panic: malformed IPv4 option passed to ip_optcopy Stopped at db_enter+0x18: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND *304025 4757 32767 0x10 0x4000000 1K syz-executor1 498664 35215 32767 0x10 0 0 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(25592eb838d056cc,ffffff006fb622b0,ffff800000173290) at ip_fragment+0x625 ip_output(630f24327929c10c,ffffff006f4a6af0,ffffff006f178500,0,ffffff006f178500,ffffff006f4a7900) at ip_output+0xc8d sys/netinet/ip_output.c:501 udp_output(8ad96dcf0572738d,138b,ffffff006f4a7900,0) at udp_output+0x45a sys/netinet/udp_usrreq.c:1004 sosend(34ae50bdaddb4876,ffffff006fa8a348,ffff800021188f08,1075,ffff800021189040,0) at sosend+0x47a sys/kern/uipc_socket.c:513 dofilewritev(25245385192c9188,0,4,ffff800021062bd0,ffff800021189040) at dofilewritev+0x14b sys/kern/sys_generic.c:364 sys_writev(49fceaaad698b91e,790,ffff800021062bd0) at sys_writev+0xdb sys/kern/sys_generic.c:310 syscall(25592eb8385f0225) at syscall+0x496 mi_syscall sys/sys/syscall_mi.h:99 [inline] syscall(25592eb8385f0225) at syscall+0x496 sys/arch/amd64/amd64/trap.c:583 Xsyscall(6,0,d,0,3,99ddfc86010) at Xsyscall+0x128 end of kernel end trace frame: 0x99fe5292f60, 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(25592eb838d056cc,ffffff006fb622b0,ffff800000173290) at ip_fragment+0x625 ip_output(630f24327929c10c,ffffff006f4a6af0,ffffff006f178500,0,ffffff006f178500,ffffff006f4a7900) at ip_output+0xc8d sys/netinet/ip_output.c:501 udp_output(8ad96dcf0572738d,138b,ffffff006f4a7900,0) at udp_output+0x45a sys/netinet/udp_usrreq.c:1004 sosend(34ae50bdaddb4876,ffffff006fa8a348,ffff800021188f08,1075,ffff800021189040,0) at sosend+0x47a sys/kern/uipc_socket.c:513 dofilewritev(25245385192c9188,0,4,ffff800021062bd0,ffff800021189040) at dofilewritev+0x14b sys/kern/sys_generic.c:364 sys_writev(49fceaaad698b91e,790,ffff800021062bd0) at sys_writev+0xdb sys/kern/sys_generic.c:310 syscall(25592eb8385f0225) at syscall+0x496 mi_syscall sys/sys/syscall_mi.h:99 [inline] syscall(25592eb8385f0225) at syscall+0x496 sys/arch/amd64/amd64/trap.c:583 Xsyscall(6,0,d,0,3,99ddfc86010) at Xsyscall+0x128 end of kernel end trace frame: 0x99fe5292f60, count: -10 ddb{1}> show registers rdi 0xffffffff81ee6a98 kprintf_mutex rsi 0xffffffff810774d7 db_enter+0x17 rbp 0xffff800021188b30 rbx 0xffff800021188bd0 rdx 0xffff800004343000 rcx 0x1894 __ALIGN_SIZE+0x894 rax 0xffff800004343000 r8 0xffff800021188b00 r9 0 r10 0x2468ccfb6cdbe356 r11 0xc7fb85265c6d6b66 r12 0x3000000008 r13 0xffff800021188b40 r14 0x100 r15 0xffffffff81cd35c1 substchar+0x1034c rip 0xffffffff810774d8 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff800021188b20 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{1}> show proc PROC (syz-executor1) pid=304025 stat=onproc flags process=10 proc=4000000 pri=74, usrpri=74, nice=20 forw=0xffffffffffffffff, list=0xffff800021063080,0xffff800021062028 process=0xffff800021065078 user=0xffff800021184000, vmspace=0xffffff0060df2a68 estcpu=36, cpticks=0, pctcpu=0.0 user=0, sys=0, intr=0 ddb{1}> ps PID TID PPID UID S FLAGS WAIT COMMAND 4757 475184 59557 32767 2 0x10 syz-executor1 * 4757 304025 59557 32767 7 0x4000010 syz-executor1 4757 6714 59557 32767 3 0x4000090 fsleep syz-executor1 35215 498664 31069 32767 7 0x10 syz-executor0 35215 59369 31069 32767 3 0x4000090 lockf syz-executor0 59557 45167 14550 32767 3 0x90 nanosleep syz-executor1 14550 235107 21653 0 3 0x82 wait syz-executor1 31069 442954 87136 32767 3 0x90 nanosleep syz-executor0 87136 224743 21653 0 3 0x82 wait syz-executor0 84023 426695 0 0 3 0x14200 bored sosplice 21653 305998 74785 0 3 0x82 thrsleep syz-fuzzer 21653 352796 74785 0 3 0x4000082 thrsleep syz-fuzzer 21653 209708 74785 0 3 0x4000082 thrsleep syz-fuzzer 21653 305356 74785 0 3 0x4000082 thrsleep syz-fuzzer 21653 416740 74785 0 3 0x4000082 thrsleep syz-fuzzer 21653 81610 74785 0 3 0x4000082 thrsleep syz-fuzzer 21653 461440 74785 0 3 0x4000082 thrsleep syz-fuzzer 21653 306959 74785 0 3 0x4000082 thrsleep syz-fuzzer 21653 479450 74785 0 3 0x4000082 thrsleep syz-fuzzer 21653 101346 74785 0 3 0x4000082 thrsleep syz-fuzzer 21653 213574 74785 0 3 0x4000082 thrsleep syz-fuzzer 21653 98291 74785 0 3 0x4000082 kqread syz-fuzzer 74785 439350 76171 0 3 0x10008a pause ksh 76171 424823 7084 0 3 0x92 select sshd 98434 507647 1 0 3 0x100083 ttyin getty 7084 79826 1 0 3 0x80 select sshd 49132 127346 36386 73 3 0x100090 kqread syslogd 36386 252836 1 0 3 0x100082 netio syslogd 26823 417898 1 77 3 0x100090 poll dhclient 78338 513699 1 0 3 0x80 poll dhclient 45030 493401 0 0 2 0x14200 zerothread 29566 33950 0 0 3 0x14200 aiodoned aiodoned 71876 152866 0 0 3 0x14200 syncer update 70844 218941 0 0 3 0x14200 cleaner cleaner 20566 56286 0 0 3 0x14200 reaper reaper 92308 187281 0 0 3 0x14200 pgdaemon pagedaemon 42191 514897 0 0 3 0x14200 bored crynlk 11421 152094 0 0 3 0x14200 bored crypto 71485 28946 0 0 3 0x40014200 acpi0 acpi0 83703 83938 0 0 3 0x40014200 idle1 15226 311749 0 0 3 0x14200 bored softnet 33228 49546 0 0 3 0x14200 bored systqmp 41108 445296 0 0 3 0x14200 bored systq 32753 101309 0 0 3 0x40014200 bored softclock 14683 21957 0 0 3 0x40014200 idle0 1 483354 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper