uvm_fault(0xffffffff836190a8, 0xffff800027c92030, 0, 1) -> d
kernel: page fault trap, code=0
Stopped at      ffs2_balloc+0x9fe:      movq    0(%rcx,%rax,8),%r14
    TID    PID    UID     PRFLAGS     PFLAGS  CPU  COMMAND
  28508  19191      0           0  0x4000000    0  syz-executor
*323063  52352     73   0x1100010          0    1K syslogd
ffs2_balloc(fffffd806e4e4228,4ad4c,68,fffffd807f7d3bc8,1,ffff80002a068478) at ffs2_balloc+0x9fe sys/ufs/ffs/ffs_balloc.c:614
ffs_write(ffff80002a068500) at ffs_write+0x4f9 sys/ufs/ffs/ffs_vnops.c:345
VOP_WRITE(fffffd806e29d998,ffff80002a068720,3,fffffd807f7d3bc8) at VOP_WRITE+0x102 sys/kern/vfs_vops.c:245
vn_write(fffffd806f8a4558,ffff80002a068720,0) at vn_write+0x1d1 sys/kern/vfs_vnops.c:408
dofilewritev(ffff8000ffffd6d8,e,ffff80002a068720,0,ffff80002a0687e0) at dofilewritev+0x23c sys/kern/sys_generic.c:380
sys_writev(ffff8000ffffd6d8,ffff80002a068890,ffff80002a0687e0) at sys_writev+0xd8 sys/kern/sys_generic.c:327
syscall(ffff80002a068890) at syscall+0xbb6 mi_syscall sys/sys/syscall_mi.h:179 [inline]
syscall(ffff80002a068890) at syscall+0xbb6 sys/arch/amd64/amd64/trap.c:577
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x7d175ecb0a30, count: 7
https://www.openbsd.org/ddb.html describes the minimum info required in bug
reports.  Insufficient info makes it difficult to find and fix bugs.