panic: malformed IPv4 option passed to ip_optcopy Stopped at db_enter+0x18: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND 235381 90851 0 0 0 1 syz-executor0 *257188 90851 0 0 0x4000000 0K syz-executor0 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(52a860e245bd25,ffffff007acaa7b0,ffff800000173290) at ip_fragment+0x625 ip_output(548934e4e55e334e,ffffff006f306118,ffffff007448d400,0,ffffff007448d400,ffffff006e721d88) at ip_output+0xc8d sys/netinet/ip_output.c:501 udp_output(db7469a3860924aa,11da,ffffff006e721d88,0) at udp_output+0x45a sys/netinet/udp_usrreq.c:1004 sosend(d08eb3beb81847e3,ffffff0067dfabc8,ffff80002114b1a8,ffff80002114b2e0,1226,0) at sosend+0x477 sys/kern/uipc_socket.c:513 dofilewritev(cf8166e07f9ddd62,0,5,ffff800021063788,ffff80002114b2e0) at dofilewritev+0x148 sys/kern/sys_generic.c:364 sys_writev(3fb39c5da3dcaaac,790,ffff800021063788) at sys_writev+0xdb sys/kern/sys_generic.c:310 syscall(83fcb890f6c9d0f4) at syscall+0x473 mi_syscall sys/sys/syscall_mi.h:99 [inline] syscall(83fcb890f6c9d0f4) at syscall+0x473 sys/arch/amd64/amd64/trap.c:583 Xsyscall(6,0,d,0,3,4eeb3ef10d8) at Xsyscall+0x128 end of kernel end trace frame: 0x4f0cf4ee000, 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{0}> ddb{0}> set $lines = 0 ddb{0}> show panic malformed IPv4 option passed to ip_optcopy ddb{0}> 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(52a860e245bd25,ffffff007acaa7b0,ffff800000173290) at ip_fragment+0x625 ip_output(548934e4e55e334e,ffffff006f306118,ffffff007448d400,0,ffffff007448d400,ffffff006e721d88) at ip_output+0xc8d sys/netinet/ip_output.c:501 udp_output(db7469a3860924aa,11da,ffffff006e721d88,0) at udp_output+0x45a sys/netinet/udp_usrreq.c:1004 sosend(d08eb3beb81847e3,ffffff0067dfabc8,ffff80002114b1a8,ffff80002114b2e0,1226,0) at sosend+0x477 sys/kern/uipc_socket.c:513 dofilewritev(cf8166e07f9ddd62,0,5,ffff800021063788,ffff80002114b2e0) at dofilewritev+0x148 sys/kern/sys_generic.c:364 sys_writev(3fb39c5da3dcaaac,790,ffff800021063788) at sys_writev+0xdb sys/kern/sys_generic.c:310 syscall(83fcb890f6c9d0f4) at syscall+0x473 mi_syscall sys/sys/syscall_mi.h:99 [inline] syscall(83fcb890f6c9d0f4) at syscall+0x473 sys/arch/amd64/amd64/trap.c:583 Xsyscall(6,0,d,0,3,4eeb3ef10d8) at Xsyscall+0x128 end of kernel end trace frame: 0x4f0cf4ee000, count: -10 ddb{0}> show registers rdi 0xffffffff81f13dc0 kprintf_mutex rsi 0xffffffff81700707 db_enter+0x17 rbp 0xffff80002114add0 rbx 0xffff80002114ae70 rdx 0xffff800000cd9000 rcx 0x14fd __ALIGN_SIZE+0x4fd rax 0xffff800000cd9000 r8 0xffff80002114ada0 r9 0 r10 0x86b5feab99b61999 r11 0x75169a6e8b6277b8 r12 0x3000000008 r13 0xffff80002114ade0 r14 0x100 r15 0xffffffff81c5c0d7 apollo_udma100_tim+0xc1e6 rip 0xffffffff81700708 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff80002114adc0 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{0}> show proc PROC (syz-executor0) pid=257188 stat=onproc flags process=0 proc=4000000 pri=80, usrpri=80, nice=20 forw=0xffffffffffffffff, list=0xffff8000210632d8,0xffffffff81f92100 process=0xffff800021065a50 user=0xffff800021146000, vmspace=0xffffff007f124d68 estcpu=36, cpticks=1, pctcpu=0.0 user=0, sys=1, intr=0 ddb{0}> ps PID TID PPID UID S FLAGS WAIT COMMAND 90851 235381 20370 0 7 0 syz-executor0 90851 2544 20370 0 3 0x4000080 fsleep syz-executor0 *90851 257188 20370 0 7 0x4000000 syz-executor0 15950 242663 1 0 3 0x100083 ttyin getty 4910 311743 0 0 3 0x14200 bored sosplice 8398 287672 82891 0 3 0x82 nanosleep syz-executor1 20370 501230 82891 0 3 0x82 nanosleep syz-executor0 82891 310968 73407 0 3 0x82 thrsleep syz-fuzzer 82891 400511 73407 0 3 0x4000082 nanosleep syz-fuzzer 82891 524247 73407 0 3 0x4000082 thrsleep syz-fuzzer 82891 141944 73407 0 3 0x4000082 thrsleep syz-fuzzer 82891 441368 73407 0 3 0x4000082 thrsleep syz-fuzzer 82891 392498 73407 0 3 0x4000082 thrsleep syz-fuzzer 82891 297439 73407 0 3 0x4000082 thrsleep syz-fuzzer 82891 484534 73407 0 3 0x4000082 thrsleep syz-fuzzer 82891 313779 73407 0 3 0x4000082 kqread syz-fuzzer 82891 6377 73407 0 3 0x4000082 thrsleep syz-fuzzer 82891 470053 73407 0 3 0x4000082 thrsleep syz-fuzzer 73407 263125 94216 0 3 0x10008a pause ksh 94216 307674 52332 0 3 0x92 select sshd 52332 26732 1 0 3 0x80 select sshd 72266 228303 92694 73 3 0x100090 kqread syslogd 92694 203963 1 0 3 0x100082 netio syslogd 9686 468490 1 77 3 0x100090 poll dhclient 72345 305227 1 0 3 0x80 poll dhclient 61792 129994 0 0 3 0x14200 pgzero zerothread 52785 207866 0 0 3 0x14200 aiodoned aiodoned 26569 88593 0 0 3 0x14200 syncer update 11473 215786 0 0 3 0x14200 cleaner cleaner 29516 27693 0 0 3 0x14200 reaper reaper 64790 64285 0 0 3 0x14200 pgdaemon pagedaemon 90472 131105 0 0 3 0x14200 bored crynlk 25443 384610 0 0 3 0x14200 bored crypto 16236 464870 0 0 3 0x40014200 acpi0 acpi0 39982 223056 0 0 3 0x40014200 idle1 18871 467575 0 0 3 0x14200 bored softnet 56044 214313 0 0 3 0x14200 bored systqmp 65788 204832 0 0 3 0x14200 bored systq 27971 343662 0 0 2 0x40014200 softclock 43540 215324 0 0 3 0x40014200 idle0 1 167955 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper