panic: malformed IPv4 option passed to ip_optcopy Stopped at db_enter+0x18: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND 123635 75505 65534 0x10 0 0 syz-executor1 *226698 75505 65534 0x10 0x4000000 1K 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(1bf09d7bddaf0fc4,ffffff007bba98d9,ffff800000173290) at ip_fragment+0x625 ip_output(c19e57b3da0d05c2,ffffff006f3077a8,ffffff007bba9800,0,ffffff0072921600,ffffff006f308c00) at ip_output+0xc8d sys/netinet/ip_output.c:501 udp_output(d8afe98cb231a183,1400,ffffff006f308c00,0) at udp_output+0x45a sys/netinet/udp_usrreq.c:1004 sosend(86f0f0bbf9823549,ffffff0060e209e0,ffff800021173aa0,ffff800021173b50,1000,0) at sosend+0x477 sys/kern/uipc_socket.c:513 dofilewritev(e5e9c263a844d4d1,ffff800021063c38,ffff800021173b50,1000,ffff800021173b68) at dofilewritev+0x148 sys/kern/sys_generic.c:364 sys_write(9058e0c4b8085251,40,ffff800021063c38) at sys_write+0x7b sys/kern/sys_generic.c:283 syscall(9c5728472fd5ca24) at syscall+0x473 mi_syscall sys/sys/syscall_mi.h:99 [inline] syscall(9c5728472fd5ca24) at syscall+0x473 sys/arch/amd64/amd64/trap.c:583 Xsyscall(6,0,c,0,3,84fb3fa0010) at Xsyscall+0x128 end of kernel end trace frame: 0x851dd524e60, 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(1bf09d7bddaf0fc4,ffffff007bba98d9,ffff800000173290) at ip_fragment+0x625 ip_output(c19e57b3da0d05c2,ffffff006f3077a8,ffffff007bba9800,0,ffffff0072921600,ffffff006f308c00) at ip_output+0xc8d sys/netinet/ip_output.c:501 udp_output(d8afe98cb231a183,1400,ffffff006f308c00,0) at udp_output+0x45a sys/netinet/udp_usrreq.c:1004 sosend(86f0f0bbf9823549,ffffff0060e209e0,ffff800021173aa0,ffff800021173b50,1000,0) at sosend+0x477 sys/kern/uipc_socket.c:513 dofilewritev(e5e9c263a844d4d1,ffff800021063c38,ffff800021173b50,1000,ffff800021173b68) at dofilewritev+0x148 sys/kern/sys_generic.c:364 sys_write(9058e0c4b8085251,40,ffff800021063c38) at sys_write+0x7b sys/kern/sys_generic.c:283 syscall(9c5728472fd5ca24) at syscall+0x473 mi_syscall sys/sys/syscall_mi.h:99 [inline] syscall(9c5728472fd5ca24) at syscall+0x473 sys/arch/amd64/amd64/trap.c:583 Xsyscall(6,0,c,0,3,84fb3fa0010) at Xsyscall+0x128 end of kernel end trace frame: 0x851dd524e60, count: -10 ddb{1}> show registers rdi 0xffffffff81ee5310 kprintf_mutex rsi 0xffffffff810e80d7 db_enter+0x17 rbp 0xffff8000211736d0 rbx 0xffff800021173770 rdx 0xffff8000042e1000 rcx 0x1128 __ALIGN_SIZE+0x128 rax 0xffff8000042e1000 r8 0xffff8000211736a0 r9 0 r10 0xf009ccde4b4313aa r11 0xac71b710d7b62e02 r12 0x3000000008 r13 0xffff8000211736e0 r14 0x100 r15 0xffffffff81c5f925 apollo_udma100_tim+0x10a1d rip 0xffffffff810e80d8 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff8000211736c0 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{1}> show proc PROC (syz-executor1) pid=226698 stat=onproc flags process=10 proc=4000000 pri=82, usrpri=82, nice=20 forw=0xffffffffffffffff, list=0xffff800021063080,0xffffffff81faceb8 process=0xffff800021065708 user=0xffff80002116e000, vmspace=0xffffff0065929008 estcpu=36, cpticks=0, pctcpu=0.0 user=0, sys=0, intr=0 ddb{1}> ps PID TID PPID UID S FLAGS WAIT COMMAND 75505 123635 9638 65534 7 0x10 syz-executor1 *75505 226698 9638 65534 7 0x4000010 syz-executor1 58604 265974 65271 65534 3 0x90 nanosleep syz-executor0 65271 415458 34279 0 3 0x82 wait syz-executor0 9638 47581 74813 65534 3 0x90 nanosleep syz-executor1 74813 402669 34279 0 3 0x82 wait syz-executor1 22653 411489 0 0 3 0x14200 bored sosplice 34279 45717 15189 0 3 0x82 thrsleep syz-fuzzer 34279 203960 15189 0 3 0x4000082 nanosleep syz-fuzzer 34279 156358 15189 0 3 0x4000082 thrsleep syz-fuzzer 34279 66392 15189 0 3 0x4000082 kqread syz-fuzzer 34279 108689 15189 0 3 0x4000082 thrsleep syz-fuzzer 34279 322386 15189 0 3 0x4000082 thrsleep syz-fuzzer 34279 110487 15189 0 3 0x4000082 thrsleep syz-fuzzer 34279 149887 15189 0 3 0x4000082 nanosleep syz-fuzzer 34279 249301 15189 0 3 0x4000082 thrsleep syz-fuzzer 34279 248173 15189 0 3 0x4000082 thrsleep syz-fuzzer 15189 66236 5757 0 3 0x10008a pause ksh 5757 199756 25597 0 3 0x92 select sshd 84718 61443 1 0 3 0x100083 ttyin getty 25597 132968 1 0 3 0x80 select sshd 34304 312781 57208 73 3 0x100090 kqread syslogd 57208 444004 1 0 3 0x100082 netio syslogd 86330 80200 1 77 3 0x100090 poll dhclient 4973 212195 1 0 3 0x80 poll dhclient 66081 231968 0 0 3 0x14200 pgzero zerothread 36978 247489 0 0 3 0x14200 aiodoned aiodoned 33685 397606 0 0 3 0x14200 syncer update 82776 364826 0 0 3 0x14200 cleaner cleaner 51927 322886 0 0 3 0x14200 reaper reaper 30957 241733 0 0 3 0x14200 pgdaemon pagedaemon 90721 421712 0 0 3 0x14200 bored crynlk 25512 112588 0 0 3 0x14200 bored crypto 6164 479840 0 0 3 0x40014200 acpi0 acpi0 5340 150822 0 0 3 0x40014200 idle1 19922 143071 0 0 3 0x14200 bored softnet 10766 370305 0 0 3 0x14200 bored systqmp 71759 17003 0 0 3 0x14200 bored systq 69960 122144 0 0 3 0x40014200 bored softclock 87861 504135 0 0 3 0x40014200 idle0 1 28346 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper