Dropouts at 192 kHz #12
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…optimizations
Recent GCC versions (e.g. GCC-4.7.2) perform optimizations based on
assumptions about the implementation of memset and similar functions.
The current ARM optimized memset code does not return the value of
its first argument, as is usually expected from standard implementations.
For instance in the following function:
void debug_mutex_lock_common(struct mutex *lock, struct mutex_waiter *waiter)
{
memset(waiter, MUTEX_DEBUG_INIT, sizeof(*waiter));
waiter->magic = waiter;
INIT_LIST_HEAD(&waiter->list);
}
compiled as:
800554d0 <debug_mutex_lock_common>:
800554d0: e92d4008 push {r3, lr}
800554d4: e1a00001 mov r0, r1
800554d8: e3a02010 mov r2, #16 ; 0x10
800554dc: e3a01011 mov r1, #17 ; 0x11
800554e0: eb04426e bl 80165ea0 <memset>
800554e4: e1a03000 mov r3, r0
800554e8: e583000c str r0, [r3, #12]
800554ec: e5830000 str r0, [r3]
800554f0: e5830004 str r0, [r3, #4]
800554f4: e8bd8008 pop {r3, pc}
GCC assumes memset returns the value of pointer 'waiter' in register r0; causing
register/memory corruptions.
This patch fixes the return value of the assembly version of memset.
It adds a 'mov' instruction and merges an additional load+store into
existing load/store instructions.
For ease of review, here is a breakdown of the patch into 4 simple steps:
Step 1
======
Perform the following substitutions:
ip -> r8, then
r0 -> ip,
and insert 'mov ip, r0' as the first statement of the function.
At this point, we have a memset() implementation returning the proper result,
but corrupting r8 on some paths (the ones that were using ip).
Step 2
======
Make sure r8 is saved and restored when (! CALGN(1)+0) == 1:
save r8:
- str lr, [sp, #-4]!
+ stmfd sp!, {r8, lr}
and restore r8 on both exit paths:
- ldmeqfd sp!, {pc} @ Now <64 bytes to go.
+ ldmeqfd sp!, {r8, pc} @ Now <64 bytes to go.
(...)
tst r2, #16
stmneia ip!, {r1, r3, r8, lr}
- ldr lr, [sp], #4
+ ldmfd sp!, {r8, lr}
Step 3
======
Make sure r8 is saved and restored when (! CALGN(1)+0) == 0:
save r8:
- stmfd sp!, {r4-r7, lr}
+ stmfd sp!, {r4-r8, lr}
and restore r8 on both exit paths:
bgt 3b
- ldmeqfd sp!, {r4-r7, pc}
+ ldmeqfd sp!, {r4-r8, pc}
(...)
tst r2, #16
stmneia ip!, {r4-r7}
- ldmfd sp!, {r4-r7, lr}
+ ldmfd sp!, {r4-r8, lr}
Step 4
======
Rewrite register list "r4-r7, r8" as "r4-r8".
Signed-off-by: Ivan Djelic <ivan.djelic@parrot.com>
Reviewed-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Dirk Behme <dirk.behme@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
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The following script will produce a kernel oops:
sudo ip netns add v
sudo ip netns exec v ip ad add 127.0.0.1/8 dev lo
sudo ip netns exec v ip link set lo up
sudo ip netns exec v ip ro add 224.0.0.0/4 dev lo
sudo ip netns exec v ip li add vxlan0 type vxlan id 42 group 239.1.1.1 dev lo
sudo ip netns exec v ip link set vxlan0 up
sudo ip netns del v
where inspect by gdb:
Program received signal SIGSEGV, Segmentation fault.
[Switching to Thread 107]
0xffffffffa0289e33 in ?? ()
(gdb) bt
#0 vxlan_leave_group (dev=0xffff88001bafa000) at drivers/net/vxlan.c:533
#1 vxlan_stop (dev=0xffff88001bafa000) at drivers/net/vxlan.c:1087
#2 0xffffffff812cc498 in __dev_close_many (head=head@entry=0xffff88001f2e7dc8) at net/core/dev.c:1299
#3 0xffffffff812cd920 in dev_close_many (head=head@entry=0xffff88001f2e7dc8) at net/core/dev.c:1335
#4 0xffffffff812cef31 in rollback_registered_many (head=head@entry=0xffff88001f2e7dc8) at net/core/dev.c:4851
#5 0xffffffff812cf040 in unregister_netdevice_many (head=head@entry=0xffff88001f2e7dc8) at net/core/dev.c:5752
#6 0xffffffff812cf1ba in default_device_exit_batch (net_list=0xffff88001f2e7e18) at net/core/dev.c:6170
#7 0xffffffff812cab27 in cleanup_net (work=<optimized out>) at net/core/net_namespace.c:302
#8 0xffffffff810540ef in process_one_work (worker=0xffff88001ba9ed40, work=0xffffffff8167d020) at kernel/workqueue.c:2157
#9 0xffffffff810549d0 in worker_thread (__worker=__worker@entry=0xffff88001ba9ed40) at kernel/workqueue.c:2276
#10 0xffffffff8105870c in kthread (_create=0xffff88001f2e5d68) at kernel/kthread.c:168
#11 <signal handler called>
#12 0x0000000000000000 in ?? ()
#13 0x0000000000000000 in ?? ()
(gdb) fr 0
#0 vxlan_leave_group (dev=0xffff88001bafa000) at drivers/net/vxlan.c:533
533 struct sock *sk = vn->sock->sk;
(gdb) l
528 static int vxlan_leave_group(struct net_device *dev)
529 {
530 struct vxlan_dev *vxlan = netdev_priv(dev);
531 struct vxlan_net *vn = net_generic(dev_net(dev), vxlan_net_id);
532 int err = 0;
533 struct sock *sk = vn->sock->sk;
534 struct ip_mreqn mreq = {
535 .imr_multiaddr.s_addr = vxlan->gaddr,
536 .imr_ifindex = vxlan->link,
537 };
(gdb) p vn->sock
$4 = (struct socket *) 0x0
The kernel calls `vxlan_exit_net` when deleting the netns before shutting down
vxlan interfaces. Later the removal of all vxlan interfaces, where `vn->sock`
is already gone causes the oops. so we should manually shutdown all interfaces
before deleting `vn->sock` as the patch does.
