login: uvm_fault(0xffffffff83a51d30, 0xffff8000295a2068, 0, 1) -> d
kernel: page fault trap, code=0
Stopped at      ffs2_balloc+0xa0d:      movq    0(%rcx,%rax,8),%r14
    TID    PID    UID     PRFLAGS     PFLAGS  CPU  COMMAND
 226815  93851      0         0x2        0x1    0  syz-executor
*348264  63120      0         0x2        0x1    1K syz-executor
ffs2_balloc(fffffd806c684bb0,65477,50,fffffd80097fd340,1,ffff80002a304638) at ffs2_balloc+0xa0d sys/ufs/ffs/ffs_balloc.c:614
ffs_write(ffff80002a3046c0) at ffs_write+0x4f9 sys/ufs/ffs/ffs_vnops.c:345
VOP_WRITE(fffffd805f415a80,ffff80002a304770,3,fffffd80097fd340) at VOP_WRITE+0x101 sys/kern/vfs_vops.c:245
ktrwriteraw(ffff80002a243c98,fffffd805f415a80,fffffd80097fd340,ffff80002a304840,ffff80002a304820) at ktrwriteraw+0x1be sys/kern/kern_ktrace.c:691
ktrsysret(ffff80002a243c98,5b,0,ffff80002a304910) at ktrsysret+0x192 ktrwrite2 sys/kern/kern_ktrace.c:-1 [inline]
ktrsysret(ffff80002a243c98,5b,0,ffff80002a304910) at ktrsysret+0x192 sys/kern/kern_ktrace.c:209
syscall(ffff80002a3049c0) at syscall+0xa51 mi_syscall_return sys/sys/syscall_mi.h:204 [inline]
syscall(ffff80002a3049c0) at syscall+0xa51 sys/arch/amd64/amd64/trap.c:804
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x72a10126c1d0, count: 8
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{1}> 
ddb{1}> set $lines = 0
ddb{1}> set $maxwidth = 0
ddb{1}> show panic
*cpu1: uvm_fault(0xffffffff83a51d30, 0xffff8000295a2068, 0, 1) -> d
ddb{1}> trace
ffs2_balloc(fffffd806c684bb0,65477,50,fffffd80097fd340,1,ffff80002a304638) at ffs2_balloc+0xa0d sys/ufs/ffs/ffs_balloc.c:614
ffs_write(ffff80002a3046c0) at ffs_write+0x4f9 sys/ufs/ffs/ffs_vnops.c:345
VOP_WRITE(fffffd805f415a80,ffff80002a304770,3,fffffd80097fd340) at VOP_WRITE+0x101 sys/kern/vfs_vops.c:245
ktrwriteraw(ffff80002a243c98,fffffd805f415a80,fffffd80097fd340,ffff80002a304840,ffff80002a304820) at ktrwriteraw+0x1be sys/kern/kern_ktrace.c:691
ktrsysret(ffff80002a243c98,5b,0,ffff80002a304910) at ktrsysret+0x192 ktrwrite2 sys/kern/kern_ktrace.c:-1 [inline]
ktrsysret(ffff80002a243c98,5b,0,ffff80002a304910) at ktrsysret+0x192 sys/kern/kern_ktrace.c:209
syscall(ffff80002a3049c0) at syscall+0xa51 mi_syscall_return sys/sys/syscall_mi.h:204 [inline]
syscall(ffff80002a3049c0) at syscall+0xa51 sys/arch/amd64/amd64/trap.c:804
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x72a10126c1d0, count: -7
ddb{1}> show registers
rdi                                0
rsi                                0
rbp               0xffff80002a3045e0
rbx                                0
rdx                                0
rcx               0xffff8000295a2000
rax                              0xd
r8                0xffffffffffffffff
r9                0xffff80002a304638
r10               0xa8ed3516a86e10e4
r11               0xce4e709bf31f2ee1
r12                              0x1
r13               0xffff800000c31800
r14               0xffff80002a304470
r15               0xfffffd805d515e40
rip               0xffffffff82b2dfbd    ffs2_balloc+0xa0d
cs                               0x8
rflags                       0x10246    __ALIGN_SIZE+0xf246
rsp               0xffff80002a304460
ss                              0x10
ffs2_balloc+0xa0d:      movq    0(%rcx,%rax,8),%r14
ddb{1}> show proc
PROC (syz-executor) tid=348264 pid=63120 tcnt=1 stat=onproc
    flags process=2<EXEC> proc=1<INKTR>
    runpri=32, usrpri=86, slppri=32, nice=20
    wchan=0x0, wmesg=, ps_single=0x0 scnt=0 ecnt=0
    forw=0xffffffffffffffff, list=0xffff80002a242d08,0xffff80002a2427e8
    process=0xffff8000ffff5348 user=0xffff80002a2ff000, vmspace=0xfffffd800b063d58
    estcpu=36, cpticks=26, pctcpu=0.3, user=2, sys=23, intr=1
ddb{1}>