login: uvm_fault(0xffffffff83ae0888, 0xffff800029a82000, 0, 2) -> d
kernel: page fault trap, code=2
Stopped at      memset+0x52:    repe stosq      %es:(%rdi)
    TID    PID    UID     PRFLAGS     PFLAGS  CPU  COMMAND
*329804  55097      0      0x1004          0    0  syz-executor
memset() at memset+0x52
ffs_write(ffff80003c914520) at ffs_write+0x4f9 sys/ufs/ffs/ffs_vnops.c:345
VOP_WRITE(ffffef0077545e88,ffff80003c9145b0,0,ffffef0007ffd750) at VOP_WRITE+0x101 sys/kern/vfs_vops.c:245
uvn_io(ffffef006f470328,ffff80003c914730,e,39,1) at uvn_io+0x485 sys/uvm/uvm_vnode.c:1232
uvm_pager_put(ffffef006f470328,ffffef0007245b00,ffff80003c9147d0,ffff80003c9147f4,39,0,a760904e65f71841) at uvm_pager_put+0x10a sys/uvm/uvm_pager.c:505
uvn_flush(ffffef006f470328,0,0,19) at uvn_flush+0x68d sys/uvm/uvm_vnode.c:705
uvn_detach(ffffef006f470328) at uvn_detach+0xb8 sys/uvm/uvm_vnode.c:344
uvm_unmap_detach(ffff80003c914918,0) at uvm_unmap_detach+0x15e sys/uvm/uvm_map.c:1370
uvmspace_exec(ffff80003c8fa550,1000,7f7fffffc000) at uvmspace_exec+0x451 sys/uvm/uvm_map.c:3404
sys_execve(ffff80003c8fa550,ffff80003c914fa0,ffff80003c914ef0) at sys_execve+0xc61 sys/kern/kern_exec.c:474
syscall(ffff80003c914fa0) at syscall+0x962 mi_syscall sys/sys/syscall_mi.h:-1 [inline]
syscall(ffff80003c914fa0) at syscall+0x962 sys/arch/amd64/amd64/trap.c:783
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x7f691db5fb80, 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(0xffffffff83ae0888, 0xffff800029a82000, 0, 2) -> d
ddb> trace
memset() at memset+0x52
ffs_write(ffff80003c914520) at ffs_write+0x4f9 sys/ufs/ffs/ffs_vnops.c:345
VOP_WRITE(ffffef0077545e88,ffff80003c9145b0,0,ffffef0007ffd750) at VOP_WRITE+0x101 sys/kern/vfs_vops.c:245
uvn_io(ffffef006f470328,ffff80003c914730,e,39,1) at uvn_io+0x485 sys/uvm/uvm_vnode.c:1232
uvm_pager_put(ffffef006f470328,ffffef0007245b00,ffff80003c9147d0,ffff80003c9147f4,39,0,a760904e65f71841) at uvm_pager_put+0x10a sys/uvm/uvm_pager.c:505
uvn_flush(ffffef006f470328,0,0,19) at uvn_flush+0x68d sys/uvm/uvm_vnode.c:705
uvn_detach(ffffef006f470328) at uvn_detach+0xb8 sys/uvm/uvm_vnode.c:344
uvm_unmap_detach(ffff80003c914918,0) at uvm_unmap_detach+0x15e sys/uvm/uvm_map.c:1370
uvmspace_exec(ffff80003c8fa550,1000,7f7fffffc000) at uvmspace_exec+0x451 sys/uvm/uvm_map.c:3404
sys_execve(ffff80003c8fa550,ffff80003c914fa0,ffff80003c914ef0) at sys_execve+0xc61 sys/kern/kern_exec.c:474
syscall(ffff80003c914fa0) at syscall+0x962 mi_syscall sys/sys/syscall_mi.h:-1 [inline]
syscall(ffff80003c914fa0) at syscall+0x962 sys/arch/amd64/amd64/trap.c:783
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x7f691db5fb80, count: -12
ddb> show registers
rdi               0xffff800029a82000
rsi                                0
rbp               0xffff80003c914440
rbx               0xffffef006cf83600
rdx                                0
rcx                            0x800
rax                                0
r8                            0x4000    __ALIGN_SIZE+0x3000
r9                                 0
r10               0xe807a7ba7a83e780
r11               0xffff800029a82000
r12                              0x1
r13               0xffff800000c47800
r14               0xffffef006c535d58
r15                          0x79c88    acpi_pdirpa+0x65af9
rip               0xffffffff82f855a2    memset+0x52
cs                               0x8
rflags                       0x10206    __ALIGN_SIZE+0xf206
rsp               0xffff80003c9142c8
ss                              0x10
memset+0x52:    repe stosq      %es:(%rdi)
ddb> show proc
PROC (syz-executor) tid=329804 pid=55097 tcnt=1 stat=onproc
    flags process=1004<INEXEC,SINGLEEXIT> proc=0
    runpri=86, usrpri=86, slppri=32, nice=20
    wchan=0x0, wmesg=, ps_single=0xffff80003c8fa550 scnt=0 ecnt=0
    forw=0xffffffffffffffff, list=0xffff80003c8fba10,0xffffffff839a04e8
    process=0xffff8000ffff9b18 user=0xffff80003c910000, vmspace=0xffffef007766c2e8
    estcpu=36, cpticks=3, pctcpu=0.0, user=0, sys=3, intr=0
ddb>