[alsa-devel] BUG: soft lockup (2)

5 Jan 2018


      syzkaller has found reproducer for the following crash on  
e1915c8195b38393005be9b74bfa6a3a367c83b3
git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/master
compiler: gcc (GCC) 7.1.1 20170620
.config is attached
Raw console output is attached.
C reproducer is attached
syzkaller reproducer is attached. See https://goo.gl/kgGztJ
for information about syzkaller reproducers
IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by:  
syzbot+f76f3c62dfadce022fd1c1deff15a61e09ac708a@syzkaller.appspotmail.com
It will help syzbot understand when the bug is fixed.
watchdog: BUG: soft lockup - CPU#0 stuck for 135s! [syzkaller670324:3527]
Modules linked in:
irq event stamp: 2531226
hardirqs last  enabled at (2531225): [<00000000f1ec093f>]  
snd_pcm_stream_unlock_irq+0x78/0xe0 sound/core/pcm_native.c:166
hardirqs last disabled at (2531226): [<000000003c6ef1cd>]  
apic_timer_interrupt+0xa4/0xb0 arch/x86/entry/entry_64.S:920
softirqs last  enabled at (41848): [<0000000081bd5f03>]  
__do_softirq+0x7a0/0xb85 kernel/softirq.c:311
softirqs last disabled at (41829): [<00000000d02c6d52>] invoke_softirq  
kernel/softirq.c:365 [inline]
softirqs last disabled at (41829): [<00000000d02c6d52>]  
irq_exit+0x1cc/0x200 kernel/softirq.c:405
CPU: 0 PID: 3527 Comm: syzkaller670324 Not tainted 4.15.0-rc6+ #158
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS  
Google 01/01/2011
RIP: 0010:memcpy+0x45/0x50 mm/kasan/kasan.c:305
RSP: 0018:ffff8801bf6676f0 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff11
RAX: ffffc9000137ba06 RBX: 0000000000000002 RCX: 0000000000000000
RDX: 0000000000000002 RSI: ffff8801bf6677da RDI: ffffc9000137ba08
RBP: ffff8801bf667708 R08: fffff5200026f741 R09: fffff5200026f741
R10: 0000000000000001 R11: fffff5200026f740 R12: ffffc9000137ba06
R13: ffff8801bf6677d8 R14: dffffc0000000000 R15: ffffc9000137ba06
FS:  0000000000000000(0000) GS:ffff8801db200000(0063) knlGS:00000000f7ec6b40
CS:  0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: 0000000020735ee0 CR3: 00000001bfba8002 CR4: 00000000001606f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
  memcpy include/linux/string.h:344 [inline]
  cvt_s16_to_native sound/core/oss/mulaw.c:164 [inline]
  mulaw_decode+0x52f/0x770 sound/core/oss/mulaw.c:195
  mulaw_transfer+0x222/0x270 sound/core/oss/mulaw.c:273
  snd_pcm_plug_write_transfer+0x22d/0x420 sound/core/oss/pcm_plugin.c:611
  snd_pcm_oss_write2+0x260/0x420 sound/core/oss/pcm_oss.c:1311
  snd_pcm_oss_write1 sound/core/oss/pcm_oss.c:1372 [inline]
  snd_pcm_oss_write+0x5fe/0x830 sound/core/oss/pcm_oss.c:2646
  __vfs_write+0xef/0x970 fs/read_write.c:480
  vfs_write+0x189/0x510 fs/read_write.c:544
  SYSC_write fs/read_write.c:589 [inline]
  SyS_write+0xef/0x220 fs/read_write.c:581
  do_syscall_32_irqs_on arch/x86/entry/common.c:327 [inline]
  do_fast_syscall_32+0x3ee/0xf9d arch/x86/entry/common.c:389
  entry_SYSENTER_compat+0x54/0x63 arch/x86/entry/entry_64_compat.S:129
RIP: 0023:0xf7f0cc79
RSP: 002b:00000000f7ec61fc EFLAGS: 00000246 ORIG_RAX: 0000000000000004
RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 0000000020735ee0
RDX: 00000000fffffee4 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00000000003d0f00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
Code: 89 de 31 d2 e8 9d f9 ff ff 48 8b 4d 08 48 89 de 4c 89 e7 ba 01 00 00  
00 e8 89 f9 ff ff 48 89 da 4c 89 ee 4c 89 e7 e8 7b eb c0 03 <5b> 41 5c 41  
5d 5d c3 0f 1f 40 00 89 f1 b8 00 10 00 00 55 48 d3