syzbot

login: uvm_fault(0xfffffd8064cd9210, 0x0, 0, 1) -> e
fatal page fault in supervisor mode
trap type 6 code 0 rip ffffffff81536ed8 cs 8 rflags 10246 cr2 0 cpl 0 rsp ffff800035c00c50
gsbase 0xffff8000299edff0  kgsbase 0x0
panic: trap type 6, code=0, pc=ffffffff81536ed8
Starting stack trace...
panic(ffffffff833a53ae) at panic+0x1d0 sys/kern/subr_prf.c:229
kerntrap(ffff800035c00ba0) at kerntrap+0x30b
alltraps_kern_meltdown() at alltraps_kern_meltdown+0x7b
dt_ioctl_record_stop(ffff80000147d000) at dt_ioctl_record_stop+0x108 sys/dev/dt/dt_dev.c:586
dtclose(11e5f,81,2000,ffff80003bc34fb8) at dtclose+0x109 dt_pcb_purge sys/dev/dt/dt_dev.c:-1 [inline]
dtclose(11e5f,81,2000,ffff80003bc34fb8) at dtclose+0x109 sys/dev/dt/dt_dev.c:232
spec_close(ffff800035c00d50) at spec_close+0x466 sys/kern/spec_vnops.c:-1
VOP_CLOSE(fffffd8077ce3980,81,fffffd80097fb478,ffff80003bc34fb8) at VOP_CLOSE+0x132 sys/kern/vfs_vops.c:156
vn_closefile(fffffd806b017300,ffff80003bc34fb8) at vn_closefile+0x12b vn_close sys/kern/vfs_vnops.c:292 [inline]
vn_closefile(fffffd806b017300,ffff80003bc34fb8) at vn_closefile+0x12b sys/kern/vfs_vnops.c:615
fdrop(fffffd806b017300,ffff80003bc34fb8) at fdrop+0x121 sys/kern/kern_descrip.c:1267
closef(fffffd806b017300,ffff80003bc34fb8) at closef+0x192 sys/kern/kern_descrip.c:1251
fdfree(ffff80003bc34fb8) at fdfree+0x116 sys/kern/kern_descrip.c:1182
exit1(ffff80003bc34fb8,b,0,1) at exit1+0x576 sys/kern/kern_exit.c:215
sys_exit(ffff80003bc34fb8,ffff800035c010c0,ffff800035c01010) at sys_exit+0x1a sys/kern/kern_exit.c:-1
syscall(ffff800035c010c0) at syscall+0xb17 mi_syscall sys/sys/syscall_mi.h:176 [inline]
syscall(ffff800035c010c0) at syscall+0xb17 sys/arch/amd64/amd64/trap.c:748
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x743df2ef6ed0, count: 242
End of stack trace.