panic: m_copydata: null mbuf Stopped at db_enter+0x18: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND *266538 70037 0 0 0x4000000 0 syz-executor.1 db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:398 panic(ffffffff822245f3) at panic+0x15c sys/kern/subr_prf.c:207 m_copydata(fffffd8065c07300,808,8,fffffd805cbe3b20) at m_copydata+0x17e m_getptr sys/kern/uipc_mbuf.c:1031 [inline] m_copydata(fffffd8065c07300,808,8,fffffd805cbe3b20) at m_copydata+0x17e sys/kern/uipc_mbuf.c:722 ip6_pullexthdr(fffffd8065c07300,808,0) at ip6_pullexthdr+0x16f sys/netinet6/ip6_input.c:1175 ip6_savecontrol(fffffd805e4d9578,fffffd8065c07300,ffff80001d377c30) at ip6_savecontrol+0x373 sys/netinet6/ip6_input.c:1062 rip6_input(ffff80001d377e88,ffff80001d377e94,0,18) at rip6_input+0x75b sys/netinet6/raw_ip6.c:225 ip_deliver(ffff80001d377e88,ffff80001d377e94,0,18) at ip_deliver+0x2e3 sys/netinet/ip_input.c:668 ip6_input_if(ffff80001d377e88,ffff80001d377e94,29,0,ffff800000677800) at ip6_input_if+0x1055 ipv6_input(ffff800000677800,fffffd8065c07300) at ipv6_input+0x48 sys/netinet6/ip6_input.c:171 if_input_local(ffff800000677800,fffffd8065c07300,18) at if_input_local+0x121 sys/net/if.c:781 ip6_output(fffffd8065c07d00,ffff800000a02d00,fffffd805e4d9c78,0,0,fffffd805e4d9c08) at ip6_output+0xd02 rip6_output(fffffd8065c07500,fffffd805e4daa80,ffff80001d3781f0,0) at rip6_output+0x4d7 sys/netinet6/raw_ip6.c:481 rip6_usrreq(fffffd805e4daa80,9,fffffd8065c07500,0,0,ffff80001d420508) at rip6_usrreq+0x5e1 sys/netinet6/raw_ip6.c:670 sosend(fffffd805e4daa80,0,ffff80001d378438,0,0,0) at sosend+0x669 sys/kern/uipc_socket.c:524 end trace frame: 0xffff80001d378420, count: 0 https://www.openbsd.org/ddb.html describes the minimum info required in bug reports. Insufficient info makes it difficult to find and fix bugs.