panic: malformed IPv4 option passed to ip_optcopy Stopped at db_enter+0x18: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND 198720 94493 0 0 0 0 syz-executor5461 *149272 94493 0 0 0x4000000 1K syz-executor5461 db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:399 panic() at panic+0x147 sys/kern/subr_prf.c:208 ip_fragment(cf5c07fbf8856990,ffffff007f1433d9,ffff800000173290) at ip_fragment+0x625 ip_output(17d5a39689666dd0,ffffff006f307460,ffffff007f143300,0,ffffff006f016800,ffffff006f308c00) at ip_output+0xc8d sys/netinet/ip_output.c:501 udp_output(cf5c07fbf81f54fa,1400,ffffff006f308c00,0) at udp_output+0x45a sys/netinet/udp_usrreq.c:1004 sosend(58a7126b623f4bbc,ffffff006e4af260,ffff8000210e72c8,ffff8000210e7400,1000,0) at sosend+0x477 sys/kern/uipc_socket.c:513 dofilewritev(c5a2f71672af20b5,0,3,ffff8000210b4bc8,ffff8000210e7400) at dofilewritev+0x148 sys/kern/sys_generic.c:364 sys_writev(fbe5352a4b0548a4,790,ffff8000210b4bc8) at sys_writev+0xdb sys/kern/sys_generic.c:310 syscall(2d7fac4b52467d04) at syscall+0x473 mi_syscall sys/sys/syscall_mi.h:99 [inline] syscall(2d7fac4b52467d04) at syscall+0x473 sys/arch/amd64/amd64/trap.c:583 Xsyscall(6,0,10aec53c4a0,0,1083f18e108,1083f18e100) at Xsyscall+0x128 end of kernel end trace frame: 0x10afe8803d0, count: 5 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{1}> ddb{1}> set $lines = 0 ddb{1}> show panic malformed IPv4 option passed to ip_optcopy ddb{1}> trace db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:399 panic() at panic+0x147 sys/kern/subr_prf.c:208 ip_fragment(cf5c07fbf8856990,ffffff007f1433d9,ffff800000173290) at ip_fragment+0x625 ip_output(17d5a39689666dd0,ffffff006f307460,ffffff007f143300,0,ffffff006f016800,ffffff006f308c00) at ip_output+0xc8d sys/netinet/ip_output.c:501 udp_output(cf5c07fbf81f54fa,1400,ffffff006f308c00,0) at udp_output+0x45a sys/netinet/udp_usrreq.c:1004 sosend(58a7126b623f4bbc,ffffff006e4af260,ffff8000210e72c8,ffff8000210e7400,1000,0) at sosend+0x477 sys/kern/uipc_socket.c:513 dofilewritev(c5a2f71672af20b5,0,3,ffff8000210b4bc8,ffff8000210e7400) at dofilewritev+0x148 sys/kern/sys_generic.c:364 sys_writev(fbe5352a4b0548a4,790,ffff8000210b4bc8) at sys_writev+0xdb sys/kern/sys_generic.c:310 syscall(2d7fac4b52467d04) at syscall+0x473 mi_syscall sys/sys/syscall_mi.h:99 [inline] syscall(2d7fac4b52467d04) at syscall+0x473 sys/arch/amd64/amd64/trap.c:583 Xsyscall(6,0,10aec53c4a0,0,1083f18e108,1083f18e100) at Xsyscall+0x128 end of kernel end trace frame: 0x10afe8803d0, count: -10 ddb{1}> show registers rdi 0xffffffff81edbb38 kprintf_mutex rsi 0x5 rbp 0xffff8000210e6ef0 rbx 0xffff8000210e6f90 rdx 0x3fd rcx 0 rax 0x1 r8 0xffff8000210e6ec0 r9 0 r10 0x8989983e3d4cbb6c r11 0x1ecd66cd6e111d7c r12 0x3000000008 r13 0xffff8000210e6f00 r14 0x100 r15 0xffffffff81c5e947 substchar+0x10fc3 rip 0xffffffff811bca38 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff8000210e6ee0 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{1}> show proc PROC (syz-executor5461) pid=149272 stat=onproc flags process=0 proc=4000000 pri=51, usrpri=51, nice=20 forw=0xffffffffffffffff, list=0xffff8000210b4e20,0xffffffff81f734e0 process=0xffff80002109a018 user=0xffff8000210e2000, vmspace=0xffffff007f123528 estcpu=1, cpticks=1, pctcpu=0.0 user=0, sys=1, intr=0 ddb{1}> ps PID TID PPID UID S FLAGS WAIT COMMAND 94493 198720 43260 0 7 0 syz-executor5461 94493 162239 43260 0 3 0x4000080 fsleep syz-executor5461 94493 394784 43260 0 3 0x4000080 fsleep syz-executor5461 *94493 149272 43260 0 7 0x4000000 syz-executor5461 43260 274301 75395 0 3 0x82 nanosleep syz-executor5461 75395 450220 64241 0 3 0x10008a pause ksh 64241 303646 48657 0 3 0x92 select sshd 79547 114943 1 0 3 0x100083 ttyin getty 48657 227558 1 0 3 0x80 select sshd 96995 62829 52889 73 3 0x100090 kqread syslogd 52889 195501 1 0 3 0x100082 netio syslogd 54315 463431 1 77 3 0x100090 poll dhclient 73361 215428 1 0 3 0x80 poll dhclient 86678 514671 0 0 3 0x14200 pgzero zerothread 42358 218261 0 0 3 0x14200 aiodoned aiodoned 49820 313607 0 0 3 0x14200 syncer update 37386 150931 0 0 3 0x14200 cleaner cleaner 99507 369069 0 0 3 0x14200 reaper reaper 71626 455578 0 0 3 0x14200 pgdaemon pagedaemon 5952 290225 0 0 3 0x14200 bored crynlk 45274 204849 0 0 3 0x14200 bored crypto 64538 202509 0 0 3 0x40014200 acpi0 acpi0 65675 191149 0 0 3 0x40014200 idle1 54482 144785 0 0 3 0x14200 bored softnet 35473 495950 0 0 3 0x14200 bored systqmp 50658 228535 0 0 3 0x14200 bored systq 16489 118424 0 0 3 0x40014200 bored softclock 47302 104405 0 0 3 0x40014200 idle0 1 106821 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb{1}>