panic: malformed IPv4 option passed to ip_optcopy Stopped at db_enter+0x18: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND 63700 44129 32767 0x10 0 0 syz-executor0 *501564 44129 32767 0x10 0x4000000 1K 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(aefe12a67227d5bc,ffffff0069cf8ad9,ffff800000173290) at ip_fragment+0x625 ip_output(5142702e91836f91,ffffff006f4ab690,ffffff0069cf8a00,0,ffffff006da33200,ffffff006f4ac600) at ip_output+0xc8d sys/netinet/ip_output.c:501 udp_output(32509c5761bb9dc8,1400,ffffff006f4ac600,0) at udp_output+0x45a sys/netinet/udp_usrreq.c:1004 sosend(96d415b32f922d42,ffffff006fa8ad98,ffff800021171650,1000,ffff800021171700,0) at sosend+0x47a sys/kern/uipc_socket.c:513 dofilewritev(7bb33170ee976fc2,ffff800021063530,ffff800021171700,1000,ffff800021171718) at dofilewritev+0x14b sys/kern/sys_generic.c:364 sys_write(b68197d86209e90a,40,ffff800021063530) at sys_write+0x7b sys/kern/sys_generic.c:283 syscall(aefe12a672a88155) at syscall+0x496 mi_syscall sys/sys/syscall_mi.h:99 [inline] syscall(aefe12a672a88155) at syscall+0x496 sys/arch/amd64/amd64/trap.c:583 Xsyscall(6,0,c,0,3,86e9e4c1010) at Xsyscall+0x128 end of kernel end trace frame: 0x871028f4e30, 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(aefe12a67227d5bc,ffffff0069cf8ad9,ffff800000173290) at ip_fragment+0x625 ip_output(5142702e91836f91,ffffff006f4ab690,ffffff0069cf8a00,0,ffffff006da33200,ffffff006f4ac600) at ip_output+0xc8d sys/netinet/ip_output.c:501 udp_output(32509c5761bb9dc8,1400,ffffff006f4ac600,0) at udp_output+0x45a sys/netinet/udp_usrreq.c:1004 sosend(96d415b32f922d42,ffffff006fa8ad98,ffff800021171650,1000,ffff800021171700,0) at sosend+0x47a sys/kern/uipc_socket.c:513 dofilewritev(7bb33170ee976fc2,ffff800021063530,ffff800021171700,1000,ffff800021171718) at dofilewritev+0x14b sys/kern/sys_generic.c:364 sys_write(b68197d86209e90a,40,ffff800021063530) at sys_write+0x7b sys/kern/sys_generic.c:283 syscall(aefe12a672a88155) at syscall+0x496 mi_syscall sys/sys/syscall_mi.h:99 [inline] syscall(aefe12a672a88155) at syscall+0x496 sys/arch/amd64/amd64/trap.c:583 Xsyscall(6,0,c,0,3,86e9e4c1010) at Xsyscall+0x128 end of kernel end trace frame: 0x871028f4e30, count: -10 ddb{1}> show registers rdi 0xffffffff81ee6a98 kprintf_mutex rsi 0xffffffff810774d7 db_enter+0x17 rbp 0xffff800021171280 rbx 0xffff800021171320 rdx 0xffff800004344000 rcx 0x1365 __ALIGN_SIZE+0x365 rax 0xffff800004344000 r8 0xffff800021171250 r9 0 r10 0x7a9b2ea39472b824 r11 0x672f9848f0c13a8 r12 0x3000000008 r13 0xffff800021171290 r14 0x100 r15 0xffffffff81cd35c1 substchar+0x1034c rip 0xffffffff810774d8 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff800021171270 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{1}> show proc PROC (syz-executor0) pid=501564 stat=onproc flags process=10 proc=4000000 pri=72, usrpri=72, nice=20 forw=0xffffffffffffffff, list=0xffff800021062720,0xffffffff81fb06c8 process=0xffff80002109b080 user=0xffff80002116c000, vmspace=0xffffff0065990740 estcpu=36, cpticks=1, pctcpu=0.0 user=0, sys=1, intr=0 ddb{1}> ps PID TID PPID UID S FLAGS WAIT COMMAND 44129 63700 17485 32767 7 0x10 syz-executor0 *44129 501564 17485 32767 7 0x4000010 syz-executor0 35060 202494 86180 32767 3 0x90 nanosleep syz-executor1 86180 387401 92303 0 3 0x82 wait syz-executor1 17485 476575 4295 32767 3 0x90 nanosleep syz-executor0 4295 188963 92303 0 3 0x82 wait syz-executor0 19422 132627 0 0 3 0x14200 bored sosplice 92303 466327 40375 0 3 0x82 thrsleep syz-fuzzer 92303 459322 40375 0 3 0x4000082 nanosleep syz-fuzzer 92303 20283 40375 0 3 0x4000082 thrsleep syz-fuzzer 92303 505951 40375 0 3 0x4000082 thrsleep syz-fuzzer 92303 95919 40375 0 3 0x4000082 thrsleep syz-fuzzer 92303 267055 40375 0 3 0x4000082 thrsleep syz-fuzzer 92303 93915 40375 0 3 0x4000082 thrsleep syz-fuzzer 92303 376329 40375 0 3 0x4000082 nanosleep syz-fuzzer 92303 492036 40375 0 3 0x4000082 thrsleep syz-fuzzer 92303 376598 40375 0 3 0x4000082 thrsleep syz-fuzzer 40375 184779 72471 0 3 0x10008a pause ksh 72471 432890 56433 0 3 0x92 select sshd 62651 264899 1 0 3 0x100083 ttyin getty 56433 27534 1 0 3 0x80 select sshd 71892 229603 66357 73 3 0x100090 kqread syslogd 66357 422031 1 0 3 0x100082 netio syslogd 64740 132973 1 77 3 0x100090 poll dhclient 7370 338423 1 0 3 0x80 poll dhclient 3280 406873 0 0 3 0x14200 pgzero zerothread 16812 110472 0 0 3 0x14200 aiodoned aiodoned 97516 193972 0 0 3 0x14200 syncer update 98222 233350 0 0 3 0x14200 cleaner cleaner 44694 346147 0 0 3 0x14200 reaper reaper 31338 508635 0 0 3 0x14200 pgdaemon pagedaemon 40757 69039 0 0 3 0x14200 bored crynlk 62551 43069 0 0 3 0x14200 bored crypto 18601 398467 0 0 3 0x40014200 acpi0 acpi0 73420 114533 0 0 3 0x40014200 idle1 4436 148398 0 0 3 0x14200 bored softnet 31372 18003 0 0 3 0x14200 bored systqmp 52990 499783 0 0 3 0x14200 bored systq 36916 198717 0 0 3 0x40014200 bored softclock 38177 30317 0 0 3 0x40014200 idle0 1 378963 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper