panic: malformed IPv4 option passed to ip_optcopy Stopped at db_enter+0x18: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND 58497 41384 0 0 0 0 syz-executor1 * 51546 41384 0 0 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(fbbb5b6ec73a801c,ffffff00079180d9,ffff800000173290) at ip_fragment+0x625 ip_output(7c88cabfc6f6e292,ffffff006f4b2118,ffffff0007918000,0,ffffff0064fe9100,ffffff0065349640) at ip_output+0xc8d sys/netinet/ip_output.c:501 udp_output(a0cbfeaf62df27ad,1400,ffffff0065349640,0) at udp_output+0x45a sys/netinet/udp_usrreq.c:1004 sosend(18eca730677044b3,ffffff006e64ef08,ffff8000211a5df0,1000,ffff8000211a5ea0,0) at sosend+0x47a sys/kern/uipc_socket.c:513 dofilewritev(9f501e74e1d2af4b,ffff8000210624c8,ffff8000211a5ea0,1000,ffff8000211a5eb8) at dofilewritev+0x14b sys/kern/sys_generic.c:364 sys_write(3f1cd99acbf64351,40,ffff8000210624c8) at sys_write+0x7b sys/kern/sys_generic.c:283 syscall(9f501e74e16d2064) at syscall+0x496 mi_syscall sys/sys/syscall_mi.h:99 [inline] syscall(9f501e74e16d2064) at syscall+0x496 sys/arch/amd64/amd64/trap.c:583 Xsyscall(6,0,c,0,3,e492691e010) at Xsyscall+0x128 end of kernel end trace frame: 0xe4beadde660, 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(fbbb5b6ec73a801c,ffffff00079180d9,ffff800000173290) at ip_fragment+0x625 ip_output(7c88cabfc6f6e292,ffffff006f4b2118,ffffff0007918000,0,ffffff0064fe9100,ffffff0065349640) at ip_output+0xc8d sys/netinet/ip_output.c:501 udp_output(a0cbfeaf62df27ad,1400,ffffff0065349640,0) at udp_output+0x45a sys/netinet/udp_usrreq.c:1004 sosend(18eca730677044b3,ffffff006e64ef08,ffff8000211a5df0,1000,ffff8000211a5ea0,0) at sosend+0x47a sys/kern/uipc_socket.c:513 dofilewritev(9f501e74e1d2af4b,ffff8000210624c8,ffff8000211a5ea0,1000,ffff8000211a5eb8) at dofilewritev+0x14b sys/kern/sys_generic.c:364 sys_write(3f1cd99acbf64351,40,ffff8000210624c8) at sys_write+0x7b sys/kern/sys_generic.c:283 syscall(9f501e74e16d2064) at syscall+0x496 mi_syscall sys/sys/syscall_mi.h:99 [inline] syscall(9f501e74e16d2064) at syscall+0x496 sys/arch/amd64/amd64/trap.c:583 Xsyscall(6,0,c,0,3,e492691e010) at Xsyscall+0x128 end of kernel end trace frame: 0xe4beadde660, count: -10 ddb{1}> show registers rdi 0xffffffff81efc328 kprintf_mutex rsi 0xffffffff816336e7 db_enter+0x17 rbp 0xffff8000211a5a20 rbx 0xffff8000211a5ac0 rdx 0xffff80000273d000 rcx 0x13c8 __ALIGN_SIZE+0x3c8 rax 0xffff80000273d000 r8 0xffff8000211a59f0 r9 0 r10 0xf19d80ecb6e61d28 r11 0xdd9c95cf6749406b r12 0x3000000008 r13 0xffff8000211a5a30 r14 0x100 r15 0xffffffff81cd5393 substchar+0xdfee rip 0xffffffff816336e8 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff8000211a5a10 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{1}> show proc PROC (syz-executor1) pid=51546 stat=onproc flags process=0 proc=4000000 pri=78, usrpri=78, nice=20 forw=0xffffffffffffffff, list=0xffff800021062bd0,0xffffffff81fc53e0 process=0xffff800021065a50 user=0xffff8000211a0000, vmspace=0xffffff007f124108 estcpu=36, cpticks=1, pctcpu=0.0 user=0, sys=1, intr=0 ddb{1}> ps PID TID PPID UID S FLAGS WAIT COMMAND 41384 58497 20355 0 7 0 syz-executor1 *41384 51546 20355 0 7 0x4000000 syz-executor1 46546 342077 76648 0 3 0x80 nanosleep syz-executor0 46546 281168 76648 0 3 0x4000080 ttyout syz-executor0 46546 114133 76648 0 3 0x4000080 fsleep syz-executor0 76648 8386 36000 0 3 0x82 nanosleep syz-executor0 2451 442608 1 0 3 0x100083 ttyin getty 22444 226341 0 0 3 0x14200 bored sosplice 20355 136038 36000 0 3 0x82 nanosleep syz-executor1 36000 486735 14915 0 3 0x82 thrsleep syz-fuzzer 36000 99436 14915 0 3 0x4000082 nanosleep syz-fuzzer 36000 148539 14915 0 3 0x4000082 thrsleep syz-fuzzer 36000 182810 14915 0 3 0x4000082 thrsleep syz-fuzzer 36000 453168 14915 0 3 0x4000082 thrsleep syz-fuzzer 36000 110204 14915 0 3 0x4000082 thrsleep syz-fuzzer 36000 53305 14915 0 3 0x4000082 thrsleep syz-fuzzer 36000 86083 14915 0 3 0x4000082 thrsleep syz-fuzzer 36000 303800 14915 0 3 0x4000082 thrsleep syz-fuzzer 36000 207719 14915 0 3 0x4000082 thrsleep syz-fuzzer 36000 137655 14915 0 3 0x4000082 kqread syz-fuzzer 14915 439706 90635 0 3 0x10008a pause ksh 90635 280381 91572 0 3 0x92 select sshd 91572 217565 1 0 3 0x80 select sshd 22778 161110 24213 73 3 0x100090 kqread syslogd 24213 513637 1 0 3 0x100082 netio syslogd 70800 223959 1 77 3 0x100090 poll dhclient 2671 43517 1 0 3 0x80 poll dhclient 26398 286942 0 0 3 0x14200 pgzero zerothread 88544 443104 0 0 3 0x14200 aiodoned aiodoned 17416 421266 0 0 3 0x14200 syncer update 7331 310826 0 0 3 0x14200 cleaner cleaner 31075 200108 0 0 3 0x14200 reaper reaper 94802 518885 0 0 3 0x14200 pgdaemon pagedaemon 37526 440854 0 0 3 0x14200 bored crynlk 40809 51437 0 0 3 0x14200 bored crypto 31519 70634 0 0 3 0x40014200 acpi0 acpi0 62887 516386 0 0 3 0x40014200 idle1 98858 443231 0 0 3 0x14200 bored softnet 74813 149651 0 0 3 0x14200 bored systqmp 52700 358854 0 0 3 0x14200 bored systq 53057 265665 0 0 3 0x40014200 bored softclock 73498 463570 0 0 3 0x40014200 idle0 1 275143 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper