linux-next test error: WARNING in snd_pcm_plug_alloc

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit:    407b0a62 Add linux-next specific files for 20200312
git tree:       linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=14dd6545e00000
kernel config:  https://syzkaller.appspot.com/x/.config?x=d644875269fc730b
dashboard link: https://syzkaller.appspot.com/bug?extid=2a59ee7a9831b264f45e
compiler:       gcc (GCC) 9.0.0 20181231 (experimental)

Unfortunately, I don't have any reproducer for this crash yet.

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+2a59ee7a9831b264f45e at syzkaller.appspotmail.com

------------[ cut here ]------------
WARNING: CPU: 0 PID: 8559 at sound/core/oss/pcm_plugin.c:126 snd_pcm_plug_alloc+0x29a/0x330 sound/core/oss/pcm_plugin.c:126
Kernel panic - not syncing: panic_on_warn set ...
CPU: 0 PID: 8559 Comm: syz-fuzzer Not tainted 5.6.0-rc5-next-20200312-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+0x188/0x20d lib/dump_stack.c:118
 panic+0x2e3/0x75c kernel/panic.c:221
 __warn.cold+0x2f/0x35 kernel/panic.c:582
 report_bug+0x27b/0x2f0 lib/bug.c:195
 fixup_bug arch/x86/kernel/traps.c:175 [inline]
 fixup_bug arch/x86/kernel/traps.c:170 [inline]
 do_error_trap+0x12b/0x220 arch/x86/kernel/traps.c:267
 do_invalid_op+0x32/0x40 arch/x86/kernel/traps.c:286
 invalid_op+0x23/0x30 arch/x86/entry/entry_64.S:1027
RIP: 0010:snd_pcm_plug_alloc+0x29a/0x330 sound/core/oss/pcm_plugin.c:126
Code: ff ff 45 31 e4 e8 d6 4d 7f fb 44 89 e0 5b 5d 41 5c 41 5d 41 5e c3 e8 c5 4d 7f fb 0f 0b 41 bc fa ff ff ff eb e0 e8 b6 4d 7f fb <0f> 0b 41 bc fa ff ff ff eb d1 e8 a7 4d 7f fb 0f 0b 41 bc fa ff ff
RSP: 0018:ffffc90002317b88 EFLAGS: 00010293
RAX: ffff888093a7c200 RBX: ffff8880a4086000 RCX: ffffffff85f37886
RDX: 0000000000000000 RSI: ffffffff85f37a0a RDI: 0000000000000007
RBP: 0000000000000000 R08: ffff888093a7c200 R09: ffffed10132a791f
R10: ffff88809953c8f3 R11: ffffed10132a791e R12: ffff8880a4086058
R13: dffffc0000000000 R14: 0000000000000000 R15: ffff88809953c800
 snd_pcm_oss_change_params_locked+0x1c05/0x34b0 sound/core/oss/pcm_oss.c:1021
 snd_pcm_oss_change_params+0x76/0xd0 sound/core/oss/pcm_oss.c:1084
 snd_pcm_oss_make_ready+0xb7/0x170 sound/core/oss/pcm_oss.c:1143
 snd_pcm_oss_sync.isra.0+0x1be/0x7d0 sound/core/oss/pcm_oss.c:1708
 snd_pcm_oss_release+0x210/0x280 sound/core/oss/pcm_oss.c:2546
 __fput+0x2da/0x850 fs/file_table.c:280
 task_work_run+0xf4/0x1b0 kernel/task_work.c:123
 tracehook_notify_resume include/linux/tracehook.h:188 [inline]
 exit_to_usermode_loop+0x2fa/0x360 arch/x86/entry/common.c:165
 prepare_exit_to_usermode arch/x86/entry/common.c:196 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:279 [inline]
 do_syscall_64+0x6b1/0x7d0 arch/x86/entry/common.c:305
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x4afb40
Code: 8b 7c 24 10 48 8b 74 24 18 48 8b 54 24 20 49 c7 c2 00 00 00 00 49 c7 c0 00 00 00 00 49 c7 c1 00 00 00 00 48 8b 44 24 08 0f 05 <48> 3d 01 f0 ff ff 76 20 48 c7 44 24 28 ff ff ff ff 48 c7 44 24 30
RSP: 002b:000000c000213588 EFLAGS: 00000212 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 000000c00002c000 RCX: 00000000004afb40
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003
RBP: 000000c0002135c8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000212 R12: 0000000000000006
R13: 0000000000000005 R14: 0000000000000200 R15: 0000000000000000
Kernel Offset: disabled
Rebooting in 86400 seconds..


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