BUG: soft lockup in odev_write

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: cc0356d6a02e Merge tag 'x86_core_for_v5.16_rc1' of git://g..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=107f30dcb00000
kernel config: https://syzkaller.appspot.com/x/.config?x=84b0542e6d4e6962
dashboard link: https://syzkaller.appspot.com/bug?extid=f2e1a0a7a82d944c5a7a
compiler: aarch64-linux-gnu-gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.1
userspace arch: arm
CC: [alsa-...@alsa-project.org linux-...@vger.kernel.org pe...@perex.cz ti...@suse.com]

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

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+f2e1a0...@syzkaller.appspotmail.com

watchdog: BUG: soft lockup - CPU#0 stuck for 23s! [syz-executor.1:4442]
Modules linked in:
irq event stamp: 5042
hardirqs last enabled at (5041): [<ffff8000146b6f08>] __exit_to_kernel_mode arch/arm64/kernel/entry-common.c:82 [inline]
hardirqs last enabled at (5041): [<ffff8000146b6f08>] exit_to_kernel_mode+0x38/0x210 arch/arm64/kernel/entry-common.c:92
hardirqs last disabled at (5042): [<ffff8000146b9844>] __el1_irq arch/arm64/kernel/entry-common.c:435 [inline]
hardirqs last disabled at (5042): [<ffff8000146b9844>] el1_interrupt+0x24/0x50 arch/arm64/kernel/entry-common.c:460
softirqs last enabled at (828): [<ffff8000100109ec>] _stext+0x9ec/0x101c
softirqs last disabled at (805): [<ffff8000101626e8>] do_softirq_own_stack include/asm-generic/softirq_stack.h:10 [inline]
softirqs last disabled at (805): [<ffff8000101626e8>] invoke_softirq kernel/softirq.c:439 [inline]
softirqs last disabled at (805): [<ffff8000101626e8>] __irq_exit_rcu+0x3d8/0x5d0 kernel/softirq.c:636
CPU: 0 PID: 4442 Comm: syz-executor.1 Not tainted 5.15.0-syzkaller-04577-gcc0356d6a02e #0
Hardware name: linux,dummy-virt (DT)
pstate: 10000005 (nzcV daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : arch_local_irq_restore arch/arm64/include/asm/irqflags.h:131 [inline]
pc : lock_release+0x7a0/0xac0 kernel/locking/lockdep.c:5648
lr : __lock_release kernel/locking/lockdep.c:5302 [inline]
lr : lock_release+0x5f4/0xac0 kernel/locking/lockdep.c:5645
sp : ffff80001a4d79d0
x29: ffff80001a4d79d0 x28: 0000000000000001 x27: 0000000000000000
x26: ffff00001500beb0 x25: ffff800015bafcc0 x24: ffff80001069af18
x23: 0000000000000000 x22: 1ffff0000349af48 x21: ffff00001500b500
x20: ffff800054e98000 x19: ffff800015bafcc0 x18: 0000000000000000
x17: 0000000000000000 x16: 0000000000000000 x15: 00000000207a7c64
x14: 1ffff0000349af1e x13: 0000000000000168 x12: 1fffe00002a017d3
x11: 0000000000000007 x10: ffff00001500be9c x9 : 0000000000000000
x8 : ffff00001500bed8 x7 : 00000000f1f1f1f1 x6 : dfff800000000000
x5 : ffff70000349af48 x4 : 00000000f204f1f1 x3 : 1fffe0000d548f98
x2 : 0000000000000000 x1 : 00000000000000c0 x0 : 0000000000000080
Call trace:
arch_local_irq_restore arch/arm64/include/asm/irqflags.h:122 [inline]
lock_release+0x7a0/0xac0 kernel/locking/lockdep.c:5648
__might_fault mm/memory.c:5273 [inline]
__might_fault+0xfc/0x140 mm/memory.c:5258
_copy_from_user include/linux/uaccess.h:156 [inline]
copy_from_user include/linux/uaccess.h:192 [inline]
snd_seq_oss_write+0x12c/0x794 sound/core/seq/oss/seq_oss_rw.c:93
odev_write+0x38/0x74 sound/core/seq/oss/seq_oss.c:168
vfs_write+0x1cc/0x5c0 fs/read_write.c:588
ksys_write+0xec/0x1d0 fs/read_write.c:643
__do_sys_write fs/read_write.c:655 [inline]
__se_sys_write fs/read_write.c:652 [inline]
__arm64_sys_write+0x6c/0xa0 fs/read_write.c:652
__invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
invoke_syscall+0x6c/0x260 arch/arm64/kernel/syscall.c:52
el0_svc_common.constprop.0+0xc4/0x254 arch/arm64/kernel/syscall.c:142
do_el0_svc_compat+0x40/0x80 arch/arm64/kernel/syscall.c:187
el0_svc_compat+0x64/0x280 arch/arm64/kernel/entry-common.c:736
el0t_32_sync_handler+0x90/0x140 arch/arm64/kernel/entry-common.c:746
el0t_32_sync+0x1a4/0x1a8 arch/arm64/kernel/entry.S:577


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[syzbot]

Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.