lock error in do_sys_accept

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit: d2740109 Undo previous
git tree: netbsd
console output: https://syzkaller.appspot.com/x/log.txt?x=15baa33ca00000
dashboard link: https://syzkaller.appspot.com/bug?extid=77a6e06ea923e1eebe81

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+77a6e0...@syzkaller.appspotmail.com

[ 2638.4493921] panic: lock error: Mutex: mutex_vector_exit,761: assertion
failed: MUTEX_OWNER(mtx->mtx_owner) == curthread: lock 0xffffba8012f19080
cpu 0 lwp 0xffffba8011fc12a0
[ 2638.4748945] cpu0: Begin traceback...
[ 2638.4816655] vpanic() at netbsd:vpanic+0x214
[ 2638.4927603] snprintf() at netbsd:snprintf
[ 2638.5038640] lockdebug_abort() at netbsd:lockdebug_abort+0x153
[ 2638.5149704] mutex_vector_exit() at netbsd:mutex_vector_exit+0x1bc
[ 2638.5271808] do_sys_accept() at netbsd:do_sys_accept+0x346
[ 2638.5371835] sys_accept() at netbsd:sys_accept+0xac
[ 2638.5483555] sys___syscall() at netbsd:sys___syscall+0xe2
[ 2638.5705004] syscall() at netbsd:syscall+0x348
[ 2638.5705004] --- syscall (number 198) ---
[ 2638.5819802] 7e0be683f4aa:
[ 2638.5819802] cpu0: End traceback...

[ 2638.5819802] dumping to dev 4,1 (offset=0, size=0): not possible
[ 2638.5819802] rebooting...
SeaBIOS (version 1.8.2-20190308_060531-google)
Total RAM Size = 0x00000001e0000000 = 7680 MiB
CPUs found: 2 Max CPUs supported: 2
found virtio-scsi at 0:3
virtio-scsi vendor='Google' product='PersistentDisk' rev='1' type=0
removable=0
virtio-scsi blksize=512 sectors=4194304 = 2048 MiB
drive 0x000f29d0: PCHS=0/0/0 translation=lba LCHS=520/128/63 s=4194304
Booting from Hard Disk 0...

>> NetBSD/x86 BIOS Boot, Revision 5.10 (Tue Jul 17 14:59:51 UTC 2018) (from
>> NetBSD 8.0)
>> Memory: 639/3144640 k

1. Boot normally
2. Boot single user
3. Disable ACPI
4. Disable ACPI and SMP
5. Drop to boot prompt


---
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[syzbot]

syzbot has found a reproducer for the following crash on:

HEAD commit: d2740109 Undo previous
git tree: netbsd

console output: https://syzkaller.appspot.com/x/log.txt?x=14f19dc8a00000
dashboard link: https://syzkaller.appspot.com/bug?extid=77a6e06ea923e1eebe81
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=13baf874a00000

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+77a6e0...@syzkaller.appspotmail.com

[ 36.0729359] panic: lock error: Mutex: mutex_vector_exit,761: assertion
failed: MUTEX_OWNER(mtx->mtx_owner) == curthread: lock 0xffffc60012f72840
cpu 1 lwp 0xffffc60012fea1c0
[ 36.0929623] cpu1: Begin traceback...
[ 36.0929623] vpanic() at netbsd:vpanic+0x214
[ 36.1029793] snprintf() at netbsd:snprintf
[ 36.1129928] lockdebug_abort() at netbsd:lockdebug_abort+0x153
[ 36.1230065] mutex_vector_exit() at netbsd:mutex_vector_exit+0x1bc
[ 36.1330193] do_sys_accept() at netbsd:do_sys_accept+0x346
[ 36.1430379] sys_accept() at netbsd:sys_accept+0xac
[ 36.1530480] sys___syscall() at netbsd:sys___syscall+0xe2
[ 36.1730778] syscall() at netbsd:syscall+0x348
[ 36.1730778] --- syscall (number 198) ---
[ 36.1830888] 77be1803f4aa:
[ 36.1830888] cpu1: End traceback...

[ 36.1830888] dumping to dev 4,1 (offset=0, size=0): not possible
[ 36.1931003] rebooting...

SeaBIOS (version 1.8.2-20190308_060531-google)
Total RAM Size = 0x00000001e0000000 = 7680 MiB
CPUs found: 2 Max CPUs supported: 2
found virtio-scsi at 0:3
virtio-scsi vendor='Google' product='PersistentDisk' rev='1' type=0
removable=0
virtio-scsi blksize=512 sectors=4194304 = 2048 MiB
drive 0x000f29d0: PCHS=0/0/0 translation=lba LCHS=520/128/63 s=4194304
Booting from Hard Disk 0...

>> NetBSD/x86 BIOS Boot, Revision 5.10 (Tue Jul 17 14:59:51 UTC 2018) (from
>> NetBSD 8.0)
>> Memory: 639/3144640 k

1. Boot normally
2. Boot single user
3. Disable ACPI
4. Disable ACPI and SMP
5. Drop to boot prompt

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