panic: malformed IPv4 option passed to ip_optcopy Stopped at db_enter+0x18: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND 50032 59653 65534 0x10 0 1 syz-executor0 *219814 59653 65534 0x10 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(aae93cbca71e0d6d,ffffff007cb9aed9,ffff800000173290) at ip_fragment+0x625 ip_output(8308f4e1b90711aa,ffffff006f303c08,ffffff007cb9ae00,0,ffffff006ef3b500,ffffff006f304a80) at ip_output+0xc8d sys/netinet/ip_output.c:501 udp_output(416cb7c4ba156112,1400,ffffff006f304a80,0) at udp_output+0x45a sys/netinet/udp_usrreq.c:1004 sosend(79f0b96300b959ea,ffffff006e4a9da0,ffff80002118b130,ffff80002118b1e0,1000,0) at sosend+0x477 sys/kern/uipc_socket.c:513 dofilewritev(28a3c8eeded75bcd,ffff800021063788,ffff80002118b1e0,1000,ffff80002118b1f8) at dofilewritev+0x148 sys/kern/sys_generic.c:364 sys_write(1b566c42ee7eb6f7,40,ffff800021063788) at sys_write+0x7b sys/kern/sys_generic.c:283 syscall(4aa54e291fb1407c) at syscall+0x473 mi_syscall sys/sys/syscall_mi.h:99 [inline] syscall(4aa54e291fb1407c) at syscall+0x473 sys/arch/amd64/amd64/trap.c:583 Xsyscall(0,0,c,0,3,a9158e52010) at Xsyscall+0x128 end of kernel end trace frame: 0xa93cfb5be10, 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(aae93cbca71e0d6d,ffffff007cb9aed9,ffff800000173290) at ip_fragment+0x625 ip_output(8308f4e1b90711aa,ffffff006f303c08,ffffff007cb9ae00,0,ffffff006ef3b500,ffffff006f304a80) at ip_output+0xc8d sys/netinet/ip_output.c:501 udp_output(416cb7c4ba156112,1400,ffffff006f304a80,0) at udp_output+0x45a sys/netinet/udp_usrreq.c:1004 sosend(79f0b96300b959ea,ffffff006e4a9da0,ffff80002118b130,ffff80002118b1e0,1000,0) at sosend+0x477 sys/kern/uipc_socket.c:513 dofilewritev(28a3c8eeded75bcd,ffff800021063788,ffff80002118b1e0,1000,ffff80002118b1f8) at dofilewritev+0x148 sys/kern/sys_generic.c:364 sys_write(1b566c42ee7eb6f7,40,ffff800021063788) at sys_write+0x7b sys/kern/sys_generic.c:283 syscall(4aa54e291fb1407c) at syscall+0x473 mi_syscall sys/sys/syscall_mi.h:99 [inline] syscall(4aa54e291fb1407c) at syscall+0x473 sys/arch/amd64/amd64/trap.c:583 Xsyscall(0,0,c,0,3,a9158e52010) at Xsyscall+0x128 end of kernel end trace frame: 0xa93cfb5be10, count: -10 ddb{0}> show registers rdi 0xffffffff81f15558 kprintf_mutex rsi 0xffffffff8109bf47 db_enter+0x17 rbp 0xffff80002118ad60 rbx 0xffff80002118ae00 rdx 0xffff800000ad9000 rcx 0x18e1 __ALIGN_SIZE+0x8e1 rax 0xffff800000ad9000 r8 0xffff80002118ad30 r9 0 r10 0xd940bded85ea2816 r11 0x26b4e3b35a5abaac r12 0x3000000008 r13 0xffff80002118ad70 r14 0x100 r15 0xffffffff81c5f94c apollo_udma100_tim+0x10bae rip 0xffffffff8109bf48 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff80002118ad50 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{0}> show proc PROC (syz-executor0) pid=219814 stat=onproc flags process=10 proc=4000000 pri=52, usrpri=52, nice=20 forw=0xffffffffffffffff, list=0xffff8000210632d8,0xffffffff81fbf118 process=0xffff800021064010 user=0xffff800021186000, vmspace=0xffffff0065c52858 estcpu=36, cpticks=0, pctcpu=0.0 user=0, sys=0, intr=0 ddb{0}> ps PID TID PPID UID S FLAGS WAIT COMMAND 59653 50032 71003 65534 7 0x10 syz-executor0 *59653 219814 71003 65534 7 0x4000010 syz-executor0 71003 357108 45573 65534 3 0x90 nanosleep syz-executor0 45573 356017 5468 0 3 0x82 wait syz-executor0 32211 49880 19687 65534 3 0x90 nanosleep syz-executor1 19687 287564 5468 0 3 0x82 wait syz-executor1 94212 165645 0 0 3 0x14200 bored sosplice 5468 231214 52519 0 3 0x82 nanosleep syz-fuzzer 5468 276141 52519 0 3 0x4000082 nanosleep syz-fuzzer 5468 239434 52519 0 3 0x4000082 thrsleep syz-fuzzer 5468 57787 52519 0 3 0x4000082 thrsleep syz-fuzzer 5468 360561 52519 0 3 0x4000082 thrsleep syz-fuzzer 5468 224643 52519 0 3 0x4000082 thrsleep syz-fuzzer 5468 488464 52519 0 3 0x4000082 thrsleep syz-fuzzer 5468 231473 52519 0 3 0x4000082 thrsleep syz-fuzzer 5468 378648 52519 0 3 0x4000082 thrsleep syz-fuzzer 5468 503818 52519 0 3 0x4000082 thrsleep syz-fuzzer 5468 352555 52519 0 3 0x4000082 thrsleep syz-fuzzer 5468 505218 52519 0 3 0x4000082 thrsleep syz-fuzzer 52519 496282 17128 0 3 0x10008a pause ksh 17128 252704 26352 0 3 0x92 select sshd 36523 295064 1 0 3 0x100083 ttyin getty 26352 363947 1 0 3 0x80 select sshd 15751 327058 4710 73 3 0x100090 kqread syslogd 4710 194095 1 0 3 0x100082 netio syslogd 19112 465753 1 77 3 0x100090 poll dhclient 2452 503027 1 0 3 0x80 poll dhclient 37953 440924 0 0 3 0x14200 pgzero zerothread 14243 234963 0 0 3 0x14200 aiodoned aiodoned 8404 164650 0 0 3 0x14200 syncer update 43159 105368 0 0 3 0x14200 cleaner cleaner 57082 142618 0 0 3 0x14200 reaper reaper 41167 40700 0 0 3 0x14200 pgdaemon pagedaemon 52768 108306 0 0 3 0x14200 bored crynlk 95872 358671 0 0 3 0x14200 bored crypto 28896 188646 0 0 3 0x40014200 acpi0 acpi0 14540 123238 0 0 3 0x40014200 idle1 50998 423996 0 0 3 0x14200 bored softnet 32512 455057 0 0 3 0x14200 bored systqmp 75294 201869 0 0 3 0x14200 bored systq 81872 197645 0 0 3 0x40014200 bored softclock 2777 332358 0 0 3 0x40014200 idle0 1 471299 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper