10e0 [btrfs]
[ 9520.376027]  btrfs_alloc_data_chunk_ondemand+0x237/0x5c0 [btrfs]
[ 9520.376365]  btrfs_check_data_free_space+0x81/0xd0 [btrfs]
[ 9520.376689]  btrfs_delalloc_reserve_space+0x25/0x80 [btrfs]
[ 9520.377018]  btrfs_direct_IO+0x42e/0x6d0 [btrfs]
[ 9520.377284]  generic_file_direct_write+0x11e/0x220
[ 9520.377587]  btrfs_file_write_iter+0x472/0xac0 [btrfs]
[ 9520.377875]  aio_write+0x25c/0x360
[ 9520.378106]  io_submit_one+0xaa0/0xdc0
[ 9520.378343]  __se_sys_io_submit+0xfa/0x2f0
[ 9520.378589]  __x64_sys_io_submit+0x43/0x50
[ 9520.378840]  do_syscall_64+0x7d/0x240
[ 9520.379081]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
[ 9520.379387]
[ 9520.379557] Freed by task 1802:
[ 9520.379782]  __kasan_slab_free+0x173/0x260
[ 9520.380028]  kasan_slab_free+0xe/0x10
[ 9520.380262]  kmem_cache_free+0xc1/0x2c0
[ 9520.380544]  btrfs_find_space_for_alloc+0x4cd/0x4e0 [btrfs]
[ 9520.380866]  find_free_extent+0xa99/0x17e0 [btrfs]
[ 9520.381166]  btrfs_reserve_extent+0xd5/0x1f0 [btrfs]
[ 9520.381474]  btrfs_get_blocks_direct+0x60b/0xbd0 [btrfs]
[ 9520.381761]  __blockdev_direct_IO+0x10ee/0x58a1
[ 9520.382059]  btrfs_direct_IO+0x25a/0x6d0 [btrfs]
[ 9520.382321]  generic_file_direct_write+0x11e/0x220
[ 9520.382623]  btrfs_file_write_iter+0x472/0xac0 [btrfs]
[ 9520.382904]  aio_write+0x25c/0x360
[ 9520.383172]  io_submit_one+0xaa0/0xdc0
[ 9520.383416]  __se_sys_io_submit+0xfa/0x2f0
[ 9520.383678]  __x64_sys_io_submit+0x43/0x50
[ 9520.383927]  do_syscall_64+0x7d/0x240
[ 9520.384165]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
[ 9520.384439]
[ 9520.384610] The buggy address belongs to the object at ffff8800b7ada500
                which belongs to the cache btrfs_free_space of size 72
[ 9520.385175] The buggy address is located 0 bytes inside of
                72-byte region [ffff8800b7ada500, ffff8800b7ada548)
[ 9520.385691] The buggy address belongs to the page:
[ 9520.385957] page:ffffea0002deb680 count:1 mapcount:0 mapping:ffff880108a1d700 index:0x0 compound_mapcount: 0
[ 9520.388030] flags: 0x8100(slab|head)
[ 9520.388281] raw: 0000000000008100 ffffea0002deb608 ffffea0002728808 ffff880108a1d700
[ 9520.388722] raw: 0000000000000000 0000000000130013 00000001ffffffff 0000000000000000
[ 9520.389169] page dumped because: kasan: bad access detected
[ 9520.389473]
[ 9520.389658] Memory state around the buggy address:
[ 9520.389943]  ffff8800b7ada400: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[ 9520.390368]  ffff8800b7ada480: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[ 9520.390796] >ffff8800b7ada500: fb fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc
[ 9520.391223]                    ^
[ 9520.391461]  ffff8800b7ada580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[ 9520.391885]  ffff8800b7ada600: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[ 9520.392313] ==================================================================
[ 9520.392772] BTRFS critical (device vdc): entry offset 2258497536, bytes 131072, bitmap no
[ 9520.393247] BUG: unable to handle kernel NULL pointer dereference at 0000000000000011
[ 9520.393705] PGD 800000010dbab067 P4D 800000010dbab067 PUD 107551067 PMD 0
[ 9520.394059] Oops: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN PTI
[ 9520.394378] CPU: 4 PID: 1721 Comm: btrfs-transacti Tainted: G    B        L    4.19.0-rc8-nbor torvalds#555
[ 9520.394858] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014
[ 9520.395350] RIP: 0010:rb_next+0x3c/0x90
[ 9520.396461] RSP: 0018:ffff8801074ff780 EFLAGS: 00010292
[ 9520.396762] RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffffffff81b5ac4c
[ 9520.397115] RDX: 0000000000000000 RSI: 0000000000000008 RDI: 0000000000000011
[ 9520.397468] RBP: ffff8801074ff7a0 R08: ffffed0021d64ccc R09: ffffed0021d64ccc
[ 9520.397821] R10: 0000000000000001 R11: ffffed0021d64ccb R12: ffff8800b91e0000
[ 9520.398188] R13: ffff8800a3ceba48 R14: ffff8800b627bf80 R15: 0000000000020000
[ 9520.398555] FS:  0000000000000000(0000) GS:ffff88010eb00000(0000) knlGS:0000000000000000
[ 9520.399007] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 9520.399335] CR2: 0000000000000011 CR3: 0000000106b52000 CR4: 00000000000006a0
[ 9520.399679] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 9520.400023] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 9520.400400] Call Trace:
[ 9520.400648]  btrfs_dump_free_space+0x146/0x160 [btrfs]
[ 9520.400974]  dump_space_info+0x2cd/0x310 [btrfs]
[ 9520.401287]  btrfs_reserve_extent+0x1ee/0x1f0 [btrfs]
[ 9520.401609]  __btrfs_prealloc_file_range+0x1cc/0x620 [btrfs]
[ 9520.401952]  ? btrfs_update_time+0x180/0x180 [btrfs]
[ 9520.402232]  ? _raw_spin_unlock+0x27/0x40
[ 9520.402522]  ? btrfs_alloc_data_chunk_ondemand+0x2c0/0x5c0 [btrfs]
[ 9520.402882]  btrfs_prealloc_file_range_trans+0x23/0x30 [btrfs]
[ 9520.403261]  cache_save_setup+0x42e/0x580 [btrfs]
[ 9520.403570]  ? btrfs_check_data_free_space+0xd0/0xd0 [btrfs]
[ 9520.403871]  ? lock_downgrade+0x2f0/0x2f0
[ 9520.404161]  ? btrfs_write_dirty_block_groups+0x11f/0x6e0 [btrfs]
[ 9520.404481]  ? kasan_check_read+0x11/0x20
[ 9520.404732]  ? do_raw_spin_unlock+0xa8/0x140
[ 9520.405026]  btrfs_write_dirty_block_groups+0x2af/0x6e0 [btrfs]
[ 9520.405375]  ? btrfs_start_dirty_block_groups+0x870/0x870 [btrfs]
[ 9520.405694]  ? do_raw_spin_unlock+0xa8/0x140
[ 9520.405958]  ? _raw_spin_unlock+0x27/0x40
[ 9520.406243]  ? btrfs_run_delayed_refs+0x1b8/0x230 [btrfs]
[ 9520.406574]  commit_cowonly_roots+0x4b9/0x610 [btrfs]
[ 9520.406899]  ? commit_fs_roots+0x350/0x350 [btrfs]
[ 9520.407253]  ? btrfs_run_delayed_refs+0x1b8/0x230 [btrfs]
[ 9520.407589]  btrfs_commit_transaction+0x5e5/0x10e0 [btrfs]
[ 9520.407925]  ? btrfs_apply_pending_changes+0x90/0x90 [btrfs]
[ 9520.408262]  ? start_transaction+0x168/0x6c0 [btrfs]
[ 9520.408582]  transaction_kthread+0x21c/0x240 [btrfs]
[ 9520.408870]  kthread+0x1d2/0x1f0
[ 9520.409138]  ? btrfs_cleanup_transaction+0xb50/0xb50 [btrfs]
[ 9520.409440]  ? kthread_park+0xb0/0xb0
[ 9520.409682]  ret_from_fork+0x3a/0x50
[ 9520.410508] Dumping ftrace buffer:
[ 9520.410764]    (ftrace buffer empty)
[ 9520.411007] CR2: 0000000000000011
[ 9520.411297] ---[ end trace 01a0863445cf360a ]---
[ 9520.411568] RIP: 0010:rb_next+0x3c/0x90
[ 9520.412644] RSP: 0018:ffff8801074ff780 EFLAGS: 00010292
[ 9520.412932] RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffffffff81b5ac4c
[ 9520.413274] RDX: 0000000000000000 RSI: 0000000000000008 RDI: 0000000000000011
[ 9520.413616] RBP: ffff8801074ff7a0 R08: ffffed0021d64ccc R09: ffffed0021d64ccc
[ 9520.414007] R10: 0000000000000001 R11: ffffed0021d64ccb R12: ffff8800b91e0000
[ 9520.414349] R13: ffff8800a3ceba48 R14: ffff8800b627bf80 R15: 0000000000020000
[ 9520.416074] FS:  0000000000000000(0000) GS:ffff88010eb00000(0000) knlGS:0000000000000000
[ 9520.416536] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 9520.416848] CR2: 0000000000000011 CR3: 0000000106b52000 CR4: 00000000000006a0
[ 9520.418477] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 9520.418846] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 9520.419204] Kernel panic - not syncing: Fatal exception
[ 9520.419666] Dumping ftrace buffer:
[ 9520.419930]    (ftrace buffer empty)
[ 9520.420168] Kernel Offset: disabled
[ 9520.420406] ---[ end Kernel panic - not syncing: Fatal exception ]---

Fix this by acquiring the respective lock before iterating the rbtree.

Reported-by: Nikolay Borisov <nborisov@suse.com>
CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>
Noltari pushed a commit to Noltari/linux that referenced this pull request Feb 11, 2019
commit 9084cb6 upstream.

We were iterating a block group's free space cache rbtree without locking
first the lock that protects it (the free_space_ctl->free_space_offset
rbtree is protected by the free_space_ctl->tree_lock spinlock).

KASAN reported an use-after-free problem when iterating such a rbtree due
to a concurrent rbtree delete:

[ 9520.359168] ==================================================================
[ 9520.359656] BUG: KASAN: use-after-free in rb_next+0x13/0x90
[ 9520.359949] Read of size 8 at addr ffff8800b7ada500 by task btrfs-transacti/1721
[ 9520.360357]
[ 9520.360530] CPU: 4 PID: 1721 Comm: btrfs-transacti Tainted: G             L    4.19.0-rc8-nbor torvalds#555
[ 9520.360990] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014
[ 9520.362682] Call Trace:
[ 9520.362887]  dump_stack+0xa4/0xf5
[ 9520.363146]  print_address_description+0x78/0x280
[ 9520.363412]  kasan_report+0x263/0x390
[ 9520.363650]  ? rb_next+0x13/0x90
[ 9520.363873]  __asan_load8+0x54/0x90
[ 9520.364102]  rb_next+0x13/0x90
[ 9520.364380]  btrfs_dump_free_space+0x146/0x160 [btrfs]
[ 9520.364697]  dump_space_info+0x2cd/0x310 [btrfs]
[ 9520.364997]  btrfs_reserve_extent+0x1ee/0x1f0 [btrfs]
[ 9520.365310]  __btrfs_prealloc_file_range+0x1cc/0x620 [btrfs]
[ 9520.365646]  ? btrfs_update_time+0x180/0x180 [btrfs]
[ 9520.365923]  ? _raw_spin_unlock+0x27/0x40
[ 9520.366204]  ? btrfs_alloc_data_chunk_ondemand+0x2c0/0x5c0 [btrfs]
[ 9520.366549]  btrfs_prealloc_file_range_trans+0x23/0x30 [btrfs]
[ 9520.366880]  cache_save_setup+0x42e/0x580 [btrfs]
[ 9520.367220]  ? btrfs_check_data_free_space+0xd0/0xd0 [btrfs]
[ 9520.367518]  ? lock_downgrade+0x2f0/0x2f0
[ 9520.367799]  ? btrfs_write_dirty_block_groups+0x11f/0x6e0 [btrfs]
[ 9520.368104]  ? kasan_check_read+0x11/0x20
[ 9520.368349]  ? do_raw_spin_unlock+0xa8/0x140
[ 9520.368638]  btrfs_write_dirty_block_groups+0x2af/0x6e0 [btrfs]
[ 9520.368978]  ? btrfs_start_dirty_block_groups+0x870/0x870 [btrfs]
[ 9520.369282]  ? do_raw_spin_unlock+0xa8/0x140
[ 9520.369534]  ? _raw_spin_unlock+0x27/0x40
[ 9520.369811]  ? btrfs_run_delayed_refs+0x1b8/0x230 [btrfs]
[ 9520.370137]  commit_cowonly_roots+0x4b9/0x610 [btrfs]
[ 9520.370560]  ? commit_fs_roots+0x350/0x350 [btrfs]
[ 9520.370926]  ? btrfs_run_delayed_refs+0x1b8/0x230 [btrfs]
[ 9520.371285]  btrfs_commit_transaction+0x5e5/0x10e0 [btrfs]
[ 9520.371612]  ? btrfs_apply_pending_changes+0x90/0x90 [btrfs]
[ 9520.371943]  ? start_transaction+0x168/0x6c0 [btrfs]
[ 9520.372257]  transaction_kthread+0x21c/0x240 [btrfs]
[ 9520.372537]  kthread+0x1d2/0x1f0
[ 9520.372793]  ? btrfs_cleanup_transaction+0xb50/0xb50 [btrfs]
[ 9520.373090]  ? kthread_park+0xb0/0xb0
[ 9520.373329]  ret_from_fork+0x3a/0x50
[ 9520.373567]
[ 9520.373738] Allocated by task 1804:
[ 9520.373974]  kasan_kmalloc+0xff/0x180
[ 9520.374208]  kasan_slab_alloc+0x11/0x20
[ 9520.374447]  kmem_cache_alloc+0xfc/0x2d0
[ 9520.374731]  __btrfs_add_free_space+0x40/0x580 [btrfs]
[ 9520.375044]  unpin_extent_range+0x4f7/0x7a0 [btrfs]
[ 9520.375383]  btrfs_finish_extent_commit+0x15f/0x4d0 [btrfs]
[ 9520.375707]  btrfs_commit_transaction+0xb06/0x10e0 [btrfs]
[ 9520.376027]  btrfs_alloc_data_chunk_ondemand+0x237/0x5c0 [btrfs]
[ 9520.376365]  btrfs_check_data_free_space+0x81/0xd0 [btrfs]
[ 9520.376689]  btrfs_delalloc_reserve_space+0x25/0x80 [btrfs]
[ 9520.377018]  btrfs_direct_IO+0x42e/0x6d0 [btrfs]
[ 9520.377284]  generic_file_direct_write+0x11e/0x220
[ 9520.377587]  btrfs_file_write_iter+0x472/0xac0 [btrfs]
[ 9520.377875]  aio_write+0x25c/0x360
[ 9520.378106]  io_submit_one+0xaa0/0xdc0
[ 9520.378343]  __se_sys_io_submit+0xfa/0x2f0
[ 9520.378589]  __x64_sys_io_submit+0x43/0x50
[ 9520.378840]  do_syscall_64+0x7d/0x240
[ 9520.379081]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
[ 9520.379387]
[ 9520.379557] Freed by task 1802:
[ 9520.379782]  __kasan_slab_free+0x173/0x260
[ 9520.380028]  kasan_slab_free+0xe/0x10
[ 9520.380262]  kmem_cache_free+0xc1/0x2c0
[ 9520.380544]  btrfs_find_space_for_alloc+0x4cd/0x4e0 [btrfs]
[ 9520.380866]  find_free_extent+0xa99/0x17e0 [btrfs]
[ 9520.381166]  btrfs_reserve_extent+0xd5/0x1f0 [btrfs]
[ 9520.381474]  btrfs_get_blocks_direct+0x60b/0xbd0 [btrfs]
[ 9520.381761]  __blockdev_direct_IO+0x10ee/0x58a1
[ 9520.382059]  btrfs_direct_IO+0x25a/0x6d0 [btrfs]
[ 9520.382321]  generic_file_direct_write+0x11e/0x220
[ 9520.382623]  btrfs_file_write_iter+0x472/0xac0 [btrfs]
[ 9520.382904]  aio_write+0x25c/0x360
[ 9520.383172]  io_submit_one+0xaa0/0xdc0
[ 9520.383416]  __se_sys_io_submit+0xfa/0x2f0
[ 9520.383678]  __x64_sys_io_submit+0x43/0x50
[ 9520.383927]  do_syscall_64+0x7d/0x240
[ 9520.384165]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
[ 9520.384439]
[ 9520.384610] The buggy address belongs to the object at ffff8800b7ada500
                which belongs to the cache btrfs_free_space of size 72
[ 9520.385175] The buggy address is located 0 bytes inside of
                72-byte region [ffff8800b7ada500, ffff8800b7ada548)
[ 9520.385691] The buggy address belongs to the page:
[ 9520.385957] page:ffffea0002deb680 count:1 mapcount:0 mapping:ffff880108a1d700 index:0x0 compound_mapcount: 0
[ 9520.388030] flags: 0x8100(slab|head)
[ 9520.388281] raw: 0000000000008100 ffffea0002deb608 ffffea0002728808 ffff880108a1d700
[ 9520.388722] raw: 0000000000000000 0000000000130013 00000001ffffffff 0000000000000000
[ 9520.389169] page dumped because: kasan: bad access detected
[ 9520.389473]
[ 9520.389658] Memory state around the buggy address:
[ 9520.389943]  ffff8800b7ada400: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[ 9520.390368]  ffff8800b7ada480: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[ 9520.390796] >ffff8800b7ada500: fb fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc
[ 9520.391223]                    ^
[ 9520.391461]  ffff8800b7ada580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[ 9520.391885]  ffff8800b7ada600: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[ 9520.392313] ==================================================================
[ 9520.392772] BTRFS critical (device vdc): entry offset 2258497536, bytes 131072, bitmap no
[ 9520.393247] BUG: unable to handle kernel NULL pointer dereference at 0000000000000011
[ 9520.393705] PGD 800000010dbab067 P4D 800000010dbab067 PUD 107551067 PMD 0
[ 9520.394059] Oops: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN PTI
[ 9520.394378] CPU: 4 PID: 1721 Comm: btrfs-transacti Tainted: G    B        L    4.19.0-rc8-nbor torvalds#555
[ 9520.394858] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014
[ 9520.395350] RIP: 0010:rb_next+0x3c/0x90
[ 9520.396461] RSP: 0018:ffff8801074ff780 EFLAGS: 00010292
[ 9520.396762] RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffffffff81b5ac4c
[ 9520.397115] RDX: 0000000000000000 RSI: 0000000000000008 RDI: 0000000000000011
[ 9520.397468] RBP: ffff8801074ff7a0 R08: ffffed0021d64ccc R09: ffffed0021d64ccc
[ 9520.397821] R10: 0000000000000001 R11: ffffed0021d64ccb R12: ffff8800b91e0000
[ 9520.398188] R13: ffff8800a3ceba48 R14: ffff8800b627bf80 R15: 0000000000020000
[ 9520.398555] FS:  0000000000000000(0000) GS:ffff88010eb00000(0000) knlGS:0000000000000000
[ 9520.399007] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 9520.399335] CR2: 0000000000000011 CR3: 0000000106b52000 CR4: 00000000000006a0
[ 9520.399679] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 9520.400023] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 9520.400400] Call Trace:
[ 9520.400648]  btrfs_dump_free_space+0x146/0x160 [btrfs]
[ 9520.400974]  dump_space_info+0x2cd/0x310 [btrfs]
[ 9520.401287]  btrfs_reserve_extent+0x1ee/0x1f0 [btrfs]
[ 9520.401609]  __btrfs_prealloc_file_range+0x1cc/0x620 [btrfs]
[ 9520.401952]  ? btrfs_update_time+0x180/0x180 [btrfs]
[ 9520.402232]  ? _raw_spin_unlock+0x27/0x40
[ 9520.402522]  ? btrfs_alloc_data_chunk_ondemand+0x2c0/0x5c0 [btrfs]
[ 9520.402882]  btrfs_prealloc_file_range_trans+0x23/0x30 [btrfs]
[ 9520.403261]  cache_save_setup+0x42e/0x580 [btrfs]
[ 9520.403570]  ? btrfs_check_data_free_space+0xd0/0xd0 [btrfs]
[ 9520.403871]  ? lock_downgrade+0x2f0/0x2f0
[ 9520.404161]  ? btrfs_write_dirty_block_groups+0x11f/0x6e0 [btrfs]
[ 9520.404481]  ? kasan_check_read+0x11/0x20
[ 9520.404732]  ? do_raw_spin_unlock+0xa8/0x140
[ 9520.405026]  btrfs_write_dirty_block_groups+0x2af/0x6e0 [btrfs]
[ 9520.405375]  ? btrfs_start_dirty_block_groups+0x870/0x870 [btrfs]
[ 9520.405694]  ? do_raw_spin_unlock+0xa8/0x140
[ 9520.405958]  ? _raw_spin_unlock+0x27/0x40
[ 9520.406243]  ? btrfs_run_delayed_refs+0x1b8/0x230 [btrfs]
[ 9520.406574]  commit_cowonly_roots+0x4b9/0x610 [btrfs]
[ 9520.406899]  ? commit_fs_roots+0x350/0x350 [btrfs]
[ 9520.407253]  ? btrfs_run_delayed_refs+0x1b8/0x230 [btrfs]
[ 9520.407589]  btrfs_commit_transaction+0x5e5/0x10e0 [btrfs]
[ 9520.407925]  ? btrfs_apply_pending_changes+0x90/0x90 [btrfs]
[ 9520.408262]  ? start_transaction+0x168/0x6c0 [btrfs]
[ 9520.408582]  transaction_kthread+0x21c/0x240 [btrfs]
[ 9520.408870]  kthread+0x1d2/0x1f0
[ 9520.409138]  ? btrfs_cleanup_transaction+0xb50/0xb50 [btrfs]
[ 9520.409440]  ? kthread_park+0xb0/0xb0
[ 9520.409682]  ret_from_fork+0x3a/0x50
[ 9520.410508] Dumping ftrace buffer:
[ 9520.410764]    (ftrace buffer empty)
[ 9520.411007] CR2: 0000000000000011
[ 9520.411297] ---[ end trace 01a0863445cf360a ]---
[ 9520.411568] RIP: 0010:rb_next+0x3c/0x90
[ 9520.412644] RSP: 0018:ffff8801074ff780 EFLAGS: 00010292
[ 9520.412932] RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffffffff81b5ac4c
[ 9520.413274] RDX: 0000000000000000 RSI: 0000000000000008 RDI: 0000000000000011
[ 9520.413616] RBP: ffff8801074ff7a0 R08: ffffed0021d64ccc R09: ffffed0021d64ccc
[ 9520.414007] R10: 0000000000000001 R11: ffffed0021d64ccb R12: ffff8800b91e0000
[ 9520.414349] R13: ffff8800a3ceba48 R14: ffff8800b627bf80 R15: 0000000000020000
[ 9520.416074] FS:  0000000000000000(0000) GS:ffff88010eb00000(0000) knlGS:0000000000000000
[ 9520.416536] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 9520.416848] CR2: 0000000000000011 CR3: 0000000106b52000 CR4: 00000000000006a0
[ 9520.418477] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 9520.418846] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 9520.419204] Kernel panic - not syncing: Fatal exception
[ 9520.419666] Dumping ftrace buffer:
[ 9520.419930]    (ftrace buffer empty)
[ 9520.420168] Kernel Offset: disabled
[ 9520.420406] ---[ end Kernel panic - not syncing: Fatal exception ]---

Fix this by acquiring the respective lock before iterating the rbtree.

Reported-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
fengguang pushed a commit to 0day-ci/linux that referenced this pull request Mar 12, 2021
This commit fixes the following checkpatch.pl warnings:

    WARNING: do not add new typedefs
    torvalds#95: FILE: hal/odm.h:95:
    +typedef struct _Rate_Adaptive_Table_ {

    WARNING: do not add new typedefs
    torvalds#99: FILE: hal/odm.h:99:
    +typedef struct _RX_High_Power_ {

    WARNING: do not add new typedefs
    torvalds#129: FILE: hal/odm.h:129:
    +typedef struct _SW_Antenna_Switch_ {

    WARNING: do not add new typedefs
    torvalds#181: FILE: hal/odm.h:181:
    +typedef struct _ODM_RATE_ADAPTIVE {

    WARNING: do not add new typedefs
    torvalds#280: FILE: hal/odm.h:280:
    +typedef enum tag_Dynamic_ODM_Support_Ability_Type {

    WARNING: do not add new typedefs
    torvalds#300: FILE: hal/odm.h:300:
    +typedef struct _ODM_STA_INFO {

    WARNING: do not add new typedefs
    torvalds#328: FILE: hal/odm.h:328:
    +typedef enum _ODM_Common_Info_Definition {

    WARNING: do not add new typedefs
    torvalds#418: FILE: hal/odm.h:418:
    +typedef enum _ODM_Support_Ability_Definition {

    WARNING: do not add new typedefs
    torvalds#449: FILE: hal/odm.h:449:
    +typedef enum tag_ODM_Support_Interface_Definition {

    WARNING: do not add new typedefs
    torvalds#455: FILE: hal/odm.h:455:
    +typedef enum tag_ODM_Support_IC_Type_Definition {

    WARNING: do not add new typedefs
    torvalds#460: FILE: hal/odm.h:460:
    +typedef enum tag_ODM_Cut_Version_Definition {

    WARNING: do not add new typedefs
    torvalds#475: FILE: hal/odm.h:475:
    +typedef enum tag_ODM_Fab_Version_Definition {

    WARNING: do not add new typedefs
    torvalds#484: FILE: hal/odm.h:484:
    +typedef enum tag_ODM_RF_Path_Bit_Definition {

    WARNING: do not add new typedefs
    torvalds#495: FILE: hal/odm.h:495:
    +typedef enum tag_ODM_RF_Type_Definition {

    WARNING: do not add new typedefs
    torvalds#516: FILE: hal/odm.h:516:
    +typedef enum tag_ODM_MAC_PHY_Mode_Definition {

    WARNING: do not add new typedefs
    torvalds#522: FILE: hal/odm.h:522:
    +typedef enum tag_BT_Coexist_Definition {

    WARNING: do not add new typedefs
    torvalds#530: FILE: hal/odm.h:530:
    +typedef enum tag_Operation_Mode_Definition {

    WARNING: do not add new typedefs
    torvalds#543: FILE: hal/odm.h:543:
    +typedef enum tag_Wireless_Mode_Definition {

    WARNING: do not add new typedefs
    torvalds#555: FILE: hal/odm.h:555:
    +typedef enum tag_Band_Type_Definition {

    WARNING: do not add new typedefs
    torvalds#563: FILE: hal/odm.h:563:
    +typedef enum tag_Secondary_Channel_Offset_Definition {

    WARNING: do not add new typedefs
    torvalds#570: FILE: hal/odm.h:570:
    +typedef enum tag_Security_Definition {

    WARNING: do not add new typedefs
    torvalds#582: FILE: hal/odm.h:582:
    +typedef enum tag_Bandwidth_Definition {

    WARNING: do not add new typedefs
    torvalds#593: FILE: hal/odm.h:593:
    +typedef enum tag_Board_Definition {

    WARNING: do not add new typedefs
    torvalds#605: FILE: hal/odm.h:605:
    +typedef enum tag_ODM_Package_Definition {

    WARNING: do not add new typedefs
    torvalds#612: FILE: hal/odm.h:612:
    +typedef enum tag_ODM_TYPE_GPA_Definition {

    WARNING: do not add new typedefs
    torvalds#617: FILE: hal/odm.h:617:
    +typedef enum tag_ODM_TYPE_APA_Definition {

    WARNING: do not add new typedefs
    torvalds#622: FILE: hal/odm.h:622:
    +typedef enum tag_ODM_TYPE_GLNA_Definition {

    WARNING: do not add new typedefs
    torvalds#629: FILE: hal/odm.h:629:
    +typedef enum tag_ODM_TYPE_ALNA_Definition {

    WARNING: do not add new typedefs
    torvalds#637: FILE: hal/odm.h:637:
    +typedef enum tag_CCA_Path {

    WARNING: do not add new typedefs
    torvalds#643: FILE: hal/odm.h:643:
    +typedef struct _ODM_RA_Info_ {

    WARNING: do not add new typedefs
    torvalds#675: FILE: hal/odm.h:675:
    +typedef struct _IQK_MATRIX_REGS_SETTING {

    WARNING: do not add new typedefs
    torvalds#683: FILE: hal/odm.h:683:
    +typedef struct ODM_RF_Calibration_Structure {

    WARNING: do not add new typedefs
    #788: FILE: hal/odm.h:788:
    +typedef struct _FAST_ANTENNA_TRAINNING_ {

    WARNING: do not add new typedefs
    torvalds#828: FILE: hal/odm.h:828:
    +typedef enum _FAT_STATE {

    WARNING: do not add new typedefs
    torvalds#833: FILE: hal/odm.h:833:
    +typedef enum _ANT_DIV_TYPE {

    WARNING: do not add new typedefs
    torvalds#843: FILE: hal/odm.h:843:
    +typedef struct _ODM_PATH_DIVERSITY_ {

    WARNING: do not add new typedefs
    torvalds#852: FILE: hal/odm.h:852:
    +typedef enum _BASEBAND_CONFIG_PHY_REG_PG_VALUE_TYPE {

    WARNING: do not add new typedefs
    torvalds#860: FILE: hal/odm.h:860:
    +typedef struct _ANT_DETECTED_INFO {

    WARNING: do not add new typedefs
    torvalds#870: FILE: hal/odm.h:870:
    +typedef  struct DM_Out_Source_Dynamic_Mechanism_Structure {

    WARNING: do not add new typedefs
    #1229: FILE: hal/odm.h:1229:
    + typedef enum _ODM_RF_CONTENT {

    WARNING: do not add new typedefs
    #1236: FILE: hal/odm.h:1236:
    +typedef enum _ODM_BB_Config_Type {

    WARNING: do not add new typedefs
    #1246: FILE: hal/odm.h:1246:
    +typedef enum _ODM_RF_Config_Type {

    WARNING: do not add new typedefs
    #1251: FILE: hal/odm.h:1251:
    +typedef enum _ODM_FW_Config_Type {

    WARNING: do not add new typedefs
    #1262: FILE: hal/odm.h:1262:
    +typedef enum _RT_STATUS {

    WARNING: do not add new typedefs
    #1319: FILE: hal/odm.h:1319:
    +typedef enum tag_1R_CCA_Type_Definition {

    WARNING: do not add new typedefs
    #1325: FILE: hal/odm.h:1325:
    +typedef enum tag_RF_Type_Definition {

    WARNING: do not add new typedefs
    #1334: FILE: hal/odm.h:1334:
    +typedef enum tag_SW_Antenna_Switch_Definition {

Signed-off-by: Marco Cesati <marco.cesati@gmail.com>
fengguang pushed a commit to 0day-ci/linux that referenced this pull request Mar 13, 2021
This commit fixes the following checkpatch.pl warnings:

    WARNING: do not add new typedefs
    torvalds#95: FILE: hal/odm.h:95:
    +typedef struct _Rate_Adaptive_Table_ {

    WARNING: do not add new typedefs
    torvalds#99: FILE: hal/odm.h:99:
    +typedef struct _RX_High_Power_ {

    WARNING: do not add new typedefs
    torvalds#129: FILE: hal/odm.h:129:
    +typedef struct _SW_Antenna_Switch_ {

    WARNING: do not add new typedefs
    torvalds#181: FILE: hal/odm.h:181:
    +typedef struct _ODM_RATE_ADAPTIVE {

    WARNING: do not add new typedefs
    torvalds#280: FILE: hal/odm.h:280:
    +typedef enum tag_Dynamic_ODM_Support_Ability_Type {

    WARNING: do not add new typedefs
    torvalds#300: FILE: hal/odm.h:300:
    +typedef struct _ODM_STA_INFO {

    WARNING: do not add new typedefs
    torvalds#328: FILE: hal/odm.h:328:
    +typedef enum _ODM_Common_Info_Definition {

    WARNING: do not add new typedefs
    torvalds#418: FILE: hal/odm.h:418:
    +typedef enum _ODM_Support_Ability_Definition {

    WARNING: do not add new typedefs
    torvalds#449: FILE: hal/odm.h:449:
    +typedef enum tag_ODM_Support_Interface_Definition {

    WARNING: do not add new typedefs
    torvalds#455: FILE: hal/odm.h:455:
    +typedef enum tag_ODM_Support_IC_Type_Definition {

    WARNING: do not add new typedefs
    torvalds#460: FILE: hal/odm.h:460:
    +typedef enum tag_ODM_Cut_Version_Definition {

    WARNING: do not add new typedefs
    torvalds#475: FILE: hal/odm.h:475:
    +typedef enum tag_ODM_Fab_Version_Definition {

    WARNING: do not add new typedefs
    torvalds#484: FILE: hal/odm.h:484:
    +typedef enum tag_ODM_RF_Path_Bit_Definition {

    WARNING: do not add new typedefs
    torvalds#495: FILE: hal/odm.h:495:
    +typedef enum tag_ODM_RF_Type_Definition {

    WARNING: do not add new typedefs
    torvalds#516: FILE: hal/odm.h:516:
    +typedef enum tag_ODM_MAC_PHY_Mode_Definition {

    WARNING: do not add new typedefs
    torvalds#522: FILE: hal/odm.h:522:
    +typedef enum tag_BT_Coexist_Definition {

    WARNING: do not add new typedefs
    torvalds#530: FILE: hal/odm.h:530:
    +typedef enum tag_Operation_Mode_Definition {

    WARNING: do not add new typedefs
    torvalds#543: FILE: hal/odm.h:543:
    +typedef enum tag_Wireless_Mode_Definition {

    WARNING: do not add new typedefs
    torvalds#555: FILE: hal/odm.h:555:
    +typedef enum tag_Band_Type_Definition {

    WARNING: do not add new typedefs
    torvalds#563: FILE: hal/odm.h:563:
    +typedef enum tag_Secondary_Channel_Offset_Definition {

    WARNING: do not add new typedefs
    torvalds#570: FILE: hal/odm.h:570:
    +typedef enum tag_Security_Definition {

    WARNING: do not add new typedefs
    torvalds#582: FILE: hal/odm.h:582:
    +typedef enum tag_Bandwidth_Definition {

    WARNING: do not add new typedefs
    torvalds#593: FILE: hal/odm.h:593:
    +typedef enum tag_Board_Definition {

    WARNING: do not add new typedefs
    torvalds#605: FILE: hal/odm.h:605:
    +typedef enum tag_ODM_Package_Definition {

    WARNING: do not add new typedefs
    torvalds#612: FILE: hal/odm.h:612:
    +typedef enum tag_ODM_TYPE_GPA_Definition {

    WARNING: do not add new typedefs
    torvalds#617: FILE: hal/odm.h:617:
    +typedef enum tag_ODM_TYPE_APA_Definition {

    WARNING: do not add new typedefs
    torvalds#622: FILE: hal/odm.h:622:
    +typedef enum tag_ODM_TYPE_GLNA_Definition {

    WARNING: do not add new typedefs
    torvalds#629: FILE: hal/odm.h:629:
    +typedef enum tag_ODM_TYPE_ALNA_Definition {

    WARNING: do not add new typedefs
    torvalds#637: FILE: hal/odm.h:637:
    +typedef enum tag_CCA_Path {

    WARNING: do not add new typedefs
    torvalds#643: FILE: hal/odm.h:643:
    +typedef struct _ODM_RA_Info_ {

    WARNING: do not add new typedefs
    torvalds#675: FILE: hal/odm.h:675:
    +typedef struct _IQK_MATRIX_REGS_SETTING {

    WARNING: do not add new typedefs
    torvalds#683: FILE: hal/odm.h:683:
    +typedef struct ODM_RF_Calibration_Structure {

    WARNING: do not add new typedefs
    #788: FILE: hal/odm.h:788:
    +typedef struct _FAST_ANTENNA_TRAINNING_ {

    WARNING: do not add new typedefs
    torvalds#828: FILE: hal/odm.h:828:
    +typedef enum _FAT_STATE {

    WARNING: do not add new typedefs
    torvalds#833: FILE: hal/odm.h:833:
    +typedef enum _ANT_DIV_TYPE {

    WARNING: do not add new typedefs
    torvalds#843: FILE: hal/odm.h:843:
    +typedef struct _ODM_PATH_DIVERSITY_ {

    WARNING: do not add new typedefs
    torvalds#852: FILE: hal/odm.h:852:
    +typedef enum _BASEBAND_CONFIG_PHY_REG_PG_VALUE_TYPE {

    WARNING: do not add new typedefs
    torvalds#860: FILE: hal/odm.h:860:
    +typedef struct _ANT_DETECTED_INFO {

    WARNING: do not add new typedefs
    torvalds#870: FILE: hal/odm.h:870:
    +typedef  struct DM_Out_Source_Dynamic_Mechanism_Structure {

    WARNING: do not add new typedefs
    #1229: FILE: hal/odm.h:1229:
    + typedef enum _ODM_RF_CONTENT {

    WARNING: do not add new typedefs
    #1236: FILE: hal/odm.h:1236:
    +typedef enum _ODM_BB_Config_Type {

    WARNING: do not add new typedefs
    #1246: FILE: hal/odm.h:1246:
    +typedef enum _ODM_RF_Config_Type {

    WARNING: do not add new typedefs
    #1251: FILE: hal/odm.h:1251:
    +typedef enum _ODM_FW_Config_Type {

    WARNING: do not add new typedefs
    #1262: FILE: hal/odm.h:1262:
    +typedef enum _RT_STATUS {

    WARNING: do not add new typedefs
    #1319: FILE: hal/odm.h:1319:
    +typedef enum tag_1R_CCA_Type_Definition {

    WARNING: do not add new typedefs
    #1325: FILE: hal/odm.h:1325:
    +typedef enum tag_RF_Type_Definition {

    WARNING: do not add new typedefs
    #1334: FILE: hal/odm.h:1334:
    +typedef enum tag_SW_Antenna_Switch_Definition {

Signed-off-by: Marco Cesati <marco.cesati@gmail.com>
Link: https://lore.kernel.org/r/20210312082638.25512-4-marco.cesati@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
fengguang pushed a commit to 0day-ci/linux that referenced this pull request Mar 15, 2021
This commit fixes the following checkpatch.pl errors:

    ERROR:POINTER_LOCATION: "foo * bar" should be "foo *bar"
    torvalds#535: FILE: ./hal/HalBtcOutSrc.h:535:
    +void EXhalbtcoutsrc_PowerOnSetting(struct BTC_COEXIST * pBtCoexist);

    ERROR:POINTER_LOCATION: "foo * bar" should be "foo *bar"
    torvalds#536: FILE: ./hal/HalBtcOutSrc.h:536:
    +void EXhalbtcoutsrc_InitHwConfig(struct BTC_COEXIST * pBtCoexist, u8 bWifiOnly);

    ERROR:POINTER_LOCATION: "foo * bar" should be "foo *bar"
    torvalds#537: FILE: ./hal/HalBtcOutSrc.h:537:
    +void EXhalbtcoutsrc_InitCoexDm(struct BTC_COEXIST * pBtCoexist);

    ERROR:POINTER_LOCATION: "foo * bar" should be "foo *bar"
    torvalds#538: FILE: ./hal/HalBtcOutSrc.h:538:
    +void EXhalbtcoutsrc_IpsNotify(struct BTC_COEXIST * pBtCoexist, u8 type);

    ERROR:POINTER_LOCATION: "foo * bar" should be "foo *bar"
    torvalds#539: FILE: ./hal/HalBtcOutSrc.h:539:
    +void EXhalbtcoutsrc_LpsNotify(struct BTC_COEXIST * pBtCoexist, u8 type);

    ERROR:POINTER_LOCATION: "foo * bar" should be "foo *bar"
    torvalds#540: FILE: ./hal/HalBtcOutSrc.h:540:
    +void EXhalbtcoutsrc_ScanNotify(struct BTC_COEXIST * pBtCoexist, u8 type);

    ERROR:POINTER_LOCATION: "foo * bar" should be "foo *bar"
    torvalds#541: FILE: ./hal/HalBtcOutSrc.h:541:
    +void EXhalbtcoutsrc_ConnectNotify(struct BTC_COEXIST * pBtCoexist, u8 action);

    ERROR:POINTER_LOCATION: "foo * bar" should be "foo *bar"
    torvalds#543: FILE: ./hal/HalBtcOutSrc.h:543:
    +	struct BTC_COEXIST * pBtCoexist, enum RT_MEDIA_STATUS mediaStatus

    ERROR:POINTER_LOCATION: "foo * bar" should be "foo *bar"
    torvalds#545: FILE: ./hal/HalBtcOutSrc.h:545:
    +void EXhalbtcoutsrc_SpecialPacketNotify(struct BTC_COEXIST * pBtCoexist, u8 pktType);

    ERROR:POINTER_LOCATION: "foo * bar" should be "foo *bar"
    torvalds#547: FILE: ./hal/HalBtcOutSrc.h:547:
    +	struct BTC_COEXIST * pBtCoexist, u8 *tmpBuf, u8 length

    ERROR:POINTER_LOCATION: "foo * bar" should be "foo *bar"
    torvalds#549: FILE: ./hal/HalBtcOutSrc.h:549:
    +void EXhalbtcoutsrc_HaltNotify(struct BTC_COEXIST * pBtCoexist);

    ERROR:POINTER_LOCATION: "foo * bar" should be "foo *bar"
    torvalds#550: FILE: ./hal/HalBtcOutSrc.h:550:
    +void EXhalbtcoutsrc_PnpNotify(struct BTC_COEXIST * pBtCoexist, u8 pnpState);

    ERROR:POINTER_LOCATION: "foo * bar" should be "foo *bar"
    torvalds#551: FILE: ./hal/HalBtcOutSrc.h:551:
    +void EXhalbtcoutsrc_Periodical(struct BTC_COEXIST * pBtCoexist);

    ERROR:POINTER_LOCATION: "foo * bar" should be "foo *bar"
    torvalds#555: FILE: ./hal/HalBtcOutSrc.h:555:
    +void EXhalbtcoutsrc_DisplayBtCoexInfo(struct BTC_COEXIST * pBtCoexist);

Signed-off-by: Marco Cesati <marcocesati@gmail.com>
fengguang pushed a commit to 0day-ci/linux that referenced this pull request Mar 16, 2021
This commit fixes the following checkpatch.pl errors:

    ERROR:POINTER_LOCATION: "foo * bar" should be "foo *bar"
    torvalds#535: FILE: ./hal/HalBtcOutSrc.h:535:
    +void EXhalbtcoutsrc_PowerOnSetting(struct BTC_COEXIST * pBtCoexist);

    ERROR:POINTER_LOCATION: "foo * bar" should be "foo *bar"
    torvalds#536: FILE: ./hal/HalBtcOutSrc.h:536:
    +void EXhalbtcoutsrc_InitHwConfig(struct BTC_COEXIST * pBtCoexist, u8 bWifiOnly);

    ERROR:POINTER_LOCATION: "foo * bar" should be "foo *bar"
    torvalds#537: FILE: ./hal/HalBtcOutSrc.h:537:
    +void EXhalbtcoutsrc_InitCoexDm(struct BTC_COEXIST * pBtCoexist);

    ERROR:POINTER_LOCATION: "foo * bar" should be "foo *bar"
    torvalds#538: FILE: ./hal/HalBtcOutSrc.h:538:
    +void EXhalbtcoutsrc_IpsNotify(struct BTC_COEXIST * pBtCoexist, u8 type);

    ERROR:POINTER_LOCATION: "foo * bar" should be "foo *bar"
    torvalds#539: FILE: ./hal/HalBtcOutSrc.h:539:
    +void EXhalbtcoutsrc_LpsNotify(struct BTC_COEXIST * pBtCoexist, u8 type);

    ERROR:POINTER_LOCATION: "foo * bar" should be "foo *bar"
    torvalds#540: FILE: ./hal/HalBtcOutSrc.h:540:
    +void EXhalbtcoutsrc_ScanNotify(struct BTC_COEXIST * pBtCoexist, u8 type);

    ERROR:POINTER_LOCATION: "foo * bar" should be "foo *bar"
    torvalds#541: FILE: ./hal/HalBtcOutSrc.h:541:
    +void EXhalbtcoutsrc_ConnectNotify(struct BTC_COEXIST * pBtCoexist, u8 action);

    ERROR:POINTER_LOCATION: "foo * bar" should be "foo *bar"
    torvalds#543: FILE: ./hal/HalBtcOutSrc.h:543:
    +	struct BTC_COEXIST * pBtCoexist, enum RT_MEDIA_STATUS mediaStatus

    ERROR:POINTER_LOCATION: "foo * bar" should be "foo *bar"
    torvalds#545: FILE: ./hal/HalBtcOutSrc.h:545:
    +void EXhalbtcoutsrc_SpecialPacketNotify(struct BTC_COEXIST * pBtCoexist, u8 pktType);

    ERROR:POINTER_LOCATION: "foo * bar" should be "foo *bar"
    torvalds#547: FILE: ./hal/HalBtcOutSrc.h:547:
    +	struct BTC_COEXIST * pBtCoexist, u8 *tmpBuf, u8 length

    ERROR:POINTER_LOCATION: "foo * bar" should be "foo *bar"
    torvalds#549: FILE: ./hal/HalBtcOutSrc.h:549:
    +void EXhalbtcoutsrc_HaltNotify(struct BTC_COEXIST * pBtCoexist);

    ERROR:POINTER_LOCATION: "foo * bar" should be "foo *bar"
    torvalds#550: FILE: ./hal/HalBtcOutSrc.h:550:
    +void EXhalbtcoutsrc_PnpNotify(struct BTC_COEXIST * pBtCoexist, u8 pnpState);

    ERROR:POINTER_LOCATION: "foo * bar" should be "foo *bar"
    torvalds#551: FILE: ./hal/HalBtcOutSrc.h:551:
    +void EXhalbtcoutsrc_Periodical(struct BTC_COEXIST * pBtCoexist);

    ERROR:POINTER_LOCATION: "foo * bar" should be "foo *bar"
    torvalds#555: FILE: ./hal/HalBtcOutSrc.h:555:
    +void EXhalbtcoutsrc_DisplayBtCoexInfo(struct BTC_COEXIST * pBtCoexist);

Reviewed-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Marco Cesati <marcocesati@gmail.com>
Link: https://lore.kernel.org/r/20210315170618.2566-7-marcocesati@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
lag-linaro pushed a commit to lag-linaro/linux that referenced this pull request Apr 12, 2021
commit 9084cb6 upstream.

We were iterating a block group's free space cache rbtree without locking
first the lock that protects it (the free_space_ctl->free_space_offset
rbtree is protected by the free_space_ctl->tree_lock spinlock).

KASAN reported an use-after-free problem when iterating such a rbtree due
to a concurrent rbtree delete:

[ 9520.359168] ==================================================================
[ 9520.359656] BUG: KASAN: use-after-free in rb_next+0x13/0x90
[ 9520.359949] Read of size 8 at addr ffff8800b7ada500 by task btrfs-transacti/1721
[ 9520.360357]
[ 9520.360530] CPU: 4 PID: 1721 Comm: btrfs-transacti Tainted: G             L    4.19.0-rc8-nbor torvalds#555
[ 9520.360990] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014
[ 9520.362682] Call Trace:
[ 9520.362887]  dump_stack+0xa4/0xf5
[ 9520.363146]  print_address_description+0x78/0x280
[ 9520.363412]  kasan_report+0x263/0x390
[ 9520.363650]  ? rb_next+0x13/0x90
[ 9520.363873]  __asan_load8+0x54/0x90
[ 9520.364102]  rb_next+0x13/0x90
[ 9520.364380]  btrfs_dump_free_space+0x146/0x160 [btrfs]
[ 9520.364697]  dump_space_info+0x2cd/0x310 [btrfs]
[ 9520.364997]  btrfs_reserve_extent+0x1ee/0x1f0 [btrfs]
[ 9520.365310]  __btrfs_prealloc_file_range+0x1cc/0x620 [btrfs]
[ 9520.365646]  ? btrfs_update_time+0x180/0x180 [btrfs]
[ 9520.365923]  ? _raw_spin_unlock+0x27/0x40
[ 9520.366204]  ? btrfs_alloc_data_chunk_ondemand+0x2c0/0x5c0 [btrfs]
[ 9520.366549]  btrfs_prealloc_file_range_trans+0x23/0x30 [btrfs]
[ 9520.366880]  cache_save_setup+0x42e/0x580 [btrfs]
[ 9520.367220]  ? btrfs_check_data_free_space+0xd0/0xd0 [btrfs]
[ 9520.367518]  ? lock_downgrade+0x2f0/0x2f0
[ 9520.367799]  ? btrfs_write_dirty_block_groups+0x11f/0x6e0 [btrfs]
[ 9520.368104]  ? kasan_check_read+0x11/0x20
[ 9520.368349]  ? do_raw_spin_unlock+0xa8/0x140
[ 9520.368638]  btrfs_write_dirty_block_groups+0x2af/0x6e0 [btrfs]
[ 9520.368978]  ? btrfs_start_dirty_block_groups+0x870/0x870 [btrfs]
[ 9520.369282]  ? do_raw_spin_unlock+0xa8/0x140
[ 9520.369534]  ? _raw_spin_unlock+0x27/0x40
[ 9520.369811]  ? btrfs_run_delayed_refs+0x1b8/0x230 [btrfs]
[ 9520.370137]  commit_cowonly_roots+0x4b9/0x610 [btrfs]
[ 9520.370560]  ? commit_fs_roots+0x350/0x350 [btrfs]
[ 9520.370926]  ? btrfs_run_delayed_refs+0x1b8/0x230 [btrfs]
[ 9520.371285]  btrfs_commit_transaction+0x5e5/0x10e0 [btrfs]
[ 9520.371612]  ? btrfs_apply_pending_changes+0x90/0x90 [btrfs]
[ 9520.371943]  ? start_transaction+0x168/0x6c0 [btrfs]
[ 9520.372257]  transaction_kthread+0x21c/0x240 [btrfs]
[ 9520.372537]  kthread+0x1d2/0x1f0
[ 9520.372793]  ? btrfs_cleanup_transaction+0xb50/0xb50 [btrfs]
[ 9520.373090]  ? kthread_park+0xb0/0xb0
[ 9520.373329]  ret_from_fork+0x3a/0x50
[ 9520.373567]
[ 9520.373738] Allocated by task 1804:
[ 9520.373974]  kasan_kmalloc+0xff/0x180
[ 9520.374208]  kasan_slab_alloc+0x11/0x20
[ 9520.374447]  kmem_cache_alloc+0xfc/0x2d0
[ 9520.374731]  __btrfs_add_free_space+0x40/0x580 [btrfs]
[ 9520.375044]  unpin_extent_range+0x4f7/0x7a0 [btrfs]
[ 9520.375383]  btrfs_finish_extent_commit+0x15f/0x4d0 [btrfs]
[ 9520.375707]  btrfs_commit_transaction+0xb06/0x10e0 [btrfs]
[ 9520.376027]  btrfs_alloc_data_chunk_ondemand+0x237/0x5c0 [btrfs]
[ 9520.376365]  btrfs_check_data_free_space+0x81/0xd0 [btrfs]
[ 9520.376689]  btrfs_delalloc_reserve_space+0x25/0x80 [btrfs]
[ 9520.377018]  btrfs_direct_IO+0x42e/0x6d0 [btrfs]
[ 9520.377284]  generic_file_direct_write+0x11e/0x220
[ 9520.377587]  btrfs_file_write_iter+0x472/0xac0 [btrfs]
[ 9520.377875]  aio_write+0x25c/0x360
[ 9520.378106]  io_submit_one+0xaa0/0xdc0
[ 9520.378343]  __se_sys_io_submit+0xfa/0x2f0
[ 9520.378589]  __x64_sys_io_submit+0x43/0x50
[ 9520.378840]  do_syscall_64+0x7d/0x240
[ 9520.379081]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
[ 9520.379387]
[ 9520.379557] Freed by task 1802:
[ 9520.379782]  __kasan_slab_free+0x173/0x260
[ 9520.380028]  kasan_slab_free+0xe/0x10
[ 9520.380262]  kmem_cache_free+0xc1/0x2c0
[ 9520.380544]  btrfs_find_space_for_alloc+0x4cd/0x4e0 [btrfs]
[ 9520.380866]  find_free_extent+0xa99/0x17e0 [btrfs]
[ 9520.381166]  btrfs_reserve_extent+0xd5/0x1f0 [btrfs]
[ 9520.381474]  btrfs_get_blocks_direct+0x60b/0xbd0 [btrfs]
[ 9520.381761]  __blockdev_direct_IO+0x10ee/0x58a1
[ 9520.382059]  btrfs_direct_IO+0x25a/0x6d0 [btrfs]
[ 9520.382321]  generic_file_direct_write+0x11e/0x220
[ 9520.382623]  btrfs_file_write_iter+0x472/0xac0 [btrfs]
[ 9520.382904]  aio_write+0x25c/0x360
[ 9520.383172]  io_submit_one+0xaa0/0xdc0
[ 9520.383416]  __se_sys_io_submit+0xfa/0x2f0
[ 9520.383678]  __x64_sys_io_submit+0x43/0x50
[ 9520.383927]  do_syscall_64+0x7d/0x240
[ 9520.384165]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
[ 9520.384439]
[ 9520.384610] The buggy address belongs to the object at ffff8800b7ada500
                which belongs to the cache btrfs_free_space of size 72
[ 9520.385175] The buggy address is located 0 bytes inside of
                72-byte region [ffff8800b7ada500, ffff8800b7ada548)
[ 9520.385691] The buggy address belongs to the page:
[ 9520.385957] page:ffffea0002deb680 count:1 mapcount:0 mapping:ffff880108a1d700 index:0x0 compound_mapcount: 0
[ 9520.388030] flags: 0x8100(slab|head)
[ 9520.388281] raw: 0000000000008100 ffffea0002deb608 ffffea0002728808 ffff880108a1d700
[ 9520.388722] raw: 0000000000000000 0000000000130013 00000001ffffffff 0000000000000000
[ 9520.389169] page dumped because: kasan: bad access detected
[ 9520.389473]
[ 9520.389658] Memory state around the buggy address:
[ 9520.389943]  ffff8800b7ada400: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[ 9520.390368]  ffff8800b7ada480: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[ 9520.390796] >ffff8800b7ada500: fb fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc
[ 9520.391223]                    ^
[ 9520.391461]  ffff8800b7ada580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[ 9520.391885]  ffff8800b7ada600: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[ 9520.392313] ==================================================================
[ 9520.392772] BTRFS critical (device vdc): entry offset 2258497536, bytes 131072, bitmap no
[ 9520.393247] BUG: unable to handle kernel NULL pointer dereference at 0000000000000011
[ 9520.393705] PGD 800000010dbab067 P4D 800000010dbab067 PUD 107551067 PMD 0
[ 9520.394059] Oops: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN PTI
[ 9520.394378] CPU: 4 PID: 1721 Comm: btrfs-transacti Tainted: G    B        L    4.19.0-rc8-nbor torvalds#555
[ 9520.394858] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014
[ 9520.395350] RIP: 0010:rb_next+0x3c/0x90
[ 9520.396461] RSP: 0018:ffff8801074ff780 EFLAGS: 00010292
[ 9520.396762] RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffffffff81b5ac4c
[ 9520.397115] RDX: 0000000000000000 RSI: 0000000000000008 RDI: 0000000000000011
[ 9520.397468] RBP: ffff8801074ff7a0 R08: ffffed0021d64ccc R09: ffffed0021d64ccc
[ 9520.397821] R10: 0000000000000001 R11: ffffed0021d64ccb R12: ffff8800b91e0000
[ 9520.398188] R13: ffff8800a3ceba48 R14: ffff8800b627bf80 R15: 0000000000020000
[ 9520.398555] FS:  0000000000000000(0000) GS:ffff88010eb00000(0000) knlGS:0000000000000000
[ 9520.399007] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 9520.399335] CR2: 0000000000000011 CR3: 0000000106b52000 CR4: 00000000000006a0
[ 9520.399679] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 9520.400023] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 9520.400400] Call Trace:
[ 9520.400648]  btrfs_dump_free_space+0x146/0x160 [btrfs]
[ 9520.400974]  dump_space_info+0x2cd/0x310 [btrfs]
[ 9520.401287]  btrfs_reserve_extent+0x1ee/0x1f0 [btrfs]
[ 9520.401609]  __btrfs_prealloc_file_range+0x1cc/0x620 [btrfs]
[ 9520.401952]  ? btrfs_update_time+0x180/0x180 [btrfs]
[ 9520.402232]  ? _raw_spin_unlock+0x27/0x40
[ 9520.402522]  ? btrfs_alloc_data_chunk_ondemand+0x2c0/0x5c0 [btrfs]
[ 9520.402882]  btrfs_prealloc_file_range_trans+0x23/0x30 [btrfs]
[ 9520.403261]  cache_save_setup+0x42e/0x580 [btrfs]
[ 9520.403570]  ? btrfs_check_data_free_space+0xd0/0xd0 [btrfs]
[ 9520.403871]  ? lock_downgrade+0x2f0/0x2f0
[ 9520.404161]  ? btrfs_write_dirty_block_groups+0x11f/0x6e0 [btrfs]
[ 9520.404481]  ? kasan_check_read+0x11/0x20
[ 9520.404732]  ? do_raw_spin_unlock+0xa8/0x140
[ 9520.405026]  btrfs_write_dirty_block_groups+0x2af/0x6e0 [btrfs]
[ 9520.405375]  ? btrfs_start_dirty_block_groups+0x870/0x870 [btrfs]
[ 9520.405694]  ? do_raw_spin_unlock+0xa8/0x140
[ 9520.405958]  ? _raw_spin_unlock+0x27/0x40
[ 9520.406243]  ? btrfs_run_delayed_refs+0x1b8/0x230 [btrfs]
[ 9520.406574]  commit_cowonly_roots+0x4b9/0x610 [btrfs]
[ 9520.406899]  ? commit_fs_roots+0x350/0x350 [btrfs]
[ 9520.407253]  ? btrfs_run_delayed_refs+0x1b8/0x230 [btrfs]
[ 9520.407589]  btrfs_commit_transaction+0x5e5/0x10e0 [btrfs]
[ 9520.407925]  ? btrfs_apply_pending_changes+0x90/0x90 [btrfs]
[ 9520.408262]  ? start_transaction+0x168/0x6c0 [btrfs]
[ 9520.408582]  transaction_kthread+0x21c/0x240 [btrfs]
[ 9520.408870]  kthread+0x1d2/0x1f0
[ 9520.409138]  ? btrfs_cleanup_transaction+0xb50/0xb50 [btrfs]
[ 9520.409440]  ? kthread_park+0xb0/0xb0
[ 9520.409682]  ret_from_fork+0x3a/0x50
[ 9520.410508] Dumping ftrace buffer:
[ 9520.410764]    (ftrace buffer empty)
[ 9520.411007] CR2: 0000000000000011
[ 9520.411297] ---[ end trace 01a0863445cf360a ]---
[ 9520.411568] RIP: 0010:rb_next+0x3c/0x90
[ 9520.412644] RSP: 0018:ffff8801074ff780 EFLAGS: 00010292
[ 9520.412932] RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffffffff81b5ac4c
[ 9520.413274] RDX: 0000000000000000 RSI: 0000000000000008 RDI: 0000000000000011
[ 9520.413616] RBP: ffff8801074ff7a0 R08: ffffed0021d64ccc R09: ffffed0021d64ccc
[ 9520.414007] R10: 0000000000000001 R11: ffffed0021d64ccb R12: ffff8800b91e0000
[ 9520.414349] R13: ffff8800a3ceba48 R14: ffff8800b627bf80 R15: 0000000000020000
[ 9520.416074] FS:  0000000000000000(0000) GS:ffff88010eb00000(0000) knlGS:0000000000000000
[ 9520.416536] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 9520.416848] CR2: 0000000000000011 CR3: 0000000106b52000 CR4: 00000000000006a0
[ 9520.418477] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 9520.418846] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 9520.419204] Kernel panic - not syncing: Fatal exception
[ 9520.419666] Dumping ftrace buffer:
[ 9520.419930]    (ftrace buffer empty)
[ 9520.420168] Kernel Offset: disabled
[ 9520.420406] ---[ end Kernel panic - not syncing: Fatal exception ]---

Fix this by acquiring the respective lock before iterating the rbtree.

Reported-by: Nikolay Borisov <nborisov@suse.com>
CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Cc: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Change-Id: I819f8104295ef5cd61dff7b8dc86b2ec56aa7056
ojeda pushed a commit to ojeda/linux that referenced this pull request Nov 20, 2021
rust: remove all usages of `try_new_and_init` and `pin_init_and_share`.
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2 participants