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.