uvm_fault(0xffffffff839ce170, 0xffff800024522004, 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
*141119   5621      0         0x2          0    0  syz-executor
ufs_readdir(ffff80002a835950) at ufs_readdir+0x26e sys/ufs/ufs/ufs_vnops.c:1397
VOP_READDIR(fffffd807d28ddd0,ffff80002a8359d8,fffffd8007ffd958,ffff80002a835a1c) at VOP_READDIR+0x125 sys/kern/vfs_vops.c:453
sys_getdents(ffff80003acfafb0,ffff80002a835b60,ffff80002a835ab0) at sys_getdents+0x2dd sys/kern/vfs_syscalls.c:3219
syscall(ffff80002a835b60) at syscall+0x962 mi_syscall sys/sys/syscall_mi.h:-1 [inline]
syscall(ffff80002a835b60) at syscall+0x962 sys/arch/amd64/amd64/trap.c:783
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x7e256b7144a0, 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(0xffffffff839ce170, 0xffff800024522004, 0, 1) -> d
ddb> trace
ufs_readdir(ffff80002a835950) at ufs_readdir+0x26e sys/ufs/ufs/ufs_vnops.c:1397
VOP_READDIR(fffffd807d28ddd0,ffff80002a8359d8,fffffd8007ffd958,ffff80002a835a1c) at VOP_READDIR+0x125 sys/kern/vfs_vops.c:453
sys_getdents(ffff80003acfafb0,ffff80002a835b60,ffff80002a835ab0) at sys_getdents+0x2dd sys/kern/vfs_syscalls.c:3219
syscall(ffff80002a835b60) at syscall+0x962 mi_syscall sys/sys/syscall_mi.h:-1 [inline]
syscall(ffff80002a835b60) at syscall+0x962 sys/arch/amd64/amd64/trap.c:783
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x7e256b7144a0, count: -5
ddb>