On Fri, Jan 05, 2018 at 09:47:01AM -0800, syzbot wrote:
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
Seems that this is fixed in sound/for-linus by:
#syz fix: ALSA: pcm: Abort properly at pending signal in OSS read/write loops