Signed-off-by: Zang MingJie <zealot0630@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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This patch fixes warnings due to missing lock on write error path. WARNING: at fs/hpfs/hpfs_fn.h:353 hpfs_truncate+0x75/0x80 [hpfs]() Hardware name: empty Pid: 26563, comm: dd Tainted: P O 3.9.4 #12 Call Trace: hpfs_truncate+0x75/0x80 [hpfs] hpfs_write_begin+0x84/0x90 [hpfs] _hpfs_bmap+0x10/0x10 [hpfs] generic_file_buffered_write+0x121/0x2c0 __generic_file_aio_write+0x1c7/0x3f0 generic_file_aio_write+0x7c/0x100 do_sync_write+0x98/0xd0 hpfs_file_write+0xd/0x50 [hpfs] vfs_write+0xa2/0x160 sys_write+0x51/0xa0 page_fault+0x22/0x30 system_call_fastpath+0x1a/0x1f Signed-off-by: Mikulas Patocka <mikulas@artax.karlin.mff.cuni.cz> Cc: stable@kernel.org # 2.6.39+ Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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If a too small MTU value is set with ioctl(HCISETACLMTU) or by a bogus controller, memory corruption happens due to a memcpy() call with negative length. Fix this crash on either incoming or outgoing connections with a MTU smaller than L2CAP_HDR_SIZE + L2CAP_CMD_HDR_SIZE: [ 46.885433] BUG: unable to handle kernel paging request at f56ad000 [ 46.888037] IP: [<c03d94cd>] memcpy+0x1d/0x40 [ 46.888037] *pdpt = 0000000000ac3001 *pde = 00000000373f8067 *pte = 80000000356ad060 [ 46.888037] Oops: 0002 [#1] SMP DEBUG_PAGEALLOC [ 46.888037] Modules linked in: hci_vhci bluetooth virtio_balloon i2c_piix4 uhci_hcd usbcore usb_common [ 46.888037] CPU: 0 PID: 1044 Comm: kworker/u3:0 Not tainted 3.10.0-rc1+ #12 [ 46.888037] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2007 [ 46.888037] Workqueue: hci0 hci_rx_work [bluetooth] [ 46.888037] task: f59b15b0 ti: f55c4000 task.ti: f55c4000 [ 46.888037] EIP: 0060:[<c03d94cd>] EFLAGS: 00010212 CPU: 0 [ 46.888037] EIP is at memcpy+0x1d/0x40 [ 46.888037] EAX: f56ac1c0 EBX: fffffff8 ECX: 3ffffc6e EDX: f55c5cf2 [ 46.888037] ESI: f55c6b32 EDI: f56ad000 EBP: f55c5c68 ESP: f55c5c5c [ 46.888037] DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068 [ 46.888037] CR0: 8005003b CR2: f56ad000 CR3: 3557d000 CR4: 000006f0 [ 46.888037] DR0: 00000000 DR1: 00000000 DR2: 00000000 DR3: 00000000 [ 46.888037] DR6: ffff0ff0 DR7: 00000400 [ 46.888037] Stack: [ 46.888037] fffffff8 00000010 00000003 f55c5cac f8c6a54c ffffffff f8c69eb2 00000000 [ 46.888037] f4783cdc f57f0070 f759c590 1001c580 00000003 0200000a 00000000 f5a88560 [ 46.888037] f5ba2600 f5a88560 00000041 00000000 f55c5d90 f8c6f4c7 00000008 f55c5cf2 [ 46.888037] Call Trace: [ 46.888037] [<f8c6a54c>] l2cap_send_cmd+0x1cc/0x230 [bluetooth] [ 46.888037] [<f8c69eb2>] ? l2cap_global_chan_by_psm+0x152/0x1a0 [bluetooth] [ 46.888037] [<f8c6f4c7>] l2cap_connect+0x3f7/0x540 [bluetooth] [ 46.888037] [<c019b37b>] ? trace_hardirqs_off+0xb/0x10 [ 46.888037] [<c01a0ff8>] ? mark_held_locks+0x68/0x110 [ 46.888037] [<c064ad20>] ? mutex_lock_nested+0x280/0x360 [ 46.888037] [<c064b9d9>] ? __mutex_unlock_slowpath+0xa9/0x150 [ 46.888037] [<c01a118c>] ? trace_hardirqs_on_caller+0xec/0x1b0 [ 46.888037] [<c064ad08>] ? mutex_lock_nested+0x268/0x360 [ 46.888037] [<c01a125b>] ? trace_hardirqs_on+0xb/0x10 [ 46.888037] [<f8c72f8d>] l2cap_recv_frame+0xb2d/0x1d30 [bluetooth] [ 46.888037] [<c01a0ff8>] ? mark_held_locks+0x68/0x110 [ 46.888037] [<c064b9d9>] ? __mutex_unlock_slowpath+0xa9/0x150 [ 46.888037] [<c01a118c>] ? trace_hardirqs_on_caller+0xec/0x1b0 [ 46.888037] [<f8c754f1>] l2cap_recv_acldata+0x2a1/0x320 [bluetooth] [ 46.888037] [<f8c491d8>] hci_rx_work+0x518/0x810 [bluetooth] [ 46.888037] [<f8c48df2>] ? hci_rx_work+0x132/0x810 [bluetooth] [ 46.888037] [<c0158979>] process_one_work+0x1a9/0x600 [ 46.888037] [<c01588fb>] ? process_one_work+0x12b/0x600 [ 46.888037] [<c015922e>] ? worker_thread+0x19e/0x320 [ 46.888037] [<c015922e>] ? worker_thread+0x19e/0x320 [ 46.888037] [<c0159187>] worker_thread+0xf7/0x320 [ 46.888037] [<c0159090>] ? rescuer_thread+0x290/0x290 [ 46.888037] [<c01602f8>] kthread+0xa8/0xb0 [ 46.888037] [<c0656777>] ret_from_kernel_thread+0x1b/0x28 [ 46.888037] [<c0160250>] ? flush_kthread_worker+0x120/0x120 [ 46.888037] Code: c3 90 8d 74 26 00 e8 63 fc ff ff eb e8 90 55 89 e5 83 ec 0c 89 5d f4 89 75 f8 89 7d fc 3e 8d 74 26 00 89 cb 89 c7 c1 e9 02 89 d6 <f3> a5 89 d9 83 e1 03 74 02 f3 a4 8b 5d f4 8b 75 f8 8b 7d fc 89 [ 46.888037] EIP: [<c03d94cd>] memcpy+0x1d/0x40 SS:ESP 0068:f55c5c5c [ 46.888037] CR2: 00000000f56ad000 [ 46.888037] ---[ end trace 0217c1f4d78714a9 ]--- Signed-off-by: Anderson Lizardo <anderson.lizardo@openbossa.org> Cc: stable@vger.kernel.org Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk> Signed-off-by: John W. Linville <linville@tuxdriver.com>
