uvm_fault(0xffffffff83a83b10, 0xffff80001bfb2000, 0, 2) -> d kernel: page fault trap, code=2 Stopped at memset+0x52: repe stosq %es:(%rdi) TID PID UID PRFLAGS PFLAGS CPU COMMAND *129079 59833 0 0 0x4000000 0 syz-executor memset() at memset+0x52 VOP_WRITE(fffffd806b1ebb48,ffff80003a4cf848,7,fffffd8007ffd548) at VOP_WRITE+0x101 sys/kern/vfs_vops.c:245 vn_write(fffffd806907d968,ffff80003a4cf848,0) at vn_write+0x1c2 sys/kern/vfs_vnops.c:414 dofilewritev(ffff80002f0b14d8,3,ffff80003a4cf848,0,ffff80003a4cf8f0) at dofilewritev+0x2bd sys/kern/sys_generic.c:384 sys_write(ffff80002f0b14d8,ffff80003a4cf9a0,ffff80003a4cf8f0) at sys_write+0xa2 sys/kern/sys_generic.c:300 syscall(ffff80003a4cf9a0) at syscall+0x962 mi_syscall sys/sys/syscall_mi.h:-1 [inline] syscall(ffff80003a4cf9a0) at syscall+0x962 sys/arch/amd64/amd64/trap.c:783 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x16b99e653f0, 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(0xffffffff83a83b10, 0xffff80001bfb2000, 0, 2) -> d ddb> trace memset() at memset+0x52 VOP_WRITE(fffffd806b1ebb48,ffff80003a4cf848,7,fffffd8007ffd548) at VOP_WRITE+0x101 sys/kern/vfs_vops.c:245 vn_write(fffffd806907d968,ffff80003a4cf848,0) at vn_write+0x1c2 sys/kern/vfs_vnops.c:414 dofilewritev(ffff80002f0b14d8,3,ffff80003a4cf848,0,ffff80003a4cf8f0) at dofilewritev+0x2bd sys/kern/sys_generic.c:384 sys_write(ffff80002f0b14d8,ffff80003a4cf9a0,ffff80003a4cf8f0) at sys_write+0xa2 sys/kern/sys_generic.c:300 syscall(ffff80003a4cf9a0) at syscall+0x962 mi_syscall sys/sys/syscall_mi.h:-1 [inline] syscall(ffff80003a4cf9a0) at syscall+0x962 sys/arch/amd64/amd64/trap.c:783 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x16b99e653f0, count: -7 ddb> show registers rdi 0xffff80001bfb2000 rsi 0 rbp 0xffff80003a4cf680 rbx 0xe rdx 0 rcx 0x800 rax 0 r8 0x4000 __ALIGN_SIZE+0x3000 r9 0 r10 0x3de88e34a1521009 r11 0xffff80001bfb2000 r12 0x4000 __ALIGN_SIZE+0x3000 r13 0x4000 __ALIGN_SIZE+0x3000 r14 0xffff80001bfb2000 r15 0x4000 __ALIGN_SIZE+0x3000 rip 0xffffffff83126222 memset+0x52 cs 0x8 rflags 0x10206 __ALIGN_SIZE+0xf206 rsp 0xffff80003a4cf5b8 ss 0x10 memset+0x52: repe stosq %es:(%rdi) ddb> show proc PROC (syz-executor) tid=129079 pid=59833 tcnt=3 stat=onproc flags process=0 proc=4000000 runpri=74, usrpri=74, slppri=17, nice=20 wchan=0x0, wmesg=, ps_single=0x0 scnt=0 ecnt=0 forw=0xffffffffffffffff, list=0xffff80002f0b07e0,0xffff80002a736d10 process=0xffff8000ffffba98 user=0xffff80003a4ca000, vmspace=0xfffffd806cab7180 estcpu=24, cpticks=0, pctcpu=0.0, user=0, sys=0, intr=0 ddb> ps PID TID PPID UID S FLAGS WAIT COMMAND 26065 127887 68001 0 2 0 syz-executor 26065 218049 68001 0 2 0x4000000 syz-executor 26065 52631 68001 0 2 0x4000000 syz-executor 27478 224909 16957 0 2 0 syz-executor 27478 371568 16957 0 2 0x4000000 syz-executor 27478 334862 16957 0 3 0x4000080 fsleep syz-executor 59014 331424 14557 0 2 0 syz-executor 59014 285945 14557 0 3 0x4000080 fifor syz-executor 59014 440308 14557 0 2 0x4000000 syz-executor 42136 399583 48418 0 3 0x80 nanoslp syz-executor 42136 268672 48418 0 3 0x4000080 sbwait syz-executor 42136 497091 48418 0 3 0x4000080 fsleep syz-executor 59833 102984 67515 0 3 0x80 nanoslp syz-executor *59833 129079 67515 0 7 0x4000000 syz-executor 59833 454671 67515 0 3 0x4000080 fsleep syz-executor 1499 508019 12263 60929 2 0x10 syz-executor 1499 94040 12263 60929 2 0x4000011 syz-executor 1499 378037 12263 60929 3 0x4000090 fsleep syz-executor 33537 450241 99889 0 2 0x1 syz-executor 33537 405380 99889 0 2 0x4000001 syz-executor 33537 166466 99889 0 3 0x4000080 fsleep syz-executor 92719 172649 78723 0 2 0x1 syz-executor 92719 316039 78723 0 2 0x4000001 syz-executor 12104 201701 1 0 3 0x82 nanoslp getty 37722 152325 0 0 3 0x14200 acct acct 68001 348902 72273 0 3 0x82 nanoslp syz-executor 99889 200731 72273 0 3 0x82 nanoslp syz-executor 12263 226168 72273 0 3 0x82 nanoslp syz-executor 67515 194300 72273 0 3 0x82 nanoslp syz-executor 16957 311347 72273 0 3 0x82 nanoslp syz-executor 78723 92619 72273 0 3 0x82 nanoslp syz-executor 48418 473048 72273 0 3 0x82 nanoslp syz-executor 14557 140704 72273 0 3 0x82 nanoslp syz-executor 72273 403298 1 0 3 0x82 kqread syz-executor 24326 97632 1 73 3 0x1100090 kqread syslogd 53098 28636 0 0 3 0x14200 bored smr 69729 186259 0 0 2 0x14200 zerothread 58890 434175 0 0 3 0x14200 aiodoned aiodoned 55744 3295 0 0 3 0x14200 syncer update 88085 158283 0 0 3 0x14200 cleaner cleaner 64141 287717 0 0 3 0x14200 reaper reaper 84080 295508 0 0 3 0x14200 pgdaemon pagedaemon 98328 378303 0 0 3 0x14200 bored viomb 8072 38906 0 0 3 0x40014200 acpi0 acpi0 64387 200730 0 0 3 0x14200 bored softnet0 12367 458371 0 0 3 0x14200 bored systqmp 39866 248717 0 0 3 0x14200 bored systq 43559 242062 0 0 3 0x40014200 tmoslp softclock 98133 254871 0 0 3 0x40014200 idle0 1 234924 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb> show all locks No such command ddb>