uvm_fault(0xffffffff83abc5a8, 0xffff800019922018, 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
*212285  34632      0      0x1004          0    0  syz-executor
ffs2_balloc(fffff4806d673c00,3f000,1000,fffff48007ffd618,1,ffff80002a795418) at ffs2_balloc+0xa0a sys/ufs/ffs/ffs_balloc.c:614
ffs_write(ffff80002a7954a0) at ffs_write+0x4f9 sys/ufs/ffs/ffs_vnops.c:345
VOP_WRITE(fffff4806d5c22c0,ffff80002a795530,0,fffff48007ffd618) at VOP_WRITE+0x101 sys/kern/vfs_vops.c:245
uvn_io(fffff4806fbfd8c8,ffff80002a7956b0,1,39,1) at uvn_io+0x485 sys/uvm/uvm_vnode.c:1232
uvm_pager_put(fffff4806fbfd8c8,fffff48007344c80,ffff80002a795750,ffff80002a795774,39,0,949d40b4ca004875) at uvm_pager_put+0x10a sys/uvm/uvm_pager.c:531
uvn_flush(fffff4806fbfd8c8,0,0,19) at uvn_flush+0x68d sys/uvm/uvm_vnode.c:705
uvn_detach(fffff4806fbfd8c8) at uvn_detach+0xb8 sys/uvm/uvm_vnode.c:344
uvm_unmap_detach(ffff80002a795898,0) at uvm_unmap_detach+0x15e sys/uvm/uvm_map.c:1370
uvmspace_exec(ffff800035cdb4e8,1000,7f7fffffc000) at uvmspace_exec+0x451 sys/uvm/uvm_map.c:3404
sys_execve(ffff800035cdb4e8,ffff80002a795f20,ffff80002a795e70) at sys_execve+0xc61 sys/kern/kern_exec.c:474
syscall(ffff80002a795f20) at syscall+0x962 mi_syscall sys/sys/syscall_mi.h:-1 [inline]
syscall(ffff80002a795f20) at syscall+0x962 sys/arch/amd64/amd64/trap.c:783
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x7a43bbb26ec0, count: 3
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(0xffffffff83abc5a8, 0xffff800019922018, 0, 1) -> d
ddb> show kasan
No such command
ddb> trace
ffs2_balloc(fffff4806d673c00,3f000,1000,fffff48007ffd618,1,ffff80002a795418) at ffs2_balloc+0xa0a sys/ufs/ffs/ffs_balloc.c:614
ffs_write(ffff80002a7954a0) at ffs_write+0x4f9 sys/ufs/ffs/ffs_vnops.c:345
VOP_WRITE(fffff4806d5c22c0,ffff80002a795530,0,fffff48007ffd618) at VOP_WRITE+0x101 sys/kern/vfs_vops.c:245
uvn_io(fffff4806fbfd8c8,ffff80002a7956b0,1,39,1) at uvn_io+0x485 sys/uvm/uvm_vnode.c:1232
uvm_pager_put(fffff4806fbfd8c8,fffff48007344c80,ffff80002a795750,ffff80002a795774,39,0,949d40b4ca004875) at uvm_pager_put+0x10a sys/uvm/uvm_pager.c:531
uvn_flush(fffff4806fbfd8c8,0,0,19) at uvn_flush+0x68d sys/uvm/uvm_vnode.c:705
uvn_detach(fffff4806fbfd8c8) at uvn_detach+0xb8 sys/uvm/uvm_vnode.c:344
uvm_unmap_detach(ffff80002a795898,0) at uvm_unmap_detach+0x15e sys/uvm/uvm_map.c:1370
uvmspace_exec(ffff800035cdb4e8,1000,7f7fffffc000) at uvmspace_exec+0x451 sys/uvm/uvm_map.c:3404
sys_execve(ffff800035cdb4e8,ffff80002a795f20,ffff80002a795e70) at sys_execve+0xc61 sys/kern/kern_exec.c:474
syscall(ffff80002a795f20) at syscall+0x962 mi_syscall sys/sys/syscall_mi.h:-1 [inline]
syscall(ffff80002a795f20) at syscall+0x962 sys/arch/amd64/amd64/trap.c:783
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x7a43bbb26ec0, count: -12
ddb>