uvm_fault(0xffffffff83a4ed18, 0xffff800027922004, 0, 1) -> d
kernel: page fault trap, code=0
Stopped at      ufs_readdir+0x26e:      movzwl  0x4(%r14),%ebx
    TID    PID    UID     PRFLAGS     PFLAGS  CPU  COMMAND
*178150  83880      0         0x2          0    0  syz-executor
ufs_readdir(ffff80002a791430) at ufs_readdir+0x26e sys/ufs/ufs/ufs_vnops.c:1397
VOP_READDIR(fffff2806b7b0eb0,ffff80002a7914b8,fffff28007ffd5b0,ffff80002a7914fc) at VOP_READDIR+0x125 sys/kern/vfs_vops.c:453
sys_getdents(ffff80002f0aaa90,ffff80002a791640,ffff80002a791590) at sys_getdents+0x2dd sys/kern/vfs_syscalls.c:3132
syscall(ffff80002a791640) at syscall+0x962 mi_syscall sys/sys/syscall_mi.h:-1 [inline]
syscall(ffff80002a791640) at syscall+0x962 sys/arch/amd64/amd64/trap.c:783
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x7c81cb4eb630, count: 10
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> 
ddb> set $lines = 0
ddb> set $maxwidth = 0
ddb> show panic
*cpu0: uvm_fault(0xffffffff83a4ed18, 0xffff800027922004, 0, 1) -> d
ddb> trace
ufs_readdir(ffff80002a791430) at ufs_readdir+0x26e sys/ufs/ufs/ufs_vnops.c:1397
VOP_READDIR(fffff2806b7b0eb0,ffff80002a7914b8,fffff28007ffd5b0,ffff80002a7914fc) at VOP_READDIR+0x125 sys/kern/vfs_vops.c:453
sys_getdents(ffff80002f0aaa90,ffff80002a791640,ffff80002a791590) at sys_getdents+0x2dd sys/kern/vfs_syscalls.c:3132
syscall(ffff80002a791640) at syscall+0x962 mi_syscall sys/sys/syscall_mi.h:-1 [inline]
syscall(ffff80002a791640) at syscall+0x962 sys/arch/amd64/amd64/trap.c:783
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x7c81cb4eb630, count: -5
ddb> show registers
rdi                            0x200
rsi                            0x800
rbp               0xffff80002a791420
rbx                            0x200
rdx                                0
rcx               0xfffff2806b87c8d0
rax               0xffff800027922200
r8                0xffffffffffffffff
r9                               0x2
r10               0x4b3bcdd5c6bdb9e2
r11               0x4fa59f5655c57117
r12                                0
r13               0xffff80002a7914b8
r14               0xffff800027922000
r15               0xffff800027922008
rip               0xffffffff811dde4e    ufs_readdir+0x26e
cs                               0x8
rflags                       0x10283    __ALIGN_SIZE+0xf283
rsp               0xffff80002a791270
ss                              0x10
ufs_readdir+0x26e:      movzwl  0x4(%r14),%ebx
ddb>