syzbot

uvm_fault(0xfffffd806e8c73e0, 0x0, 0, 1) -> e
kernel: page fault trap, code=0
Stopped at      dt_ioctl_record_stop+0x108:     movq    0(%r14),%r14
    TID    PID    UID     PRFLAGS     PFLAGS  CPU  COMMAND
*216029  50751      0           0  0x4000000    0K syz-executor
dt_ioctl_record_stop(ffff80000168f000) at dt_ioctl_record_stop+0x108 sys/dev/dt/dt_dev.c:593
dtclose(11e5f,1,2000,ffff8000fffe9a10) at dtclose+0x109 dt_pcb_purge sys/dev/dt/dt_dev.c:-1 [inline]
dtclose(11e5f,1,2000,ffff8000fffe9a10) at dtclose+0x109 sys/dev/dt/dt_dev.c:239
spec_close(ffff80002a2a2740) at spec_close+0x466 sys/kern/spec_vnops.c:-1
VOP_CLOSE(fffffd80601246f0,1,fffffd80097fd1a0,ffff8000fffe9a10) at VOP_CLOSE+0x132 sys/kern/vfs_vops.c:156
vn_closefile(fffffd806d253618,ffff8000fffe9a10) at vn_closefile+0x12b vn_close sys/kern/vfs_vnops.c:298 [inline]
vn_closefile(fffffd806d253618,ffff8000fffe9a10) at vn_closefile+0x12b sys/kern/vfs_vnops.c:621
fdrop(fffffd806d253618,ffff8000fffe9a10) at fdrop+0x121 sys/kern/kern_descrip.c:1281
closef(fffffd806d253618,ffff8000fffe9a10) at closef+0x192 sys/kern/kern_descrip.c:1265
sys_closefrom(ffff8000fffe9a10,ffff80002a2a2a10,ffff80002a2a2960) at sys_closefrom+0x13c sys/kern/kern_descrip.c:1471
syscall(ffff80002a2a2a10) at syscall+0xbd4 mi_syscall sys/sys/syscall_mi.h:176 [inline]
syscall(ffff80002a2a2a10) at syscall+0xbd4 sys/arch/amd64/amd64/trap.c:783
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0xa225852c410, count: 5
https://www.openbsd.org/ddb.html describes the minimum info required in bug
reports.  Insufficient info makes it difficult to find and fix bugs.
ddb{0}> 
ddb{0}> set $lines = 0
ddb{0}> set $maxwidth = 0
ddb{0}> show panic
*cpu0: uvm_fault(0xfffffd806e8c73e0, 0x0, 0, 1) -> e
ddb{0}> trace
dt_ioctl_record_stop(ffff80000168f000) at dt_ioctl_record_stop+0x108 sys/dev/dt/dt_dev.c:593
dtclose(11e5f,1,2000,ffff8000fffe9a10) at dtclose+0x109 dt_pcb_purge sys/dev/dt/dt_dev.c:-1 [inline]
dtclose(11e5f,1,2000,ffff8000fffe9a10) at dtclose+0x109 sys/dev/dt/dt_dev.c:239
spec_close(ffff80002a2a2740) at spec_close+0x466 sys/kern/spec_vnops.c:-1
VOP_CLOSE(fffffd80601246f0,1,fffffd80097fd1a0,ffff8000fffe9a10) at VOP_CLOSE+0x132 sys/kern/vfs_vops.c:156
vn_closefile(fffffd806d253618,ffff8000fffe9a10) at vn_closefile+0x12b vn_close sys/kern/vfs_vnops.c:298 [inline]
vn_closefile(fffffd806d253618,ffff8000fffe9a10) at vn_closefile+0x12b sys/kern/vfs_vnops.c:621
fdrop(fffffd806d253618,ffff8000fffe9a10) at fdrop+0x121 sys/kern/kern_descrip.c:1281
closef(fffffd806d253618,ffff8000fffe9a10) at closef+0x192 sys/kern/kern_descrip.c:1265
sys_closefrom(ffff8000fffe9a10,ffff80002a2a2a10,ffff80002a2a2960) at sys_closefrom+0x13c sys/kern/kern_descrip.c:1471
syscall(ffff80002a2a2a10) at syscall+0xbd4 mi_syscall sys/sys/syscall_mi.h:176 [inline]
syscall(ffff80002a2a2a10) at syscall+0xbd4 sys/arch/amd64/amd64/trap.c:783
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0xa225852c410, count: -10
ddb{0}> show registers
rdi                                0
rsi                                0
rbp               0xffff80002a2a2670
rbx                              0x1
rdx                                0
rcx               0xffff8000fffe9a10
rax               0xffffffff8386e578    dt_prov_syscall
r8                0xffffffff8154f380    uvm_map_inentry_sp
r9                               0x1
r10               0x2749a48ad6e46eff
r11               0x152b2b720ef4f1c5
r12                                0
r13                                0
r14                                0
r15               0xffff800000c4a500
rip               0xffffffff810c5058    dt_ioctl_record_stop+0x108
cs                               0x8
rflags                       0x10207    __ALIGN_SIZE+0xf207
rsp               0xffff80002a2a2640
ss                              0x10
dt_ioctl_record_stop+0x108:     movq    0(%r14),%r14
ddb{0}>