panic: malformed IPv4 option passed to ip_optcopy Stopped at db_enter+0x18: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND 200622 28477 32767 0x10 0 1 syz-executor1 * 72161 28477 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(6c35ca310701ee7f,ffffff006f5182d9,ffff800000173290) at ip_fragment+0x625 ip_output(c19c76648fe7622b,ffffff006f4a6578,ffffff006f518200,0,ffffff0068231900,ffffff006e8f6c08) at ip_output+0xc8d sys/netinet/ip_output.c:501 udp_output(295838cf70a5f88d,1400,ffffff006e8f6c08,0) at udp_output+0x45a sys/netinet/udp_usrreq.c:1004 sosend(4245830218870e29,ffffff006fa8a1e0,ffff800021089420,1000,ffff8000210894d0,0) at sosend+0x47a sys/kern/uipc_socket.c:513 dofilewritev(7779b8bbf093a07b,ffff800021063080,ffff8000210894d0,1000,ffff8000210894e8) at dofilewritev+0x14b sys/kern/sys_generic.c:364 sys_write(625450222709fd6f,40,ffff800021063080) at sys_write+0x7b sys/kern/sys_generic.c:283 syscall(6c35ca31078eba96) at syscall+0x496 mi_syscall sys/sys/syscall_mi.h:99 [inline] syscall(6c35ca31078eba96) at syscall+0x496 sys/arch/amd64/amd64/trap.c:583 Xsyscall(0,0,c,0,3,c485499010) at Xsyscall+0x128 end of kernel end trace frame: 0xc6adf38b60, 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(6c35ca310701ee7f,ffffff006f5182d9,ffff800000173290) at ip_fragment+0x625 ip_output(c19c76648fe7622b,ffffff006f4a6578,ffffff006f518200,0,ffffff0068231900,ffffff006e8f6c08) at ip_output+0xc8d sys/netinet/ip_output.c:501 udp_output(295838cf70a5f88d,1400,ffffff006e8f6c08,0) at udp_output+0x45a sys/netinet/udp_usrreq.c:1004 sosend(4245830218870e29,ffffff006fa8a1e0,ffff800021089420,1000,ffff8000210894d0,0) at sosend+0x47a sys/kern/uipc_socket.c:513 dofilewritev(7779b8bbf093a07b,ffff800021063080,ffff8000210894d0,1000,ffff8000210894e8) at dofilewritev+0x14b sys/kern/sys_generic.c:364 sys_write(625450222709fd6f,40,ffff800021063080) at sys_write+0x7b sys/kern/sys_generic.c:283 syscall(6c35ca31078eba96) at syscall+0x496 mi_syscall sys/sys/syscall_mi.h:99 [inline] syscall(6c35ca31078eba96) at syscall+0x496 sys/arch/amd64/amd64/trap.c:583 Xsyscall(0,0,c,0,3,c485499010) at Xsyscall+0x128 end of kernel end trace frame: 0xc6adf38b60, count: -10 ddb{0}> show registers rdi 0xffffffff81ee6a98 kprintf_mutex rsi 0xffffffff810774d7 db_enter+0x17 rbp 0xffff800021089050 rbx 0xffff8000210890f0 rdx 0xffff80000213e000 rcx 0x1221 __ALIGN_SIZE+0x221 rax 0xffff80000213e000 r8 0xffff800021089020 r9 0 r10 0xaa81f665d2849d34 r11 0x3bad37d75311cff3 r12 0x3000000008 r13 0xffff800021089060 r14 0x100 r15 0xffffffff81cd35c1 substchar+0x1034c rip 0xffffffff810774d8 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff800021089040 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{0}> show proc PROC (syz-executor1) pid=72161 stat=onproc flags process=10 proc=4000000 pri=86, usrpri=86, nice=20 forw=0xffffffffffffffff, list=0xffff800021062720,0xffffffff81fb06c8 process=0xffff800021064d30 user=0xffff800021084000, vmspace=0xffffff007f66e850 estcpu=36, cpticks=1, pctcpu=0.0 user=0, sys=1, intr=0 ddb{0}> ps PID TID PPID UID S FLAGS WAIT COMMAND 28477 200622 85777 32767 7 0x10 syz-executor1 *28477 72161 85777 32767 7 0x4000010 syz-executor1 84832 518804 22557 32767 2 0x490 syz-executor0 22557 135987 45078 0 3 0x82 wait syz-executor0 85777 110368 66684 32767 3 0x90 nanosleep syz-executor1 66684 248927 45078 0 3 0x82 wait syz-executor1 62226 25851 0 0 3 0x14200 bored sosplice 45078 276804 32377 0 3 0x82 thrsleep syz-fuzzer 45078 393741 32377 0 3 0x4000082 nanosleep syz-fuzzer 45078 320873 32377 0 3 0x4000082 thrsleep syz-fuzzer 45078 234039 32377 0 3 0x4000082 thrsleep syz-fuzzer 45078 83524 32377 0 3 0x4000082 thrsleep syz-fuzzer 45078 281444 32377 0 3 0x4000082 thrsleep syz-fuzzer 45078 33027 32377 0 3 0x4000082 thrsleep syz-fuzzer 45078 478730 32377 0 3 0x4000082 thrsleep syz-fuzzer 45078 323727 32377 0 3 0x4000082 kqread syz-fuzzer 45078 125695 32377 0 3 0x4000082 thrsleep syz-fuzzer 32377 516764 63979 0 3 0x10008a pause ksh 63979 222412 19168 0 3 0x92 select sshd 83724 98966 1 0 3 0x100083 ttyin getty 19168 5907 1 0 3 0x80 select sshd 48360 44146 24000 73 3 0x100090 kqread syslogd 24000 129587 1 0 3 0x100082 netio syslogd 59018 395071 1 77 3 0x100090 poll dhclient 39 203110 1 0 3 0x80 poll dhclient 35355 357166 0 0 3 0x14200 pgzero zerothread 17162 212773 0 0 3 0x14200 aiodoned aiodoned 81972 252102 0 0 3 0x14200 syncer update 30921 387134 0 0 3 0x14200 cleaner cleaner 90472 98624 0 0 3 0x14200 reaper reaper 57645 485791 0 0 3 0x14200 pgdaemon pagedaemon 25849 442880 0 0 3 0x14200 bored crynlk 32415 2106 0 0 3 0x14200 bored crypto 14290 519399 0 0 3 0x40014200 acpi0 acpi0 85757 477886 0 0 3 0x40014200 idle1 56345 408745 0 0 3 0x14200 bored softnet 22837 106201 0 0 3 0x14200 bored systqmp 52270 112122 0 0 3 0x14200 bored systq 3728 332752 0 0 3 0x40014200 bored softclock 30142 19351 0 0 3 0x40014200 idle0 1 35234 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper