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(ffffffff83405dd0) at panic+0x1ba sys/kern/subr_prf.c:229 __assert(ffffffff833b3398,ffffffff8333bf47,132,ffffffff83393530) at __assert+0x29 kcovopen(113d4,e2,2000,ffff80002a802540) at kcovopen+0x14f kd_lookup sys/dev/kcov.c:478 [inline] kcovopen(113d4,e2,2000,ffff80002a802540) at kcovopen+0x14f sys/dev/kcov.c:306 spec_open_clone(ffff80002a7d0e98) at spec_open_clone+0x287 sys/kern/spec_vnops.c:722 spec_open(ffff80002a7d0e98) at spec_open+0x326 sys/kern/spec_vnops.c:148 VOP_OPEN(fffffd806a3160f8,e2,fffffd807f7d7958,ffff80002a802540) at VOP_OPEN+0x82 sys/kern/vfs_vops.c:138 vn_open(ffff80002a7d10e8,2e2,0) at vn_open+0x708 sys/kern/vfs_vnops.c:177 doopenat(ffff80002a802540,ffffff9c,4000000001c0,2e1,0,ffff80002a7d1290) at doopenat+0x31d sys/kern/vfs_syscalls.c:1124 syscall(ffff80002a7d1340) at syscall+0x97e sys/arch/amd64/amd64/trap.c:577 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x3a4d439df90, count: 247 End of stack trace.