syzbot


assert "kd_lookup(kd->kd_unit) == NULL" failed in kcov.c (4)

Status: upstream: reported on 2025/09/29 06:33
Reported-by: syzbot+1d63f7ba102fdffd69f3@syzkaller.appspotmail.com
First crash: 127d, last: 8d10h
Similar bugs (3)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
openbsd assert "kd_lookup(kd->kd_unit) == NULL" failed in kcov.c (3) -1 2 234d 266d 0/3 auto-obsoleted due to no activity on 2025/09/12 14:51
openbsd assert "kd_lookup(kd->kd_unit) == NULL" failed in kcov.c -1 2 463d 501d 0/3 auto-obsoleted due to no activity on 2025/01/26 12:26
openbsd assert "kd_lookup(kd->kd_unit) == NULL" failed in kcov.c (2) -1 1 356d 356d 0/3 auto-obsoleted due to no activity on 2025/05/13 16:49

Sample crash report:
panic: kernel diagnostic assertion "kd_lookup(kd->kd_unit) == NULL" failed: file "/syzkaller/managers/multicore/kernel/sys/dev/kcov.c", line 306
Starting stack trace...
panic(ffffffff833b423c) at panic+0x1d0 sys/kern/subr_prf.c:229
__assert(ffffffff833eeac7,ffffffff833eec13,132,ffffffff8345424c) at __assert+0x29 sys/kern/subr_prf.c:-1
kcovopen(113d4,50f,2000,ffff80003c435780) at kcovopen+0x14f kd_lookup sys/dev/kcov.c:478 [inline]
kcovopen(113d4,50f,2000,ffff80003c435780) at kcovopen+0x14f sys/dev/kcov.c:306
spec_open_clone(ffff80003c4df628) at spec_open_clone+0x277 sys/kern/spec_vnops.c:722
spec_open(ffff80003c4df628) at spec_open+0x319 sys/kern/spec_vnops.c:148
VOP_OPEN(fffffd8061066968,50f,fffffd80097fd548,ffff80003c435780) at VOP_OPEN+0x8b sys/kern/vfs_vops.c:138
vn_open(ffff80003c4df870,70f,0) at vn_open+0x6a0 sys/kern/vfs_vnops.c:177
doopenat(ffff80003c435780,ffffff9c,200000000040,70e,0,ffff80003c4dfa20) at doopenat+0x35b sys/kern/vfs_syscalls.c:1138
syscall(ffff80003c4dfad0) at syscall+0xbd4 mi_syscall sys/sys/syscall_mi.h:176 [inline]
syscall(ffff80003c4dfad0) at syscall+0xbd4 sys/arch/amd64/amd64/trap.c:775
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0xfcb496c3050, count: 247
End of stack trace.
syncing disks...

Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/01/26 16:11 openbsd 4c8dfe351ad4 a4c52dd6 .config console log report [disk image] [bsd.gdb] [kernel image] ci-openbsd-multicore assert "kd_lookup(kd->kd_unit) == NULL" failed in kcov.c
2025/11/13 12:36 openbsd b192115449a5 07e030de .config console log report [disk image] [bsd.gdb] [kernel image] ci-openbsd-multicore assert "kd_lookup(kd->kd_unit) == NULL" failed in kcov.c
2025/09/29 06:33 openbsd 3abf7a093b78 770ff59f .config console log report [disk image] [bsd.gdb] [kernel image] ci-openbsd-main assert "kd_lookup(kd->kd_unit) == NULL" failed in kcov.c
* Struck through repros no longer work on HEAD.