witness: thread exiting with locks held (3)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: b57dcb7bc7e3 use .Lb for libi386 and libamd64; OK guenther..
git tree: openbsd
console output: https://syzkaller.appspot.com/x/log.txt?x=13084c0c580000
kernel config: https://syzkaller.appspot.com/x/.config?x=7058272de1526588
dashboard link: https://syzkaller.appspot.com/bug?extid=054f43016b494604339c

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/ebd75927209f/disk-b57dcb7b.raw.xz
bsd.gdb: https://storage.googleapis.com/syzbot-assets/c8ad6a2fdd9b/bsd-b57dcb7b.gdb.xz
kernel image: https://storage.googleapis.com/syzbot-assets/fd4c4e2649c8/kernel-b57dcb7b.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+054f43...@syzkaller.appspotmail.com

witness: thread 0xffff80002a3a6558 exiting with the following locks held:
shared rwlock netlock r = 0 (0xffffffff83867110)
#0 witness_lock+0x5bb stacktrace_save sys/sys/stacktrace.h:37 [inline]
#0 witness_lock+0x5bb sys/kern/subr_witness.c:1160
#1 rw_do_enter_read+0x36e sys/kern/kern_rwlock.c:397
#2 sysctl_file+0xb13 sys/kern/kern_sysctl.c:1767
#3 kern_sysctl+0x251 sys/kern/kern_sysctl.c:526
#4 sys_sysctl+0x3f2 sys/kern/kern_sysctl.c:-1
#5 syscall+0xbc6 mi_syscall sys/sys/syscall_mi.h:176 [inline]
#5 syscall+0xbc6 sys/arch/amd64/amd64/trap.c:579
#6 Xsyscall+0x128
panic: thread 0xffff80002a3a6558 cannot exit while holding sleeplocks
Starting stack trace...
panic(ffffffff83356683) at panic+0x1d0 sys/kern/subr_prf.c:229
witness_thread_exit(ffff80002a3a6558) at witness_thread_exit+0x426 sys/kern/subr_witness.c:1408
reaper(ffff8000ffffd1f8) at reaper+0x1ba sys/kern/kern_exit.c:492
end trace frame: 0x0, count: 254
End of stack trace.


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