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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: 74d, last: 29d
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 181d 212d 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 410d 447d 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 302d 302d 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(ffffffff8339a25d) at panic+0x1d0 sys/kern/subr_prf.c:229
__assert(ffffffff833db851,ffffffff833dded3,132,ffffffff834429ad) at __assert+0x29 sys/kern/subr_prf.c:-1
kcovopen(113d4,102,2000,ffff80002a295a08) at kcovopen+0x14f kd_lookup sys/dev/kcov.c:478 [inline]
kcovopen(113d4,102,2000,ffff80002a295a08) at kcovopen+0x14f sys/dev/kcov.c:306
spec_open_clone(ffff80003c473498) at spec_open_clone+0x277 sys/kern/spec_vnops.c:722
spec_open(ffff80003c473498) at spec_open+0x319 sys/kern/spec_vnops.c:148
VOP_OPEN(fffffd805cb22950,102,fffffd80097fb618,ffff80002a295a08) at VOP_OPEN+0x8b sys/kern/vfs_vops.c:138
vn_open(ffff80003c473640,102,0) at vn_open+0x6a0 sys/kern/vfs_vnops.c:177
sys_ktrace(ffff80002a295a08,ffff80003c473820,ffff80003c473770) at sys_ktrace+0x9a sys/kern/kern_ktrace.c:551
syscall(ffff80003c473820) at syscall+0xb17 mi_syscall sys/sys/syscall_mi.h:176 [inline]
syscall(ffff80003c473820) at syscall+0xb17 sys/arch/amd64/amd64/trap.c:765
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0xb3cd99df1e0, count: 247
End of stack trace.
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Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
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.