uvm_fault(0xffffffff83a99b28, 0xffff800019a42000, 0, 2) -> d kernel: page fault trap, code=2 Stopped at memset+0x52: repe stosq %es:(%rdi) TID PID UID PRFLAGS PFLAGS CPU COMMAND *464137 25546 0 0x1004 0 0 syz-executor memset() at memset+0x52 ffs_write(ffff80002a79b300) at ffs_write+0x4f9 sys/ufs/ffs/ffs_vnops.c:345 VOP_WRITE(fffff6806e252618,ffff80002a79b390,0,fffff68007ffd680) at VOP_WRITE+0x101 sys/kern/vfs_vops.c:245 uvn_io(fffff6806f19b198,ffff80002a79b510,1,39,1) at uvn_io+0x485 sys/uvm/uvm_vnode.c:1232 uvm_pager_put(fffff6806f19b198,fffff68007312c80,ffff80002a79b5b0,ffff80002a79b5d4,39,0,71f68aec630e16ba) at uvm_pager_put+0x10a sys/uvm/uvm_pager.c:531 uvn_flush(fffff6806f19b198,0,0,19) at uvn_flush+0x68d sys/uvm/uvm_vnode.c:705 uvn_detach(fffff6806f19b198) at uvn_detach+0xb8 sys/uvm/uvm_vnode.c:344 uvm_unmap_detach(ffff80002a79b6f8,0) at uvm_unmap_detach+0x15e sys/uvm/uvm_map.c:1370 uvmspace_exec(ffff80002a77d240,1000,7f7fffffc000) at uvmspace_exec+0x451 sys/uvm/uvm_map.c:3404 sys_execve(ffff80002a77d240,ffff80002a79bd80,ffff80002a79bcd0) at sys_execve+0xc61 sys/kern/kern_exec.c:474 syscall(ffff80002a79bd80) at syscall+0x962 mi_syscall sys/sys/syscall_mi.h:-1 [inline] syscall(ffff80002a79bd80) at syscall+0x962 sys/arch/amd64/amd64/trap.c:783 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7da0aa2d9ca0, 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(0xffffffff83a99b28, 0xffff800019a42000, 0, 2) -> d ddb> show kasan No such command ddb> trace memset() at memset+0x52 ffs_write(ffff80002a79b300) at ffs_write+0x4f9 sys/ufs/ffs/ffs_vnops.c:345 VOP_WRITE(fffff6806e252618,ffff80002a79b390,0,fffff68007ffd680) at VOP_WRITE+0x101 sys/kern/vfs_vops.c:245 uvn_io(fffff6806f19b198,ffff80002a79b510,1,39,1) at uvn_io+0x485 sys/uvm/uvm_vnode.c:1232 uvm_pager_put(fffff6806f19b198,fffff68007312c80,ffff80002a79b5b0,ffff80002a79b5d4,39,0,71f68aec630e16ba) at uvm_pager_put+0x10a sys/uvm/uvm_pager.c:531 uvn_flush(fffff6806f19b198,0,0,19) at uvn_flush+0x68d sys/uvm/uvm_vnode.c:705 uvn_detach(fffff6806f19b198) at uvn_detach+0xb8 sys/uvm/uvm_vnode.c:344 uvm_unmap_detach(ffff80002a79b6f8,0) at uvm_unmap_detach+0x15e sys/uvm/uvm_map.c:1370 uvmspace_exec(ffff80002a77d240,1000,7f7fffffc000) at uvmspace_exec+0x451 sys/uvm/uvm_map.c:3404 sys_execve(ffff80002a77d240,ffff80002a79bd80,ffff80002a79bcd0) at sys_execve+0xc61 sys/kern/kern_exec.c:474 syscall(ffff80002a79bd80) at syscall+0x962 mi_syscall sys/sys/syscall_mi.h:-1 [inline] syscall(ffff80002a79bd80) at syscall+0x962 sys/arch/amd64/amd64/trap.c:783 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7da0aa2d9ca0, count: -12 ddb> show registers rdi 0xffff800019a42000 rsi 0 rbp 0xffff80002a79b220 rbx 0x4000 __ALIGN_SIZE+0x3000 rdx 0 rcx 0x800 rax 0 r8 0x4000 __ALIGN_SIZE+0x3000 r9 0xffff80002a79b178 r10 0xf6ccc230191183bc r11 0xffff800019a42000 r12 0 r13 0xfffff6806e527300 r14 0xfffff6806d39d558 r15 0x1 rip 0xffffffff832415e2 memset+0x52 cs 0x8 rflags 0x10206 __ALIGN_SIZE+0xf206 rsp 0xffff80002a79b0a8 ss 0x10 memset+0x52: repe stosq %es:(%rdi) ddb> show proc PROC (syz-executor) tid=464137 pid=25546 tcnt=1 stat=onproc flags process=1004 proc=0 runpri=50, usrpri=86, slppri=32, nice=20 wchan=0x0, wmesg=, ps_single=0xffff80002a77d240 scnt=0 ecnt=0 forw=0xffffffffffffffff, list=0xffff80002a77d770,0xffffffff83a27378 process=0xffff800045ffa898 user=0xffff80002a796000, vmspace=0xfffff6807f22d000 estcpu=36, cpticks=2, pctcpu=0.0, user=0, sys=2, intr=0 ddb> ps PID TID PPID UID S PRLAGS PFLAGS WAIT COMMAND *25546 464137 1 0 7 0x1004 0 syz-executor 63449 23996 1 0 3 0x100003 0x80 ttyin getty 9862 506149 0 0 3 0x14000 0x200 bored smr 96918 397344 0 0 2 0x14000 0x200 zerothread 37965 94956 0 0 3 0x14000 0x200 aiodoned aiodoned 8744 468416 0 0 3 0x14000 0x200 syncer update 64888 371597 0 0 3 0x14000 0x200 cleaner cleaner 15180 72016 0 0 3 0x14000 0x200 reaper reaper 70398 948 0 0 3 0x14000 0x200 pgdaemon pagedaemon 81107 102449 0 0 3 0x14000 0x200 bored viomb 59426 72852 0 0 3 0x14000 0x40000200 acpi0 acpi0 45449 456650 0 0 3 0x14000 0x200 bored softnet0 18854 32422 0 0 2 0x14000 0x200 systqmp 44761 386360 0 0 3 0x14000 0x200 bored systq 42814 172015 0 0 2 0x14000 0x40000200 softclock 38117 1592 0 0 3 0x14000 0x40000200 idle0 1 304730 0 0 3 0x2 0x80 wait init 0 0 -1 0 3 0x10000 0x200 scheduler swapper ddb>