panic: malformed IPv4 option passed to ip_optcopy Stopped at db_enter+0x18: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND 108647 12233 32767 0x10 0 1 syz-executor1 *413985 12233 32767 0x10 0x4000000 0K syz-executor1 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(29fc5bbcd7a98b7,ffffff006fb346d9,ffff800000173290) at ip_fragment+0x625 ip_output(670ba4b3388354dc,ffffff006f4ae230,ffffff006fb34600,0,ffffff006f1b2a00,ffffff006e8e5908) at ip_output+0xc8d sys/netinet/ip_output.c:501 udp_output(ba12d78a13c48b38,1bfa,ffffff006e8e5908,0) at udp_output+0x45a sys/netinet/udp_usrreq.c:1004 sosend(6fffd1371f4af242,ffffff0068bc4968,ffff800021135a10,806,ffff800021135ac0,0) at sosend+0x47a sys/kern/uipc_socket.c:513 dofilewritev(307ad4db86bb9f87,ffff80002108b788,ffff800021135ac0,806,ffff800021135ad8) at dofilewritev+0x14b sys/kern/sys_generic.c:364 sys_write(22d693fdcf3b6a42,40,ffff80002108b788) at sys_write+0x7b sys/kern/sys_generic.c:283 syscall(fee27423ec1bbd7e) at syscall+0x496 mi_syscall sys/sys/syscall_mi.h:99 [inline] syscall(fee27423ec1bbd7e) at syscall+0x496 sys/arch/amd64/amd64/trap.c:583 Xsyscall(6,0,c,0,3,5fe979b3010) at Xsyscall+0x128 end of kernel end trace frame: 0x600ccd3a140, 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(29fc5bbcd7a98b7,ffffff006fb346d9,ffff800000173290) at ip_fragment+0x625 ip_output(670ba4b3388354dc,ffffff006f4ae230,ffffff006fb34600,0,ffffff006f1b2a00,ffffff006e8e5908) at ip_output+0xc8d sys/netinet/ip_output.c:501 udp_output(ba12d78a13c48b38,1bfa,ffffff006e8e5908,0) at udp_output+0x45a sys/netinet/udp_usrreq.c:1004 sosend(6fffd1371f4af242,ffffff0068bc4968,ffff800021135a10,806,ffff800021135ac0,0) at sosend+0x47a sys/kern/uipc_socket.c:513 dofilewritev(307ad4db86bb9f87,ffff80002108b788,ffff800021135ac0,806,ffff800021135ad8) at dofilewritev+0x14b sys/kern/sys_generic.c:364 sys_write(22d693fdcf3b6a42,40,ffff80002108b788) at sys_write+0x7b sys/kern/sys_generic.c:283 syscall(fee27423ec1bbd7e) at syscall+0x496 mi_syscall sys/sys/syscall_mi.h:99 [inline] syscall(fee27423ec1bbd7e) at syscall+0x496 sys/arch/amd64/amd64/trap.c:583 Xsyscall(6,0,c,0,3,5fe979b3010) at Xsyscall+0x128 end of kernel end trace frame: 0x600ccd3a140, count: -10 ddb{0}> show registers rdi 0xffffffff81f00128 kprintf_mutex rsi 0xffffffff81150e07 db_enter+0x17 rbp 0xffff800021135640 rbx 0xffff8000211356e0 rdx 0xffff80000233d000 rcx 0x124c __ALIGN_SIZE+0x24c rax 0xffff80000233d000 r8 0xffff800021135610 r9 0 r10 0xc07c16d7881370fc r11 0x45ed28759279ee52 r12 0x3000000008 r13 0xffff800021135650 r14 0x100 r15 0xffffffff81cd528d apollo_udma100_tim+0xde73 rip 0xffffffff81150e08 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff800021135630 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{0}> show proc PROC (syz-executor1) pid=413985 stat=onproc flags process=10 proc=4000000 pri=79, usrpri=79, nice=20 forw=0xffffffffffffffff, list=0xffff80002108abd0,0xffffffff81f8d720 process=0xffff800021064358 user=0xffff800021130000, vmspace=0xffffff00659ff428 estcpu=36, cpticks=0, pctcpu=0.0 user=0, sys=0, intr=0 ddb{0}> ps PID TID PPID UID S FLAGS WAIT COMMAND 12233 108647 53517 32767 7 0x10 syz-executor1 *12233 413985 53517 32767 7 0x4000010 syz-executor1 90227 47748 89889 32767 3 0x90 nanosleep syz-executor0 89889 279923 45881 0 3 0x82 wait syz-executor0 53517 110716 79300 32767 3 0x90 nanosleep syz-executor1 79300 486589 45881 0 3 0x82 wait syz-executor1 73223 387681 0 0 3 0x14200 bored sosplice 45881 204061 40100 0 3 0x82 thrsleep syz-fuzzer 45881 104821 40100 0 3 0x4000082 nanosleep syz-fuzzer 45881 140537 40100 0 3 0x4000082 thrsleep syz-fuzzer 45881 29597 40100 0 3 0x4000082 thrsleep syz-fuzzer 45881 296709 40100 0 3 0x4000082 nanosleep syz-fuzzer 45881 436468 40100 0 3 0x4000082 thrsleep syz-fuzzer 45881 327309 40100 0 3 0x4000082 thrsleep syz-fuzzer 45881 520930 40100 0 3 0x4000082 thrsleep syz-fuzzer 45881 429203 40100 0 3 0x4000082 kqread syz-fuzzer 45881 254233 40100 0 3 0x4000082 thrsleep syz-fuzzer 40100 193513 1331 0 3 0x10008a pause ksh 1331 190723 76784 0 3 0x92 select sshd 27827 82644 1 0 3 0x100083 ttyin getty 76784 289577 1 0 3 0x80 select sshd 45892 278446 1576 73 3 0x100090 kqread syslogd 1576 503750 1 0 3 0x100082 netio syslogd 14410 285320 1 77 3 0x100090 poll dhclient 8152 519679 1 0 3 0x80 poll dhclient 80207 431059 0 0 3 0x14200 pgzero zerothread 97227 473998 0 0 3 0x14200 aiodoned aiodoned 2178 383443 0 0 3 0x14200 syncer update 95793 190477 0 0 3 0x14200 cleaner cleaner 67364 447132 0 0 3 0x14200 reaper reaper 28832 191286 0 0 3 0x14200 pgdaemon pagedaemon 77457 149954 0 0 3 0x14200 bored crynlk 94073 325656 0 0 3 0x14200 bored crypto 49863 163161 0 0 3 0x40014200 acpi0 acpi0 28997 444439 0 0 3 0x40014200 idle1 71151 494152 0 0 3 0x14200 bored softnet 87751 321159 0 0 3 0x14200 bored systqmp 77228 310655 0 0 3 0x14200 bored systq 79900 5347 0 0 3 0x40014200 bored softclock 86038 211746 0 0 3 0x40014200 idle0 1 522361 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper