assert "kd_lookup(kd->kd_unit) == NULL" failed in kcov.c (3)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 6405849dc70d add missing MODPY_PYBUILD backends
git tree: openbsd
console output: https://syzkaller.appspot.com/x/log.txt?x=126aeaf4580000
kernel config: https://syzkaller.appspot.com/x/.config?x=1bc15e68cd2a49e5
dashboard link: https://syzkaller.appspot.com/bug?extid=6e940980f272835ed130

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/8e25f3f9cc5c/disk-6405849d.raw.xz
bsd.gdb: https://storage.googleapis.com/syzbot-assets/ac2762cf0c9c/bsd-6405849d.gdb.xz
kernel image: https://storage.googleapis.com/syzbot-assets/a1eef4d5cbf6/kernel-6405849d.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+6e9409...@syzkaller.appspotmail.com

panic: kernel diagnostic assertion "kd_lookup(kd->kd_unit) == NULL" failed: file "/syzkaller/managers/main/kernel/sys/dev/kcov.c", line 306
Starting stack trace...
panic(ffffffff8342a0a6) at panic+0x1ba sys/kern/subr_prf.c:229
__assert(ffffffff833d460e,ffffffff8335d2b6,132,ffffffff833b3f12) at __assert+0x29 sys/kern/subr_prf.c:-1
kcovopen(113d4,1,2000,ffff80002a7f14a0) at kcovopen+0x14f kd_lookup sys/dev/kcov.c:478 [inline]
kcovopen(113d4,1,2000,ffff80002a7f14a0) at kcovopen+0x14f sys/dev/kcov.c:306
spec_open_clone(ffff800031507638) at spec_open_clone+0x287 sys/kern/spec_vnops.c:722
spec_open(ffff800031507638) at spec_open+0x326 sys/kern/spec_vnops.c:148
VOP_OPEN(fffffd8066eb4480,1,fffffd807f7d7820,ffff80002a7f14a0) at VOP_OPEN+0x82 sys/kern/vfs_vops.c:138
vn_open(ffff800031507888,1,0) at vn_open+0x708 sys/kern/vfs_vnops.c:177
doopenat(ffff80002a7f14a0,ffffff9c,200000000000,0,0,ffff800031507a30) at doopenat+0x31d sys/kern/vfs_syscalls.c:1137
syscall(ffff800031507ae0) at syscall+0x97e mi_syscall sys/sys/syscall_mi.h:-1 [inline]
syscall(ffff800031507ae0) at syscall+0x97e sys/arch/amd64/amd64/trap.c:579
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0xbf83c06e4b0, count: 247
End of stack trace.


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[syzbot]

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