[syzbot] WARNING in snd_usbmidi_output_open

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: f8f60f322f06 Add linux-next specific files for 20221111
git tree: linux-next
console+strace: https://syzkaller.appspot.com/x/log.txt?x=12fe828e880000
kernel config: https://syzkaller.appspot.com/x/.config?x=85ba52c07cd97289
dashboard link: https://syzkaller.appspot.com/bug?extid=9abda841d636d86c41da
compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=160e91fa880000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=161d3e69880000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/6008df424195/disk-f8f60f32.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/394340525f66/vmlinux-f8f60f32.xz
kernel image: https://storage.googleapis.com/syzbot-assets/b13604a3343a/bzImage-f8f60f32.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+9abda8...@syzkaller.appspotmail.com

------------[ cut here ]------------
BUG?
WARNING: CPU: 0 PID: 5267 at sound/usb/midi.c:1137 snd_usbmidi_output_open+0xd8/0x410 sound/usb/midi.c:1137
Modules linked in:
CPU: 0 PID: 5267 Comm: syz-executor895 Not tainted 6.1.0-rc4-next-20221111-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
RIP: 0010:snd_usbmidi_output_open+0xd8/0x410 sound/usb/midi.c:1137
Code: 3c 02 00 0f 85 03 03 00 00 4d 8b be 10 02 00 00 4d 85 ff 0f 85 c8 00 00 00 e8 d4 92 25 fa 48 c7 c7 a0 6e f2 8a e8 02 da 04 02 <0f> 0b 41 bc fa ff ff ff e8 bb 92 25 fa 44 89 e0 48 83 c4 08 5b 5d
RSP: 0018:ffffc90003b7f3a0 EFLAGS: 00010282
RAX: 0000000000000000 RBX: ffff888146c8d000 RCX: 0000000000000000
RDX: ffff8880245d3a80 RSI: ffffffff81624e68 RDI: fffff5200076fe66
RBP: ffff88801ed9c900 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000080000000 R11: 0000000000000000 R12: ffff88814017cc00
R13: 0000000000000000 R14: ffff88802b1d5000 R15: 0000000000000000
FS: 00005555574d4300(0000) GS:ffff8880b9a00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f6ed57c3670 CR3: 0000000076149000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
open_substream+0x41d/0x8c0 sound/core/rawmidi.c:344
rawmidi_open_priv+0x591/0x6f0 sound/core/rawmidi.c:394
snd_rawmidi_kernel_open+0x1b5/0x270 sound/core/rawmidi.c:429
midisynth_use+0xee/0x270 sound/core/seq/seq_midi.c:215
subscribe_port sound/core/seq/seq_ports.c:412 [inline]
check_and_subscribe_port+0x89a/0xb80 sound/core/seq/seq_ports.c:495
snd_seq_port_connect+0x382/0x540 sound/core/seq/seq_ports.c:581
snd_seq_ioctl_subscribe_port+0x1fc/0x400 sound/core/seq/seq_clientmgr.c:1490
snd_seq_kernel_client_ctl+0x102/0x1c0 sound/core/seq/seq_clientmgr.c:2367
snd_seq_oss_midi_open+0x582/0x6e0 sound/core/seq/oss/seq_oss_midi.c:361
snd_seq_oss_synth_setup_midi+0x12d/0x530 sound/core/seq/oss/seq_oss_synth.c:269
snd_seq_oss_open+0x8b8/0xa70 sound/core/seq/oss/seq_oss_init.c:260
odev_open+0x6c/0x90 sound/core/seq/oss/seq_oss.c:128
soundcore_open+0x44e/0x620 sound/sound_core.c:593
chrdev_open+0x266/0x770 fs/char_dev.c:414
do_dentry_open+0x6cc/0x13f0 fs/open.c:882
do_open fs/namei.c:3557 [inline]
path_openat+0x1bbc/0x2a50 fs/namei.c:3713
do_filp_open+0x1b6/0x400 fs/namei.c:3740
do_sys_openat2+0x16d/0x4c0 fs/open.c:1310
do_sys_open fs/open.c:1326 [inline]
__do_sys_openat fs/open.c:1342 [inline]
__se_sys_openat fs/open.c:1337 [inline]
__x64_sys_openat+0x13f/0x1f0 fs/open.c:1337
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f496367ae39
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 b1 14 00 00 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 73 01 c3 48 c7 c1 c0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffc99e01aa8 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00000000000f4240 RCX: 00007f496367ae39
RDX: 0000000000020983 RSI: 0000000020000080 RDI: ffffffffffffff9c
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000001
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000000d066
R13: 00007ffc99e01abc R14: 00007ffc99e01ad0 R15: 00007ffc99e01ac0
</TASK>


---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzk...@googlegroups.com.

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
syzbot can test patches for this issue, for details see:
https://goo.gl/tpsmEJ#testing-patches

[syzbot]

syzbot has bisected this issue to:

commit 4f8ed19593872b710f27bbc3b7a9ce03310efc57
Author: Mark Brown <bro...@kernel.org>
Date: Thu Jun 2 13:10:58 2022 +0000

ASoC: tfa9879: Use modern ASoC DAI format terminology

bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=17433e69880000
start commit: f8f60f322f06 Add linux-next specific files for 20221111
git tree: linux-next
final oops: https://syzkaller.appspot.com/x/report.txt?x=14c33e69880000
console output: https://syzkaller.appspot.com/x/log.txt?x=10c33e69880000

kernel config: https://syzkaller.appspot.com/x/.config?x=85ba52c07cd97289
dashboard link: https://syzkaller.appspot.com/bug?extid=9abda841d636d86c41da

syz repro: https://syzkaller.appspot.com/x/repro.syz?x=160e91fa880000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=161d3e69880000

Reported-by: syzbot+9abda8...@syzkaller.appspotmail.com
Fixes: 4f8ed1959387 ("ASoC: tfa9879: Use modern ASoC DAI format terminology")

For information about bisection process see: https://goo.gl/tpsmEJ#bisection

[Mark Brown]

On Sat, Nov 12, 2022 at 05:29:21AM -0800, syzbot wrote:
> syzbot has bisected this issue to:
>
> commit 4f8ed19593872b710f27bbc3b7a9ce03310efc57
> Author: Mark Brown <bro...@kernel.org>
> Date: Thu Jun 2 13:10:58 2022 +0000
>
> ASoC: tfa9879: Use modern ASoC DAI format terminology

This bisection really doesn't seem credible for an issue in a different
driver... The tfa9879 is neither a USB nor MIDI device, and the commit
in question is a stylistic update.

[Takashi Iwai]

Yes, the bisection result is bogus.

And, the problem here is just a kernel WARNING produced by
snd_BUG_ON() macro usage, and the check itself is valid.
We just need to drop snd_BUG_ON() wrapping.

Will submit the fix later.


thanks,

Takashi