uvm_fault(0xffffffff839dd7a8, 0xffff800029e02068, 0, 1) -> d
kernel: page fault trap, code=0
Stopped at      ffs2_balloc+0xa0a:      movq    0(%rcx,%rax,8),%r14
    TID    PID    UID     PRFLAGS     PFLAGS  CPU  COMMAND
*147380  32560      0         0x2        0x1    0  syz-executor
ffs2_balloc(fffff5806cd75300,66cc0,50,fffff58007ffd5b0,1,ffff80002a886ed8) at ffs2_balloc+0xa0a sys/ufs/ffs/ffs_balloc.c:614
ffs_write(ffff80002a886f60) at ffs_write+0x4f9 sys/ufs/ffs/ffs_vnops.c:345
VOP_WRITE(fffff58070eb7620,ffff80002a887010,3,fffff58007ffd5b0) at VOP_WRITE+0x101 sys/kern/vfs_vops.c:245
ktrwriteraw(ffff80002a7367d0,fffff58070eb7620,fffff58007ffd5b0,ffff80002a8870e0,ffff80002a8870c0) at ktrwriteraw+0x19b sys/kern/kern_ktrace.c:692
ktrsysret(ffff80002a7367d0,5b,0,ffff80002a8871a0) at ktrsysret+0x17f ktrwrite2 sys/kern/kern_ktrace.c:-1 [inline]
ktrsysret(ffff80002a7367d0,5b,0,ffff80002a8871a0) at ktrsysret+0x17f sys/kern/kern_ktrace.c:209
syscall(ffff80002a887250) at syscall+0xad9 mi_syscall_return sys/sys/syscall_mi.h:204 [inline]
syscall(ffff80002a887250) at syscall+0xad9 sys/arch/amd64/amd64/trap.c:804
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x74abb397fde0, 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> 
ddb> set $lines = 0
ddb> set $maxwidth = 0
ddb> show panic
*cpu0: uvm_fault(0xffffffff839dd7a8, 0xffff800029e02068, 0, 1) -> d
ddb> trace
ffs2_balloc(fffff5806cd75300,66cc0,50,fffff58007ffd5b0,1,ffff80002a886ed8) at ffs2_balloc+0xa0a sys/ufs/ffs/ffs_balloc.c:614
ffs_write(ffff80002a886f60) at ffs_write+0x4f9 sys/ufs/ffs/ffs_vnops.c:345
VOP_WRITE(fffff58070eb7620,ffff80002a887010,3,fffff58007ffd5b0) at VOP_WRITE+0x101 sys/kern/vfs_vops.c:245
ktrwriteraw(ffff80002a7367d0,fffff58070eb7620,fffff58007ffd5b0,ffff80002a8870e0,ffff80002a8870c0) at ktrwriteraw+0x19b sys/kern/kern_ktrace.c:692
ktrsysret(ffff80002a7367d0,5b,0,ffff80002a8871a0) at ktrsysret+0x17f ktrwrite2 sys/kern/kern_ktrace.c:-1 [inline]
ktrsysret(ffff80002a7367d0,5b,0,ffff80002a8871a0) at ktrsysret+0x17f sys/kern/kern_ktrace.c:209
syscall(ffff80002a887250) at syscall+0xad9 mi_syscall_return sys/sys/syscall_mi.h:204 [inline]
syscall(ffff80002a887250) at syscall+0xad9 sys/arch/amd64/amd64/trap.c:804
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x74abb397fde0, count: -7
ddb>