panic: kernel diagnostic assertion "kd_lookup(kd->kd_unit) == NULL" failed: file "/syzkaller/managers/main/kernel/sys/dev/kcov.c", line 311 Starting stack trace... panic(ffffffff830b682f) at panic+0x1ba sys/kern/subr_prf.c:229 __assert(ffffffff8306b53c,ffffffff830021d7,137,ffffffff8304f8bf) at __assert+0x29 kcovopen(113d4,1,2000,ffff800036011478) at kcovopen+0x14f kd_lookup sys/dev/kcov.c:483 [inline] kcovopen(113d4,1,2000,ffff800036011478) at kcovopen+0x14f sys/dev/kcov.c:311 spec_open_clone(ffff80002a4eb558) at spec_open_clone+0x287 sys/kern/spec_vnops.c:722 spec_open(ffff80002a4eb558) at spec_open+0x326 sys/kern/spec_vnops.c:148 VOP_OPEN(fffffd806fc90298,1,fffffd807f7d7888,ffff800036011478) at VOP_OPEN+0x82 sys/kern/vfs_vops.c:138 vn_open(ffff80002a4eb7a8,1,0) at vn_open+0x708 sys/kern/vfs_vnops.c:177 doopenat(ffff800036011478,ffffff9c,20000080,0,0,ffff80002a4eb950) at doopenat+0x31d sys/kern/vfs_syscalls.c:1123 syscall(ffff80002a4eba00) at syscall+0x97e sys/arch/amd64/amd64/trap.c:577 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x520195ce20, count: 247 End of stack trace.