WARNING in snd_info_get_line

syzbot
2020-07-20T07:35:57Z

Hello,

syzbot found the following issue on:

HEAD commit: f8456690 Merge tag 'clk-fixes-for-linus' of git://git.kern..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=11539507100000
kernel config: https://syzkaller.appspot.com/x/.config?x=e944500a36bc4d55
dashboard link: https://syzkaller.appspot.com/bug?extid=e42d0746c3c3699b6061
compiler: clang version 10.0.0 (https://github.com/llvm/llvm-project/ c2443155a0fb245c8f17f2c1c72b6ea391e86e81)
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1531c5ab100000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=17c399c7100000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+e42d0746c3c3699b6061@syzkaller.appspotmail.com

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WARNING: CPU: 1 PID: 6804 at sound/core/info.c:609 snd_info_get_line+0x3d0/0x450 sound/core/info.c:609
Kernel panic - not syncing: panic_on_warn set ...
CPU: 1 PID: 6804 Comm: syz-executor373 Not tainted 5.8.0-rc5-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+0x1f0/0x31e lib/dump_stack.c:118
panic+0x264/0x7a0 kernel/panic.c:231
__warn+0x227/0x250 kernel/panic.c:600
report_bug+0x1b1/0x2e0 lib/bug.c:198
handle_bug+0x42/0x80 arch/x86/kernel/traps.c:235
exc_invalid_op+0x16/0x40 arch/x86/kernel/traps.c:255
asm_exc_invalid_op+0x12/0x20 arch/x86/include/asm/idtentry.h:542
RIP: 0010:snd_info_get_line+0x3d0/0x450 sound/core/info.c:609
Code: 0f 85 84 00 00 00 41 c6 45 00 00 31 ed 89 e8 48 83 c4 40 5b 41 5c 41 5d 41 5e 41 5f 5d c3 e8 57 8a 3b fb eb 05 e8 50 8a 3b fb <0f> 0b bd 01 00 00 00 eb da 89 d9 80 e1 07 80 c1 03 38 c1 0f 8c a3
RSP: 0018:ffffc90001077a38 EFLAGS: 00010293
RAX: ffffffff86390470 RBX: 0000000000000080 RCX: ffff888096156500
RDX: 0000000000000000 RSI: ffffc90001077b10 RDI: ffff8880a1e30600
RBP: ffffc90001077bc8 R08: dffffc0000000000 R09: ffffed10429a6594
R10: ffffed10429a6594 R11: 0000000000000000 R12: ffff8880a2527908
R13: ffffc90001077b10 R14: 1ffff110143c60c0 R15: ffff8880a1e30600
snd_mixer_oss_proc_write+0x6d/0x670 sound/core/oss/mixer_oss.c:1179
snd_info_text_entry_release+0xdf/0x1c0 sound/core/info.c:409
close_pdeo+0x16c/0x310 fs/proc/inode.c:244
proc_reg_release+0x17c/0x1c0 fs/proc/inode.c:561
__fput+0x2f0/0x750 fs/file_table.c:281
task_work_run+0x137/0x1c0 kernel/task_work.c:135
exit_task_work include/linux/task_work.h:25 [inline]
do_exit+0x601/0x1f80 kernel/exit.c:805
do_group_exit+0x161/0x2d0 kernel/exit.c:903
__do_sys_exit_group+0x13/0x20 kernel/exit.c:914
__se_sys_exit_group+0x10/0x10 kernel/exit.c:912
__x64_sys_exit_group+0x37/0x40 kernel/exit.c:912
do_syscall_64+0x73/0xe0 arch/x86/entry/common.c:384
entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x43eeb8
Code: Bad RIP value.
RSP: 002b:00007ffce5a0e308 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000043eeb8
RDX: 0000000000000000 RSI: 000000000000003c RDI: 0000000000000000
RBP: 00000000004be6c8 R08: 00000000000000e7 R09: ffffffffffffffd0
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 00000000006d0180 R14: 0000000000000000 R15: 0000000000000000
Kernel Offset: disabled
Rebooting in 86400 seconds..

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