syzbot


WARNING in snd_pcm_drop

Status: fixed on 2020/10/07 06:25
Reported-by: syzbot+fcfd43cf5ae920a726dd@syzkaller.appspotmail.com
Fix commit: 37d933e8b41b fix regression in "epoll: Keep a reference on files added to the check list"
First crash: 663d, last: 663d

Fix bisection: fixed by (bisect log) :
commit 37d933e8b41b83bb8278815e366aec5a542b7e31
Author: Al Viro <viro@zeniv.linux.org.uk>
Date: Wed Sep 2 15:30:48 2020 +0000

  fix regression in "epoll: Keep a reference on files added to the check list"

similar bugs (1):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-4.14 WARNING in snd_pcm_drop syz done 1 663d 663d 1/1 fixed on 2020/10/05 13:19

Sample crash report:
batman_adv: batadv0: Interface activated: batadv_slave_1
IPv6: ADDRCONF(NETDEV_CHANGE): veth1_to_batadv: link becomes ready
Bluetooth: hci0: command 0x0409 tx timeout
Bluetooth: hci0: command 0x041b tx timeout
------------[ cut here ]------------
WARNING: CPU: 0 PID: 7645 at sound/core/pcm_native.c:1933 snd_pcm_drop.cold+0x11/0x1e sound/core/pcm_native.c:1933
Kernel panic - not syncing: panic_on_warn set ...

CPU: 0 PID: 7645 Comm: syz-executor.0 Not tainted 4.19.143-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1fc/0x2fe lib/dump_stack.c:118
 panic+0x26a/0x50e kernel/panic.c:186
 __warn.cold+0x20/0x61 kernel/panic.c:541
 report_bug+0x262/0x2b0 lib/bug.c:186
 fixup_bug arch/x86/kernel/traps.c:178 [inline]
 fixup_bug arch/x86/kernel/traps.c:173 [inline]
 do_error_trap+0x1d7/0x310 arch/x86/kernel/traps.c:296
 invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:1038
RIP: 0010:snd_pcm_drop.cold+0x11/0x1e sound/core/pcm_native.c:1933
Code: fb 48 c7 c7 40 91 22 88 e8 a5 44 c6 fb 0f 0b bb fa ff ff ff e9 c8 cb fe ff e8 75 38 db fb 48 c7 c7 40 91 22 88 e8 88 44 c6 fb <0f> 0b 41 bc fa ff ff ff e9 b4 ff fe ff e8 57 38 db fb 48 c7 c7 40
RSP: 0018:ffff88808fa67da0 EFLAGS: 00010282
RAX: 0000000000000024 RBX: ffff88809b258d80 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff8154d001 RDI: ffffed1011f4cfa6
RBP: ffff88809b258d80 R08: 0000000000000024 R09: 0000000000000000
R10: 0000000000000005 R11: 0000000000000000 R12: 0000000000000000
R13: 00000000ffffffff R14: ffff8880a0782140 R15: ffff8882167fb3f8
 snd_pcm_release_substream.part.0+0x21/0x2f0 sound/core/pcm_native.c:2407
 snd_pcm_release_substream sound/core/pcm_native.c:2404 [inline]
 snd_pcm_release+0xee/0x1f0 sound/core/pcm_native.c:2590
 __fput+0x2ce/0x890 fs/file_table.c:278
 task_work_run+0x148/0x1c0 kernel/task_work.c:113
 tracehook_notify_resume include/linux/tracehook.h:193 [inline]
 exit_to_usermode_loop+0x251/0x2a0 arch/x86/entry/common.c:167
 prepare_exit_to_usermode arch/x86/entry/common.c:198 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:271 [inline]
 do_syscall_64+0x538/0x620 arch/x86/entry/common.c:296
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45d5b9
Code: 5d b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 2b b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fd453ce4c78 EFLAGS: 00000246 ORIG_RAX: 00000000000000e9
RAX: 0000000000000000 RBX: 0000000000002ac0 RCX: 000000000045d5b9
RDX: 0000000000000005 RSI: 0000000000000001 RDI: 0000000000000006
RBP: 000000000118d028 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000020000040 R11: 0000000000000246 R12: 000000000118cfec
R13: 00007ffc2cf2136f R14: 00007fd453ce59c0 R15: 000000000118cfec
Kernel Offset: disabled
Rebooting in 86400 seconds..

Crashes (1):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-linux-4-19 2020/09/05 13:32 linux-4.19.y c37da90efff5 abf9ba4f .config log report syz