koalo
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…s struct file commit e4daf1f upstream. The following call chain: ------------------------------------------------------------ nfs4_get_vfs_file - nfsd_open - dentry_open - do_dentry_open - __get_file_write_access - get_write_access - return atomic_inc_unless_negative(&inode->i_writecount) ? 0 : -ETXTBSY; ------------------------------------------------------------ can result in the following state: ------------------------------------------------------------ struct nfs4_file { ... fi_fds = {0xffff880c1fa65c80, 0xffffffffffffffe6, 0x0}, fi_access = {{ counter = 0x1 }, { counter = 0x0 }}, ... ------------------------------------------------------------ 1) First time around, in nfs4_get_vfs_file() fp->fi_fds[O_WRONLY] is NULL, hence nfsd_open() is called where we get status set to an error and fp->fi_fds[O_WRONLY] to -ETXTBSY. Thus we do not reach nfs4_file_get_access() and fi_access[O_WRONLY] is not incremented. 2) Second time around, in nfs4_get_vfs_file() fp->fi_fds[O_WRONLY] is NOT NULL (-ETXTBSY), so nfsd_open() is NOT called, but nfs4_file_get_access() IS called and fi_access[O_WRONLY] is incremented. Thus we leave a landmine in the form of the nfs4_file data structure in an incorrect state. 3) Eventually, when __nfs4_file_put_access() is called it finds fi_access[O_WRONLY] being non-zero, it decrements it and calls nfs4_file_put_fd() which tries to fput -ETXTBSY. ------------------------------------------------------------ ... [exception RIP: fput+0x9] RIP: ffffffff81177fa9 RSP: ffff88062e365c90 RFLAGS: 00010282 RAX: ffff880c2b3d99cc RBX: ffff880c2b3d9978 RCX: 0000000000000002 RDX: dead000000100101 RSI: 0000000000000001 RDI: ffffffffffffffe6 RBP: ffff88062e365c90 R8: ffff88041fe797d8 R9: ffff88062e365d58 R10: 0000000000000008 R11: 0000000000000000 R12: 0000000000000001 R13: 0000000000000007 R14: 0000000000000000 R15: 0000000000000000 ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018 #9 [ffff88062e365c98] __nfs4_file_put_access at ffffffffa0562334 [nfsd] #10 [ffff88062e365cc8] nfs4_file_put_access at ffffffffa05623ab [nfsd] #11 [ffff88062e365ce8] free_generic_stateid at ffffffffa056634d [nfsd] #12 [ffff88062e365d18] release_open_stateid at ffffffffa0566e4b [nfsd] #13 [ffff88062e365d38] nfsd4_close at ffffffffa0567401 [nfsd] #14 [ffff88062e365d88] nfsd4_proc_compound at ffffffffa0557f28 [nfsd] #15 [ffff88062e365dd8] nfsd_dispatch at ffffffffa054543e [nfsd] #16 [ffff88062e365e18] svc_process_common at ffffffffa04ba5a4 [sunrpc] #17 [ffff88062e365e98] svc_process at ffffffffa04babe0 [sunrpc] #18 [ffff88062e365eb8] nfsd at ffffffffa0545b62 [nfsd] #19 [ffff88062e365ee8] kthread at ffffffff81090886 #20 [ffff88062e365f48] kernel_thread at ffffffff8100c14a ------------------------------------------------------------ Signed-off-by: Harshula Jayasuriya <harshula@redhat.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 057db84 upstream. Andrey reported the following report: ERROR: AddressSanitizer: heap-buffer-overflow on address ffff8800359c99f3 ffff8800359c99f3 is located 0 bytes to the right of 243-byte region [ffff8800359c9900, ffff8800359c99f3) Accessed by thread T13003: #0 ffffffff810dd2da (asan_report_error+0x32a/0x440) #1 ffffffff810dc6b0 (asan_check_region+0x30/0x40) #2 ffffffff810dd4d3 (__tsan_write1+0x13/0x20) #3 ffffffff811cd19e (ftrace_regex_release+0x1be/0x260) #4 ffffffff812a1065 (__fput+0x155/0x360) #5 ffffffff812a12de (____fput+0x1e/0x30) #6 ffffffff8111708d (task_work_run+0x10d/0x140) #7 ffffffff810ea043 (do_exit+0x433/0x11f0) #8 ffffffff810eaee4 (do_group_exit+0x84/0x130) #9 ffffffff810eafb1 (SyS_exit_group+0x21/0x30) #10 ffffffff81928782 (system_call_fastpath+0x16/0x1b) Allocated by thread T5167: #0 ffffffff810dc778 (asan_slab_alloc+0x48/0xc0) #1 ffffffff8128337c (__kmalloc+0xbc/0x500) #2 ffffffff811d9d54 (trace_parser_get_init+0x34/0x90) #3 ffffffff811cd7b3 (ftrace_regex_open+0x83/0x2e0) #4 ffffffff811cda7d (ftrace_filter_open+0x2d/0x40) #5 ffffffff8129b4ff (do_dentry_open+0x32f/0x430) #6 ffffffff8129b668 (finish_open+0x68/0xa0) #7 ffffffff812b66ac (do_last+0xb8c/0x1710) #8 ffffffff812b7350 (path_openat+0x120/0xb50) #9 ffffffff812b8884 (do_filp_open+0x54/0xb0) #10 ffffffff8129d36c (do_sys_open+0x1ac/0x2c0) #11 ffffffff8129d4b7 (SyS_open+0x37/0x50) #12 ffffffff81928782 (system_call_fastpath+0x16/0x1b) Shadow bytes around the buggy address: ffff8800359c9700: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd ffff8800359c9780: fd fd fd fd fd fd fd fd fa fa fa fa fa fa fa fa ffff8800359c9800: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa ffff8800359c9880: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa ffff8800359c9900: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 =>ffff8800359c9980: 00 00 00 00 00 00 00 00 00 00 00 00 00 00[03]fb ffff8800359c9a00: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa ffff8800359c9a80: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa ffff8800359c9b00: fa fa fa fa fa fa fa fa 00 00 00 00 00 00 00 00 ffff8800359c9b80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff8800359c9c00: 00 00 00 00 00 00 00 00 fa fa fa fa fa fa fa fa Shadow byte legend (one shadow byte represents 8 application bytes): Addressable: 00 Partially addressable: 01 02 03 04 05 06 07 Heap redzone: fa Heap kmalloc redzone: fb Freed heap region: fd Shadow gap: fe The out-of-bounds access happens on 'parser->buffer[parser->idx] = 0;' Although the crash happened in ftrace_regex_open() the real bug occurred in trace_get_user() where there's an incrementation to parser->idx without a check against the size. The way it is triggered is if userspace sends in 128 characters (EVENT_BUF_SIZE + 1), the loop that reads the last character stores it and then breaks out because there is no more characters. Then the last character is read to determine what to do next, and the index is incremented without checking size. Then the caller of trace_get_user() usually nulls out the last character with a zero, but since the index is equal to the size, it writes a nul character after the allocated space, which can corrupt memory. Luckily, only root user has write access to this file. Link: http://lkml.kernel.org/r/20131009222323.04fd1a0d@gandalf.local.home Reported-by: Andrey Konovalov <andreyknvl@google.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Several people reported the warning: "kernel BUG at kernel/timer.c:729!" and the stack trace is: #7 [ffff880214d25c10] mod_timer+501 at ffffffff8106d905 #8 [ffff880214d25c50] br_multicast_del_pg.isra.20+261 at ffffffffa0731d25 [bridge] #9 [ffff880214d25c80] br_multicast_disable_port+88 at ffffffffa0732948 [bridge] #10 [ffff880214d25cb0] br_stp_disable_port+154 at ffffffffa072bcca [bridge] #11 [ffff880214d25ce8] br_device_event+520 at ffffffffa072a4e8 [bridge] #12 [ffff880214d25d18] notifier_call_chain+76 at ffffffff8164aafc #13 [ffff880214d25d50] raw_notifier_call_chain+22 at ffffffff810858f6 #14 [ffff880214d25d60] call_netdevice_notifiers+45 at ffffffff81536aad #15 [ffff880214d25d80] dev_close_many+183 at ffffffff81536d17 #16 [ffff880214d25dc0] rollback_registered_many+168 at ffffffff81537f68 #17 [ffff880214d25de8] rollback_registered+49 at ffffffff81538101 #18 [ffff880214d25e10] unregister_netdevice_queue+72 at ffffffff815390d8 #19 [ffff880214d25e30] __tun_detach+272 at ffffffffa074c2f0 [tun] #20 [ffff880214d25e88] tun_chr_close+45 at ffffffffa074c4bd [tun] #21 [ffff880214d25ea8] __fput+225 at ffffffff8119b1f1 #22 [ffff880214d25ef0] ____fput+14 at ffffffff8119b3fe #23 [ffff880214d25f00] task_work_run+159 at ffffffff8107cf7f #24 [ffff880214d25f30] do_notify_resume+97 at ffffffff810139e1 #25 [ffff880214d25f50] int_signal+18 at ffffffff8164f292 this is due to I forgot to check if mp->timer is armed in br_multicast_del_pg(). This bug is introduced by commit 9f00b2e (bridge: only expire the mdb entry when query is received). Same for __br_mdb_del(). Tested-by: poma <pomidorabelisima@gmail.com> Reported-by: LiYonghua <809674045@qq.com> Reported-by: Robert Hancock <hancockrwd@gmail.com> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: Stephen Hemminger <stephen@networkplumber.org> Cc: "David S. Miller" <davem@davemloft.net> Signed-off-by: Cong Wang <amwang@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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When we try to open a file with O_TMPFILE flag, we will trigger a bug.
The root cause is that in ext4_orphan_add() we check ->i_nlink == 0 and
this check always fails because we set ->i_nlink = 1 in
inode_init_always(). We can use the following program to trigger it:
int main(int argc, char *argv[])
{
int fd;
fd = open(argv[1], O_TMPFILE, 0666);
if (fd < 0) {
perror("open ");
return -1;
}
close(fd);
return 0;
}
The oops message looks like this:
kernel BUG at fs/ext4/namei.c:2572!
invalid opcode: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC
Modules linked in: dlci bridge stp hidp cmtp kernelcapi l2tp_ppp l2tp_netlink l2tp_core sctp libcrc32c rfcomm tun fuse nfnetli
nk can_raw ipt_ULOG can_bcm x25 scsi_transport_iscsi ipx p8023 p8022 appletalk phonet psnap vmw_vsock_vmci_transport af_key vmw_vmci rose vsock atm can netrom ax25 af_rxrpc ir
da pppoe pppox ppp_generic slhc bluetooth nfc rfkill rds caif_socket caif crc_ccitt af_802154 llc2 llc snd_hda_codec_realtek snd_hda_intel snd_hda_codec serio_raw snd_pcm pcsp
kr edac_core snd_page_alloc snd_timer snd soundcore r8169 mii sr_mod cdrom pata_atiixp radeon backlight drm_kms_helper ttm
CPU: 1 PID: 1812571 Comm: trinity-child2 Not tainted 3.11.0-rc1+ #12
Hardware name: Gigabyte Technology Co., Ltd. GA-MA78GM-S2H/GA-MA78GM-S2H, BIOS F12a 04/23/2010
task: ffff88007dfe69a0 ti: ffff88010f7b6000 task.ti: ffff88010f7b6000
RIP: 0010:[<ffffffff8125ce69>] [<ffffffff8125ce69>] ext4_orphan_add+0x299/0x2b0
RSP: 0018:ffff88010f7b7cf8 EFLAGS: 00010202
RAX: 0000000000000000 RBX: ffff8800966d3020 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffff88007dfe70b8 RDI: 0000000000000001
RBP: ffff88010f7b7d40 R08: ffff880126a3c4e0 R09: ffff88010f7b7ca0
R10: 0000000000000000 R11: 0000000000000000 R12: ffff8801271fd668
R13: ffff8800966d2f78 R14: ffff88011d7089f0 R15: ffff88007dfe69a0
FS: 00007f70441a3740(0000) GS:ffff88012a800000(0000) knlGS:00000000f77c96c0
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000002834000 CR3: 0000000107964000 CR4: 00000000000007e0
DR0: 0000000000780000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Stack:
0000000000002000 00000020810b6dde 0000000000000000 ffff88011d46db00
ffff8800966d3020 ffff88011d7089f0 ffff88009c7f4c10 ffff88010f7b7f2c
ffff88007dfe69a0 ffff88010f7b7da8 ffffffff8125cfac ffff880100000004
Call Trace:
[<ffffffff8125cfac>] ext4_tmpfile+0x12c/0x180
[<ffffffff811cba78>] path_openat+0x238/0x700
[<ffffffff8100afc4>] ? native_sched_clock+0x24/0x80
[<ffffffff811cc647>] do_filp_open+0x47/0xa0
[<ffffffff811db73f>] ? __alloc_fd+0xaf/0x200
[<ffffffff811ba2e4>] do_sys_open+0x124/0x210
[<ffffffff81010725>] ? syscall_trace_enter+0x25/0x290
[<ffffffff811ba3ee>] SyS_open+0x1e/0x20
[<ffffffff816ca8d4>] tracesys+0xdd/0xe2
[<ffffffff81001001>] ? start_thread_common.constprop.6+0x1/0xa0
Code: 04 00 00 00 89 04 24 31 c0 e8 c4 77 04 00 e9 43 fe ff ff 66 25 00 d0 66 3d 00 80 0f 84 0e fe ff ff 83 7b 48 00 0f 84 04 fe ff ff <0f> 0b 49 8b 8c 24 50 07 00 00 e9 88 fe ff ff 0f 1f 84 00 00 00
Here we couldn't call clear_nlink() directly because in d_tmpfile() we
will call inode_dec_link_count() to decrease ->i_nlink. So this commit
tries to call d_tmpfile() before ext4_orphan_add() to fix this problem.
Reported-by: Dave Jones <davej@redhat.com>
Signed-off-by: Zheng Liu <wenqing.lz@taobao.com>
Tested-by: Darrick J. Wong <darrick.wong@oracle.com>
Tested-by: Dave Jones <davej@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
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…s struct file
The following call chain:
------------------------------------------------------------
nfs4_get_vfs_file
- nfsd_open
- dentry_open
- do_dentry_open
- __get_file_write_access
- get_write_access
- return atomic_inc_unless_negative(&inode->i_writecount) ? 0 : -ETXTBSY;
------------------------------------------------------------
can result in the following state:
------------------------------------------------------------
struct nfs4_file {
...
fi_fds = {0xffff880c1fa65c80, 0xffffffffffffffe6, 0x0},
fi_access = {{
counter = 0x1
}, {
counter = 0x0
}},
...
------------------------------------------------------------
1) First time around, in nfs4_get_vfs_file() fp->fi_fds[O_WRONLY] is
NULL, hence nfsd_open() is called where we get status set to an error
and fp->fi_fds[O_WRONLY] to -ETXTBSY. Thus we do not reach
nfs4_file_get_access() and fi_access[O_WRONLY] is not incremented.
2) Second time around, in nfs4_get_vfs_file() fp->fi_fds[O_WRONLY] is
NOT NULL (-ETXTBSY), so nfsd_open() is NOT called, but
nfs4_file_get_access() IS called and fi_access[O_WRONLY] is incremented.
Thus we leave a landmine in the form of the nfs4_file data structure in
an incorrect state.
3) Eventually, when __nfs4_file_put_access() is called it finds
fi_access[O_WRONLY] being non-zero, it decrements it and calls
nfs4_file_put_fd() which tries to fput -ETXTBSY.
------------------------------------------------------------
...
[exception RIP: fput+0x9]
RIP: ffffffff81177fa9 RSP: ffff88062e365c90 RFLAGS: 00010282
RAX: ffff880c2b3d99cc RBX: ffff880c2b3d9978 RCX: 0000000000000002
RDX: dead000000100101 RSI: 0000000000000001 RDI: ffffffffffffffe6
RBP: ffff88062e365c90 R8: ffff88041fe797d8 R9: ffff88062e365d58
R10: 0000000000000008 R11: 0000000000000000 R12: 0000000000000001
R13: 0000000000000007 R14: 0000000000000000 R15: 0000000000000000
ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018
#9 [ffff88062e365c98] __nfs4_file_put_access at ffffffffa0562334 [nfsd]
#10 [ffff88062e365cc8] nfs4_file_put_access at ffffffffa05623ab [nfsd]
#11 [ffff88062e365ce8] free_generic_stateid at ffffffffa056634d [nfsd]
#12 [ffff88062e365d18] release_open_stateid at ffffffffa0566e4b [nfsd]
#13 [ffff88062e365d38] nfsd4_close at ffffffffa0567401 [nfsd]
#14 [ffff88062e365d88] nfsd4_proc_compound at ffffffffa0557f28 [nfsd]
#15 [ffff88062e365dd8] nfsd_dispatch at ffffffffa054543e [nfsd]
#16 [ffff88062e365e18] svc_process_common at ffffffffa04ba5a4 [sunrpc]
#17 [ffff88062e365e98] svc_process at ffffffffa04babe0 [sunrpc]
#18 [ffff88062e365eb8] nfsd at ffffffffa0545b62 [nfsd]
#19 [ffff88062e365ee8] kthread at ffffffff81090886
#20 [ffff88062e365f48] kernel_thread at ffffffff8100c14a
------------------------------------------------------------
Cc: stable@vger.kernel.org
Signed-off-by: Harshula Jayasuriya <harshula@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
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[ 198.720048] ------------[ cut here ]------------ [ 198.720108] WARNING: CPU: 0 PID: 0 at net/sched/sch_generic.c:255 dev_watchdog+0x229/0x240() [ 198.720118] NETDEV WATCHDOG: eth0 (sis900): transmit queue 0 timed out [ 198.720125] Modules linked in: bridge stp llc dmfe sundance 3c59x sis900 mii [ 198.720159] CPU: 0 PID: 0 Comm: swapper Not tainted 3.11.0-rc3+ #12 [ 198.720167] Hardware name: System Manufacturer System Name/TUSI-M, BIOS ASUS TUSI-M ACPI BIOS Revision 1013 Beta 001 12/14/2001 [ 198.720175] 000000ff c13fa6b9 c169ddcc c12208d6 c169ddf8 c1031e4d c1664a84 c169de24 [ 198.720197] 00000000 c165f5ea 000000ff c13fa6b9 00000001 000000ff c1664a84 c169de10 [ 198.720217] c1031f13 00000009 c169de08 c1664a84 c169de24 c169de50 c13fa6b9 c165f5ea [ 198.720240] Call Trace: [ 198.720257] [<c13fa6b9>] ? dev_watchdog+0x229/0x240 [ 198.720274] [<c12208d6>] dump_stack+0x16/0x20 [ 198.720306] [<c1031e4d>] warn_slowpath_common+0x7d/0xa0 [ 198.720318] [<c13fa6b9>] ? dev_watchdog+0x229/0x240 [ 198.720330] [<c1031f13>] warn_slowpath_fmt+0x33/0x40 [ 198.720342] [<c13fa6b9>] dev_watchdog+0x229/0x240 [ 198.720357] [<c103f158>] call_timer_fn+0x78/0x150 [ 198.720369] [<c103f0e0>] ? internal_add_timer+0x40/0x40 [ 198.720381] [<c13fa490>] ? dev_init_scheduler+0xa0/0xa0 [ 198.720392] [<c103f33f>] run_timer_softirq+0x10f/0x200 [ 198.720412] [<c103954f>] ? __do_softirq+0x6f/0x210 [ 198.720424] [<c13fa490>] ? dev_init_scheduler+0xa0/0xa0 [ 198.720435] [<c1039598>] __do_softirq+0xb8/0x210 [ 198.720467] [<c14b54d2>] ? _raw_spin_unlock+0x22/0x30 [ 198.720484] [<c1003245>] ? handle_irq+0x25/0xd0 [ 198.720496] [<c1039c0c>] irq_exit+0x9c/0xb0 [ 198.720508] [<c14bc9d7>] do_IRQ+0x47/0x94 [ 198.720534] [<c1056078>] ? hrtimer_start+0x28/0x30 [ 198.720564] [<c14bc8b1>] common_interrupt+0x31/0x38 [ 198.720589] [<c1008692>] ? default_idle+0x22/0xa0 [ 198.720600] [<c10083c7>] arch_cpu_idle+0x17/0x30 [ 198.720631] [<c106d23d>] cpu_startup_entry+0xcd/0x180 [ 198.720643] [<c14ae30a>] rest_init+0xaa/0xb0 [ 198.720654] [<c14ae260>] ? reciprocal_value+0x50/0x50 [ 198.720668] [<c17044e0>] ? repair_env_string+0x60/0x60 [ 198.720679] [<c1704bda>] start_kernel+0x29a/0x350 [ 198.720690] [<c17044e0>] ? repair_env_string+0x60/0x60 [ 198.720721] [<c1704269>] i386_start_kernel+0x39/0xa0 [ 198.720729] ---[ end trace 81e0a6266f5c73a8 ]--- [ 198.720740] eth0: Transmit timeout, status 00000204 00000000 timer routine checks the link status and if it's up calls netif_carrier_on() allowing upper layer to start the tx queue even if the auto-negotiation process is not finished. Also remove ugly auto-negotiation check from the sis900_start_xmit() CC: Duan Fugang <B38611@freescale.com> CC: Ben Hutchings <bhutchings@solarflare.com> Signed-off-by: Denis Kirjanov <kda@linux-powerpc.org> Signed-off-by: David S. Miller <davem@davemloft.net>
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When booting secondary CPUs, announce_cpu() is called to show which cpu has been brought up. For example: [ 0.402751] smpboot: Booting Node 0, Processors #1 #2 #3 #4 #5 OK [ 0.525667] smpboot: Booting Node 1, Processors #6 #7 #8 #9 #10 #11 OK [ 0.755592] smpboot: Booting Node 0, Processors #12 #13 #14 #15 #16 #17 OK [ 0.890495] smpboot: Booting Node 1, Processors #18 #19 #20 #21 #22 #23 But the last "OK" is lost, because 'nr_cpu_ids-1' represents the maximum possible cpu id. It should use the maximum present cpu id in case not all CPUs booted up. Signed-off-by: Libin <huawei.libin@huawei.com> Cc: <guohanjun@huawei.com> Cc: <wangyijing@huawei.com> Cc: <fenghua.yu@intel.com> Cc: <paul.gortmaker@windriver.com> Link: http://lkml.kernel.org/r/1378378676-18276-1-git-send-email-huawei.libin@huawei.com [ tweaked the changelog, removed unnecessary line break, tweaked the format to align the fields vertically. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Injecting memory failure for page 0x19d0 at 0xb77d2000 MCE 0x19d0: non LRU page recovery: Ignored MCE: Software-unpoisoned page 0x19d0 BUG: Bad page state in process bash pfn:019d0 page:f3461a00 count:0 mapcount:0 mapping: (null) index:0x0 page flags: 0x40000404(referenced|reserved) Modules linked in: nfsd auth_rpcgss i915 nfs_acl nfs lockd video drm_kms_helper drm bnep rfcomm sunrpc bluetooth psmouse parport_pc ppdev lp serio_raw fscache parport gpio_ich lpc_ich mac_hid i2c_algo_bit tpm_tis wmi usb_storage hid_generic usbhid hid e1000e firewire_ohci firewire_core ahci ptp libahci pps_core crc_itu_t CPU: 3 PID: 2123 Comm: bash Not tainted 3.11.0-rc6+ #12 Hardware name: LENOVO 7034DD7/ , BIOS 9HKT47AUS 01//2012 00000000 00000000 e9625ea0 c15ec49b f3461a00 e9625eb8 c15ea119 c17cbf18 ef084314 000019d0 f3461a00 e9625ed8 c110dc8a f3461a00 00000001 00000000 f3461a00 40000404 00000000 e9625ef8 c110dcc1 f3461a00 f3461a00 000019d0 Call Trace: dump_stack+0x41/0x52 bad_page+0xcf/0xeb free_pages_prepare+0x12a/0x140 free_hot_cold_page+0x21/0x110 __put_single_page+0x21/0x30 put_page+0x25/0x40 unpoison_memory+0x107/0x200 hwpoison_unpoison+0x20/0x30 simple_attr_write+0xb6/0xd0 vfs_write+0xa0/0x1b0 SyS_write+0x4f/0x90 sysenter_do_call+0x12/0x22 Disabling lock debugging due to kernel taint Testcase: #define _GNU_SOURCE #include <stdlib.h> #include <stdio.h> #include <sys/mman.h> #include <unistd.h> #include <fcntl.h> #include <sys/types.h> #include <errno.h> #define PAGES_TO_TEST 1 #define PAGE_SIZE 4096 int main(void) { char *mem; mem = mmap(NULL, PAGES_TO_TEST * PAGE_SIZE, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, 0, 0); if (madvise(mem, PAGES_TO_TEST * PAGE_SIZE, MADV_HWPOISON) == -1) return -1; munmap(mem, PAGES_TO_TEST * PAGE_SIZE); return 0; } There is one page reference count for default empty zero page, madvise_hwpoison add another one by get_user_pages_fast. memory_hwpoison reduce one page reference count since it's a non LRU page. unpoison_memory release the last page reference count and free empty zero page to buddy system which is not correct since empty zero page has PG_reserved flag. This patch fix it by don't reduce the page reference count under 1 against empty zero page. Signed-off-by: Wanpeng Li <liwanp@linux.vnet.ibm.com> Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Andi Kleen <andi@firstfloor.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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When parsing lines from objdump a line containing source code starting
with a numeric label is mistaken for a line of disassembly starting with
a memory address.
Current validation fails to recognise that the "memory address" is out
of range and calculates an invalid offset which later causes this
segfault:
Program received signal SIGSEGV, Segmentation fault.
0x0000000000457315 in disasm__calc_percent (notes=0xc98970, evidx=0, offset=143705, end=2127526177, path=0x7fffffffbf50)
at util/annotate.c:631
631 hits += h->addr[offset++];
(gdb) bt
#0 0x0000000000457315 in disasm__calc_percent (notes=0xc98970, evidx=0, offset=143705, end=2127526177, path=0x7fffffffbf50)
at util/annotate.c:631
#1 0x00000000004d65e3 in annotate_browser__calc_percent (browser=0x7fffffffd130, evsel=0xa01da0) at ui/browsers/annotate.c:364
#2 0x00000000004d7433 in annotate_browser__run (browser=0x7fffffffd130, evsel=0xa01da0, hbt=0x0) at ui/browsers/annotate.c:672
#3 0x00000000004d80c9 in symbol__tui_annotate (sym=0xc989a0, map=0xa02660, evsel=0xa01da0, hbt=0x0) at ui/browsers/annotate.c:962
#4 0x00000000004d7aa0 in hist_entry__tui_annotate (he=0xdf73f0, evsel=0xa01da0, hbt=0x0) at ui/browsers/annotate.c:823
#5 0x00000000004dd648 in perf_evsel__hists_browse (evsel=0xa01da0, nr_events=1, helpline=
0x58b768 "For a higher level overview, try: perf report --sort comm,dso", ev_name=0xa02cd0 "cycles", left_exits=false, hbt=
0x0, min_pcnt=0, env=0xa011e0) at ui/browsers/hists.c:1659
#6 0x00000000004de372 in perf_evlist__tui_browse_hists (evlist=0xa01520, help=
0x58b768 "For a higher level overview, try: perf report --sort comm,dso", hbt=0x0, min_pcnt=0, env=0xa011e0)
at ui/browsers/hists.c:1950
#7 0x000000000042cf6b in __cmd_report (rep=0x7fffffffd6c0) at builtin-report.c:581
#8 0x000000000042e25d in cmd_report (argc=0, argv=0x7fffffffe4b0, prefix=0x0) at builtin-report.c:965
#9 0x000000000041a0e1 in run_builtin (p=0x801548, argc=1, argv=0x7fffffffe4b0) at perf.c:319
#10 0x000000000041a319 in handle_internal_command (argc=1, argv=0x7fffffffe4b0) at perf.c:376
#11 0x000000000041a465 in run_argv (argcp=0x7fffffffe38c, argv=0x7fffffffe380) at perf.c:420
#12 0x000000000041a707 in main (argc=1, argv=0x7fffffffe4b0) at perf.c:521
After the fix is applied the symbol can be annotated showing the
problematic line "1: rep"
copy_user_generic_string /usr/lib/debug/lib/modules/3.9.10-100.fc17.x86_64/vmlinux
*/
ENTRY(copy_user_generic_string)
CFI_STARTPROC
ASM_STAC
andl %edx,%edx
and %edx,%edx
jz 4f
je 37
cmpl $8,%edx
cmp $0x8,%edx
jb 2f /* less than 8 bytes, go to byte copy loop */
jb 33
ALIGN_DESTINATION
mov %edi,%ecx
and $0x7,%ecx
je 28
sub $0x8,%ecx
neg %ecx
sub %ecx,%edx
1a: mov (%rsi),%al
mov %al,(%rdi)
inc %rsi
inc %rdi
dec %ecx
jne 1a
movl %edx,%ecx
28: mov %edx,%ecx
shrl $3,%ecx
shr $0x3,%ecx
andl $7,%edx
and $0x7,%edx
1: rep
100.00 rep movsq %ds:(%rsi),%es:(%rdi)
movsq
2: movl %edx,%ecx
33: mov %edx,%ecx
3: rep
rep movsb %ds:(%rsi),%es:(%rdi)
movsb
4: xorl %eax,%eax
37: xor %eax,%eax
data32 xchg %ax,%ax
ASM_CLAC
ret
retq
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1379009721-27667-1-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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commit 057db84 upstream. Andrey reported the following report: ERROR: AddressSanitizer: heap-buffer-overflow on address ffff8800359c99f3 ffff8800359c99f3 is located 0 bytes to the right of 243-byte region [ffff8800359c9900, ffff8800359c99f3) Accessed by thread T13003: #0 ffffffff810dd2da (asan_report_error+0x32a/0x440) #1 ffffffff810dc6b0 (asan_check_region+0x30/0x40) #2 ffffffff810dd4d3 (__tsan_write1+0x13/0x20) #3 ffffffff811cd19e (ftrace_regex_release+0x1be/0x260) #4 ffffffff812a1065 (__fput+0x155/0x360) #5 ffffffff812a12de (____fput+0x1e/0x30) #6 ffffffff8111708d (task_work_run+0x10d/0x140) #7 ffffffff810ea043 (do_exit+0x433/0x11f0) #8 ffffffff810eaee4 (do_group_exit+0x84/0x130) #9 ffffffff810eafb1 (SyS_exit_group+0x21/0x30) #10 ffffffff81928782 (system_call_fastpath+0x16/0x1b) Allocated by thread T5167: #0 ffffffff810dc778 (asan_slab_alloc+0x48/0xc0) #1 ffffffff8128337c (__kmalloc+0xbc/0x500) #2 ffffffff811d9d54 (trace_parser_get_init+0x34/0x90) #3 ffffffff811cd7b3 (ftrace_regex_open+0x83/0x2e0) #4 ffffffff811cda7d (ftrace_filter_open+0x2d/0x40) #5 ffffffff8129b4ff (do_dentry_open+0x32f/0x430) #6 ffffffff8129b668 (finish_open+0x68/0xa0) #7 ffffffff812b66ac (do_last+0xb8c/0x1710) #8 ffffffff812b7350 (path_openat+0x120/0xb50) #9 ffffffff812b8884 (do_filp_open+0x54/0xb0) #10 ffffffff8129d36c (do_sys_open+0x1ac/0x2c0) #11 ffffffff8129d4b7 (SyS_open+0x37/0x50) #12 ffffffff81928782 (system_call_fastpath+0x16/0x1b) Shadow bytes around the buggy address: ffff8800359c9700: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd ffff8800359c9780: fd fd fd fd fd fd fd fd fa fa fa fa fa fa fa fa ffff8800359c9800: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa ffff8800359c9880: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa ffff8800359c9900: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 =>ffff8800359c9980: 00 00 00 00 00 00 00 00 00 00 00 00 00 00[03]fb ffff8800359c9a00: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa ffff8800359c9a80: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa ffff8800359c9b00: fa fa fa fa fa fa fa fa 00 00 00 00 00 00 00 00 ffff8800359c9b80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff8800359c9c00: 00 00 00 00 00 00 00 00 fa fa fa fa fa fa fa fa Shadow byte legend (one shadow byte represents 8 application bytes): Addressable: 00 Partially addressable: 01 02 03 04 05 06 07 Heap redzone: fa Heap kmalloc redzone: fb Freed heap region: fd Shadow gap: fe The out-of-bounds access happens on 'parser->buffer[parser->idx] = 0;' Although the crash happened in ftrace_regex_open() the real bug occurred in trace_get_user() where there's an incrementation to parser->idx without a check against the size. The way it is triggered is if userspace sends in 128 characters (EVENT_BUF_SIZE + 1), the loop that reads the last character stores it and then breaks out because there is no more characters. Then the last character is read to determine what to do next, and the index is incremented without checking size. Then the caller of trace_get_user() usually nulls out the last character with a zero, but since the index is equal to the size, it writes a nul character after the allocated space, which can corrupt memory. Luckily, only root user has write access to this file. Link: http://lkml.kernel.org/r/20131009222323.04fd1a0d@gandalf.local.home Reported-by: Andrey Konovalov <andreyknvl@google.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Copied from forum:
Hi,
I got the driver working with a Y2 dac and and an external bit clock and my own codec driver. It works great, thanks to all who contributed!
The one problem I had was that at higher sampling frequencies it started to have drop outs. Looking at hw_params I noticed that the buffer at 192kHz seemed smaller than the one for 44.1kHz:
root@pi:/proc/asound/sndrpibclkdiv/pcm0p/sub0# cat hw_params
access: RW_INTERLEAVED
format: S16_LE
subformat: STD
channels: 2
rate: 44100 (44100/1)
period_size: 4410
buffer_size: 22050
root@pi:/proc/asound/sndrpibclkdiv/pcm0p/sub0# cat hw_params
access: RW_INTERLEAVED
format: S32_LE
subformat: STD
channels: 2
rate: 192000 (192000/1)
period_size: 4096
buffer_size: 16384
Then I changed buffer_bytes_max in bcm2708-pcm.c:
.buffer_bytes_max = 1024 * 1024,
Now I get perfect playback at 192kHz and alsa reports the following:
root@pi:/proc/asound/sndrpibclkdiv/pcm0p/sub0# cat hw_params
access: RW_INTERLEAVED
format: S32_LE
subformat: STD
channels: 2
rate: 192000 (192000/1)
period_size: 8000
buffer_size: 96000
Leon
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