panic: malformed IPv4 option passed to ip_optcopy Stopped at db_enter+0x18: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND *458588 38981 65534 0x10 0x4000000 0 syz-executor0 186522 58063 0 0x2 0x4000000 1K syz-fuzzer 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(61407c8d8fc28d24,ffffff0069fa49b0,ffff800000173290) at ip_fragment+0x625 ip_output(67b48154a2c72a39,ffffff006f30c690,ffffff006d660000,0,ffffff006d660000,ffffff006e737d88) at ip_output+0xc8d sys/netinet/ip_output.c:501 udp_output(75493c37ceb9223,f8f,ffffff006e737d88,0) at udp_output+0x45a sys/netinet/udp_usrreq.c:1004 sosend(ed5cbb3f37898565,ffffff007a9fce88,ffff800021121898,ffff8000211219d0,1471,0) at sosend+0x477 sys/kern/uipc_socket.c:513 dofilewritev(f7bfc44bb58abff6,0,8,ffff800021062e28,ffff8000211219d0) at dofilewritev+0x148 sys/kern/sys_generic.c:364 sys_writev(5df4b0b3b960ba4b,790,ffff800021062e28) at sys_writev+0xdb sys/kern/sys_generic.c:310 syscall(925a3a9731159d04) at syscall+0x473 mi_syscall sys/sys/syscall_mi.h:99 [inline] syscall(925a3a9731159d04) at syscall+0x473 sys/arch/amd64/amd64/trap.c:583 Xsyscall(6,0,d,0,3,a1fd7406010) at Xsyscall+0x128 end of kernel end trace frame: 0xa228488dae0, 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(61407c8d8fc28d24,ffffff0069fa49b0,ffff800000173290) at ip_fragment+0x625 ip_output(67b48154a2c72a39,ffffff006f30c690,ffffff006d660000,0,ffffff006d660000,ffffff006e737d88) at ip_output+0xc8d sys/netinet/ip_output.c:501 udp_output(75493c37ceb9223,f8f,ffffff006e737d88,0) at udp_output+0x45a sys/netinet/udp_usrreq.c:1004 sosend(ed5cbb3f37898565,ffffff007a9fce88,ffff800021121898,ffff8000211219d0,1471,0) at sosend+0x477 sys/kern/uipc_socket.c:513 dofilewritev(f7bfc44bb58abff6,0,8,ffff800021062e28,ffff8000211219d0) at dofilewritev+0x148 sys/kern/sys_generic.c:364 sys_writev(5df4b0b3b960ba4b,790,ffff800021062e28) at sys_writev+0xdb sys/kern/sys_generic.c:310 syscall(925a3a9731159d04) at syscall+0x473 mi_syscall sys/sys/syscall_mi.h:99 [inline] syscall(925a3a9731159d04) at syscall+0x473 sys/arch/amd64/amd64/trap.c:583 Xsyscall(6,0,d,0,3,a1fd7406010) at Xsyscall+0x128 end of kernel end trace frame: 0xa228488dae0, count: -10 ddb{0}> show registers rdi 0xffffffff81ee5310 kprintf_mutex rsi 0xffffffff810e80d7 db_enter+0x17 rbp 0xffff8000211214c0 rbx 0xffff800021121560 rdx 0xffff8000040df000 rcx 0x1384 __ALIGN_SIZE+0x384 rax 0xffff8000040df000 r8 0xffff800021121490 r9 0 r10 0xbe304c56ccedb832 r11 0xb4b56b126ef0b326 r12 0x3000000008 r13 0xffff8000211214d0 r14 0x100 r15 0xffffffff81c5f925 apollo_udma100_tim+0x10a1d rip 0xffffffff810e80d8 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff8000211214b0 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{0}> show proc PROC (syz-executor0) pid=458588 stat=onproc flags process=10 proc=4000000 pri=86, usrpri=86, nice=20 forw=0xffffffffffffffff, list=0xffff8000210639e0,0xffffffff81faceb8 process=0xffff8000210653c0 user=0xffff80002111c000, vmspace=0xffffff007f124840 estcpu=36, cpticks=1, pctcpu=0.0 user=0, sys=1, intr=0 ddb{0}> ps PID TID PPID UID S FLAGS WAIT COMMAND 38981 501320 90717 65534 2 0x10 syz-executor0 *38981 458588 90717 65534 7 0x4000010 syz-executor0 33547 44381 88722 65534 2 0x490 syz-executor1 88722 202343 58063 0 3 0x82 wait syz-executor1 90717 451001 55790 65534 3 0x90 nanosleep syz-executor0 55790 37676 58063 0 3 0x82 wait syz-executor0 32001 37044 0 0 3 0x14200 bored sosplice 58063 208162 19840 0 3 0x82 thrsleep syz-fuzzer 58063 57649 19840 0 2 0x4000482 syz-fuzzer 58063 109319 19840 0 3 0x4000082 thrsleep syz-fuzzer 58063 166396 19840 0 3 0x4000082 thrsleep syz-fuzzer 58063 504920 19840 0 3 0x4000082 thrsleep syz-fuzzer 58063 131246 19840 0 3 0x4000082 thrsleep syz-fuzzer 58063 360588 19840 0 3 0x4000082 thrsleep syz-fuzzer 58063 138537 19840 0 3 0x4000082 thrsleep syz-fuzzer 58063 393034 19840 0 3 0x4000082 thrsleep syz-fuzzer 58063 20842 19840 0 3 0x4000082 thrsleep syz-fuzzer 58063 292705 19840 0 3 0x4000082 thrsleep syz-fuzzer 58063 186522 19840 0 7 0x4000002 syz-fuzzer 19840 202633 33349 0 3 0x10008a pause ksh 33349 24016 24787 0 3 0x92 select sshd 82182 283317 1 0 3 0x100083 ttyin getty 24787 304869 1 0 3 0x80 select sshd 73575 454295 24691 73 3 0x100090 kqread syslogd 24691 88730 1 0 3 0x100082 netio syslogd 2847 511134 1 77 3 0x100090 poll dhclient 95292 68976 1 0 3 0x80 poll dhclient 38361 471523 0 0 3 0x14200 pgzero zerothread 10070 147229 0 0 3 0x14200 aiodoned aiodoned 81717 188313 0 0 3 0x14200 syncer update 29758 344106 0 0 3 0x14200 cleaner cleaner 29568 375248 0 0 3 0x14200 reaper reaper 5321 218102 0 0 3 0x14200 pgdaemon pagedaemon 88713 502200 0 0 3 0x14200 bored crynlk 84698 187995 0 0 3 0x14200 bored crypto 12719 131244 0 0 3 0x40014200 acpi0 acpi0 70678 313422 0 0 3 0x40014200 idle1 7001 346165 0 0 3 0x14200 bored softnet 53882 435467 0 0 3 0x14200 bored systqmp 42229 444655 0 0 3 0x14200 bored systq 23939 179350 0 0 3 0x40014200 bored softclock 35053 486921 0 0 3 0x40014200 idle0 1 171896 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper