Re: [syzbot] [sound?] WARNING in snd_pcm_open

[Takashi Iwai <tiwai@xxxxxxx>]

On Tue, 27 Aug 2024 04:12:31 +0200,
syzbot wrote:
> 
> Hello,
> 
> syzbot found the following issue on:
> 
> HEAD commit:    6a7917c89f21 Add linux-next specific files for 20240822
> git tree:       linux-next
> console output: https://syzkaller.appspot.com/x/log.txt?x=11a72e09980000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=897bd7c53a10fcfc
> dashboard link: https://syzkaller.appspot.com/bug?extid=d2b696e5cb7a92fee831
> compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
> 
> Unfortunately, I don't have any reproducer for this issue yet.
> 
> Downloadable assets:
> disk image: https://storage.googleapis.com/syzbot-assets/47820545bc51/disk-6a7917c8.raw.xz
> vmlinux: https://storage.googleapis.com/syzbot-assets/e300f3a38860/vmlinux-6a7917c8.xz
> kernel image: https://storage.googleapis.com/syzbot-assets/9146afef58aa/bzImage-6a7917c8.xz
> 
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: syzbot+d2b696e5cb7a92fee831@xxxxxxxxxxxxxxxxxxxxxxxxx
> 
> ------------[ cut here ]------------
> do not call blocking ops when !TASK_RUNNING; state=1 set at [<ffffffff89468b6f>] snd_pcm_open+0x2ff/0x7a0 sound/core/pcm_native.c:2860
> WARNING: CPU: 1 PID: 5346 at kernel/sched/core.c:8556 __might_sleep+0xb9/0xe0 kernel/sched/core.c:8552
> Modules linked in:
> CPU: 1 UID: 0 PID: 5346 Comm: syz.4.9 Not tainted 6.11.0-rc4-next-20240822-syzkaller #0
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024
> RIP: 0010:__might_sleep+0xb9/0xe0 kernel/sched/core.c:8552
> Code: a1 0e 01 90 42 80 3c 23 00 74 08 48 89 ef e8 ce e6 97 00 48 8b 4d 00 48 c7 c7 c0 60 0a 8c 44 89 ee 48 89 ca e8 f8 02 f1 ff 90 <0f> 0b 90 90 eb b5 89 d9 80 e1 07 80 c1 03 38 c1 0f 8c 70 ff ff ff
> RSP: 0018:ffffc90004457408 EFLAGS: 00010246
> RAX: 0dea8fe797fdb300 RBX: 1ffff11002cf16ac RCX: 0000000000040000
> RDX: ffffc90009dd9000 RSI: 00000000000085c7 RDI: 00000000000085c8
> RBP: ffff88801678b560 R08: ffffffff8155a632 R09: fffffbfff1cfa364
> R10: dffffc0000000000 R11: fffffbfff1cfa364 R12: dffffc0000000000
> R13: 0000000000000001 R14: 0000000000000249 R15: ffffffff8c0ab880
> FS:  00007fa51e6226c0(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000
> CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 0000001b32715ff8 CR3: 00000000771dc000 CR4: 00000000003506f0
> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
> Call Trace:
>  <TASK>
>  __mutex_lock_common kernel/locking/mutex.c:585 [inline]
>  __mutex_lock+0xc1/0xd70 kernel/locking/mutex.c:752
>  snd_pcm_open+0x34b/0x7a0 sound/core/pcm_native.c:2863
>  snd_pcm_playback_open+0x6e/0xe0 sound/core/pcm_native.c:2810
>  chrdev_open+0x523/0x600 fs/char_dev.c:414
>  do_dentry_open+0x928/0x13f0 fs/open.c:959
>  vfs_open+0x3e/0x330 fs/open.c:1089
>  do_open fs/namei.c:3774 [inline]
>  path_openat+0x2c87/0x3590 fs/namei.c:3933
>  do_filp_open+0x235/0x490 fs/namei.c:3960
>  do_sys_openat2+0x13e/0x1d0 fs/open.c:1416
>  do_sys_open fs/open.c:1431 [inline]
>  __do_sys_openat fs/open.c:1447 [inline]
>  __se_sys_openat fs/open.c:1442 [inline]
>  __x64_sys_openat+0x247/0x2a0 fs/open.c:1442
>  do_syscall_x64 arch/x86/entry/common.c:52 [inline]
>  do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
>  entry_SYSCALL_64_after_hwframe+0x77/0x7f

So the call path is really early and nothing changed there recently.
It looks either false-positive or like a breakage in other lower level
code.


thanks,

Takashi

> RIP: 0033:0x7fa51d778810
> Code: 48 89 44 24 20 75 93 44 89 54 24 0c e8 19 8f 02 00 44 8b 54 24 0c 89 da 48 89 ee 41 89 c0 bf 9c ff ff ff b8 01 01 00 00 0f 05 <48> 3d 00 f0 ff ff 77 38 44 89 c7 89 44 24 0c e8 6c 8f 02 00 8b 44
> RSP: 002b:00007fa51e621b70 EFLAGS: 00000293 ORIG_RAX: 0000000000000101
> RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fa51d778810
> RDX: 0000000000000000 RSI: 00007fa51e621c10 RDI: 00000000ffffff9c
> RBP: 00007fa51e621c10 R08: 0000000000000000 R09: 0000000000000000
> R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000
> R13: 0000000000000000 R14: 00007fa51d915f80 R15: 00007ffc16ca31f8
>  </TASK>
> 
> 
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