panic: malformed IPv4 option passed to ip_optcopy Stopped at db_enter+0x18: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND *395518 98426 32767 0x10 0x4000000 1K syz-executor1 219284 89310 0 0x2 0x4000000 0 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(e448fa87bcb8fa33,ffffff0069e67bb0,ffff800000173290) at ip_fragment+0x625 ip_output(fb2a65ab4dca25c2,ffffff006f4a5460,ffffff006da52700,0,ffffff006da52700,ffffff006e8df788) at ip_output+0xc8d sys/netinet/ip_output.c:501 udp_output(935f7133b59ef8aa,1dcc,ffffff006e8df788,0) at udp_output+0x45a sys/netinet/udp_usrreq.c:1004 sosend(b31164befba27c2,ffffff006e653e18,ffff800021135ce8,634,ffff800021135e20,0) at sosend+0x47a sys/kern/uipc_socket.c:513 dofilewritev(703974bbc0933f6c,0,9,ffff800021063790,ffff800021135e20) at dofilewritev+0x14b sys/kern/sys_generic.c:364 sys_writev(5406d3b72a90ae2e,790,ffff800021063790) at sys_writev+0xdb sys/kern/sys_generic.c:310 syscall(e448fa87bc37aeda) at syscall+0x496 mi_syscall sys/sys/syscall_mi.h:99 [inline] syscall(e448fa87bc37aeda) at syscall+0x496 sys/arch/amd64/amd64/trap.c:583 Xsyscall(6,0,d,0,3,ae7560e3010) at Xsyscall+0x128 end of kernel end trace frame: 0xae971582d00, 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(e448fa87bcb8fa33,ffffff0069e67bb0,ffff800000173290) at ip_fragment+0x625 ip_output(fb2a65ab4dca25c2,ffffff006f4a5460,ffffff006da52700,0,ffffff006da52700,ffffff006e8df788) at ip_output+0xc8d sys/netinet/ip_output.c:501 udp_output(935f7133b59ef8aa,1dcc,ffffff006e8df788,0) at udp_output+0x45a sys/netinet/udp_usrreq.c:1004 sosend(b31164befba27c2,ffffff006e653e18,ffff800021135ce8,634,ffff800021135e20,0) at sosend+0x47a sys/kern/uipc_socket.c:513 dofilewritev(703974bbc0933f6c,0,9,ffff800021063790,ffff800021135e20) at dofilewritev+0x14b sys/kern/sys_generic.c:364 sys_writev(5406d3b72a90ae2e,790,ffff800021063790) at sys_writev+0xdb sys/kern/sys_generic.c:310 syscall(e448fa87bc37aeda) at syscall+0x496 mi_syscall sys/sys/syscall_mi.h:99 [inline] syscall(e448fa87bc37aeda) at syscall+0x496 sys/arch/amd64/amd64/trap.c:583 Xsyscall(6,0,d,0,3,ae7560e3010) at Xsyscall+0x128 end of kernel end trace frame: 0xae971582d00, count: -10 ddb{1}> show registers rdi 0xffffffff81ee6a98 kprintf_mutex rsi 0xffffffff810774d7 db_enter+0x17 rbp 0xffff800021135910 rbx 0xffff8000211359b0 rdx 0xffff80000113c000 rcx 0x1641 __ALIGN_SIZE+0x641 rax 0xffff80000113c000 r8 0xffff8000211358e0 r9 0 r10 0x95c5bca77de50480 r11 0x83850fd50d82899c r12 0x3000000008 r13 0xffff800021135920 r14 0x100 r15 0xffffffff81cd35c1 substchar+0x1034c rip 0xffffffff810774d8 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff800021135900 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{1}> show proc PROC (syz-executor1) pid=395518 stat=onproc flags process=10 proc=4000000 pri=75, usrpri=75, nice=20 forw=0xffffffffffffffff, list=0xffff800021062278,0xffffffff81fb06c8 process=0xffff800021064010 user=0xffff800021130000, vmspace=0xffffff0065a1bc68 estcpu=36, cpticks=1, pctcpu=0.0 user=0, sys=1, intr=0 ddb{1}> ps PID TID PPID UID S FLAGS WAIT COMMAND 98426 51368 83753 32767 2 0x10 syz-executor1 *98426 395518 83753 32767 7 0x4000010 syz-executor1 83753 501317 90664 32767 3 0x90 nanosleep syz-executor1 90664 231982 89310 0 3 0x82 wait syz-executor1 87934 472147 97765 32767 3 0x10 biowait syz-executor0 97765 352565 89310 0 3 0x82 wait syz-executor0 52979 48232 0 0 3 0x14200 bored sosplice 89310 422116 75514 0 3 0x82 thrsleep syz-fuzzer 89310 117098 75514 0 3 0x4000082 nanosleep syz-fuzzer 89310 25859 75514 0 3 0x4000082 thrsleep syz-fuzzer 89310 396229 75514 0 3 0x4000082 thrsleep syz-fuzzer 89310 73387 75514 0 3 0x4000082 thrsleep syz-fuzzer 89310 22225 75514 0 3 0x4000082 thrsleep syz-fuzzer 89310 219284 75514 0 7 0x4000002 syz-fuzzer 89310 29134 75514 0 3 0x4000082 kqread syz-fuzzer 89310 57347 75514 0 3 0x4000082 thrsleep syz-fuzzer 89310 112762 75514 0 3 0x4000082 thrsleep syz-fuzzer 75514 158842 29533 0 3 0x10008a pause ksh 29533 431607 94322 0 3 0x92 select sshd 55054 80232 1 0 3 0x100083 ttyin getty 94322 523981 1 0 3 0x80 select sshd 66104 1372 22233 73 3 0x100090 kqread syslogd 22233 385610 1 0 3 0x100082 netio syslogd 44117 497848 1 77 3 0x100090 poll dhclient 57697 407374 1 0 3 0x80 poll dhclient 7563 309927 0 0 3 0x14200 pgzero zerothread 51373 478346 0 0 3 0x14200 aiodoned aiodoned 70247 96254 0 0 3 0x14200 syncer update 5091 349058 0 0 3 0x14200 cleaner cleaner 31259 335210 0 0 3 0x14200 reaper reaper 28537 171464 0 0 3 0x14200 pgdaemon pagedaemon 18682 36341 0 0 3 0x14200 bored crynlk 68866 43844 0 0 3 0x14200 bored crypto 82297 196962 0 0 3 0x40014200 acpi0 acpi0 51332 144657 0 0 3 0x40014200 idle1 18371 25081 0 0 3 0x14200 bored softnet 11836 291125 0 0 3 0x14200 bored systqmp 34174 392710 0 0 3 0x14200 bored systq 94078 383671 0 0 3 0x40014200 bored softclock 38469 212625 0 0 3 0x40014200 idle0 1 110218 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper