login: panic: m_copym0: short mbuf chain Stopped at db_enter+0x18: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND *427595 53756 0 0x12 0 0 sshd db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:398 panic(ffffffff823b5637) at panic+0x15c sys/kern/subr_prf.c:207 m_copym(fffffd805c65c400,294,1ac,2) at m_copym+0x553 sys/kern/uipc_mbuf.c:695 tcp_output(ffff800000abfee0) at tcp_output+0x154d sys/netinet/tcp_output.c:673 tcp_usrreq(fffffd805da6f328,9,fffffd805c65c300,0,0,ffff80001d717eb0) at tcp_usrreq+0xa54 sosend(fffffd805da6f328,0,ffff80001d71e7d8,0,0,80) at sosend+0x669 sys/kern/uipc_socket.c:555 dofilewritev(ffff80001d717eb0,4,ffff80001d71e7d8,0,ffff80001d71e8c0) at dofilewritev+0x1ab sys/kern/sys_generic.c:365 sys_write(ffff80001d717eb0,ffff80001d71e870,ffff80001d71e8c0) at sys_write+0x83 sys/kern/sys_generic.c:285 syscall(ffff80001d71e940) at syscall+0x507 sys/arch/amd64/amd64/trap.c:570 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7f7ffffc4b90, 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> ddb> set $lines = 0 ddb> set $maxwidth = 0 ddb> show panic m_copym0: short mbuf chain ddb> trace db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:398 panic(ffffffff823b5637) at panic+0x15c sys/kern/subr_prf.c:207 m_copym(fffffd805c65c400,294,1ac,2) at m_copym+0x553 sys/kern/uipc_mbuf.c:695 tcp_output(ffff800000abfee0) at tcp_output+0x154d sys/netinet/tcp_output.c:673 tcp_usrreq(fffffd805da6f328,9,fffffd805c65c300,0,0,ffff80001d717eb0) at tcp_usrreq+0xa54 sosend(fffffd805da6f328,0,ffff80001d71e7d8,0,0,80) at sosend+0x669 sys/kern/uipc_socket.c:555 dofilewritev(ffff80001d717eb0,4,ffff80001d71e7d8,0,ffff80001d71e8c0) at dofilewritev+0x1ab sys/kern/sys_generic.c:365 sys_write(ffff80001d717eb0,ffff80001d71e870,ffff80001d71e8c0) at sys_write+0x83 sys/kern/sys_generic.c:285 syscall(ffff80001d71e940) at syscall+0x507 sys/arch/amd64/amd64/trap.c:570 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7f7ffffc4b90, count: -10 ddb> show registers rdi 0 rsi 0x1 rbp 0xffff80001d71e2a0 rbx 0xffff80001d71e350 rdx 0x2 rcx 0 rax 0x1 r8 0xffffffff822e7d3f kprintf+0x15f r9 0x1 r10 0x2 r11 0xb6ebfab54829ae46 r12 0x3000000008 r13 0xffff80001d71e2b0 r14 0x100 r15 0x1 rip 0xffffffff81b9cc28 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff80001d71e290 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb> show proc PROC (sshd) pid=427595 stat=onproc flags process=12 proc=0 pri=24, usrpri=50, nice=20 forw=0xffffffffffffffff, list=0xffff80001d718870,0xffff80001d717020 process=0xffff8000ffff8ae0 user=0xffff80001d719000, vmspace=0xfffffd806bc0a550 estcpu=0, cpticks=0, pctcpu=0.0 user=0, sys=0, intr=0 ddb> ps PID TID PPID UID S FLAGS WAIT COMMAND 77208 514751 45998 0 2 0x2 syz-executor.0 37997 426824 45998 0 2 0x2 syz-executor.1 45998 422180 29618 0 3 0x82 thrsleep syz-fuzzer 45998 130034 29618 0 3 0x4000082 nanosleep syz-fuzzer 45998 6313 29618 0 3 0x4000082 thrsleep syz-fuzzer 45998 192376 29618 0 3 0x4000082 thrsleep syz-fuzzer 45998 124795 29618 0 2 0x4000002 syz-fuzzer 45998 114100 29618 0 3 0x4000082 thrsleep syz-fuzzer 45998 42172 29618 0 3 0x4000082 thrsleep syz-fuzzer 29618 118060 53756 0 3 0x10008a pause ksh *53756 427595 68544 0 7 0x12 sshd 20249 487705 1 0 3 0x100083 ttyin getty 68544 257973 1 0 3 0x80 select sshd 72451 382080 13018 73 3 0x100090 kqread syslogd 13018 64057 1 0 3 0x100082 netio syslogd 35910 404020 1 77 3 0x100090 poll dhclient 48402 299422 1 0 3 0x80 poll dhclient 36971 466317 0 0 3 0x14200 bored smr 62470 134778 0 0 3 0x14200 pgzero zerothread 58298 395011 0 0 3 0x14200 aiodoned aiodoned 40795 311497 0 0 3 0x14200 syncer update 97340 349531 0 0 3 0x14200 cleaner cleaner 11787 269378 0 0 3 0x14200 reaper reaper 2209 234107 0 0 3 0x14200 pgdaemon pagedaemon 89414 299679 0 0 3 0x14200 bored crynlk 8059 290975 0 0 3 0x14200 bored crypto 30208 270266 0 0 3 0x40014200 acpi0 acpi0 72752 293665 0 0 3 0x14200 bored softnet 93041 114049 0 0 3 0x14200 bored systqmp 80210 116278 0 0 3 0x14200 bored systq 46599 431504 0 0 3 0x40014200 bored softclock 96238 165410 0 0 3 0x40014200 idle0 1 325687 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb> show all locks No such command ddb> show malloc Type InUse MemUse HighUse Limit Requests Type Lim devbuf 9491 6402K 6852K 78643K 11128 0 pcb 13 8K 8K 78643K 43 0 rtable 120 6K 6K 78643K 284 0 ifaddr 63 13K 13K 78643K 93 0 counters 21 16K 16K 78643K 22 0 ioctlops 0 0K 4K 78643K 49 0 iov 0 0K 12K 78643K 19 0 mount 1 1K 1K 78643K 1 0 vnodes 1225 77K 77K 78643K 1428 0 UFS quota 1 32K 32K 78643K 1 0 UFS mount 5 36K 36K 78643K 5 0 shm 2 1K 1K 78643K 2 0 VM map 2 0K 0K 78643K 2 0 sem 12 1K 1K 78643K 25 0 dirhash 12 2K 2K 78643K 12 0 ACPI 1809 195K 288K 78643K 12938 0 file desc 4 9K 25K 78643K 147 0 sigio 0 0K 0K 78643K 3 0 proc 49 38K 63K 78643K 370 0 subproc 32 2K 2K 78643K 34 0 NFS srvsock 1 0K 0K 78643K 1 0 NFS daemon 1 16K 16K 78643K 1 0 ip_moptions 0 0K 0K 78643K 4 0 in_multi 40 2K 2K 78643K 64 0 ether_multi 1 0K 0K 78643K 3 0 ISOFS mount 1 32K 32K 78643K 1 0 MSDOSFS mount 1 16K 16K 78643K 1 0 ttys 55 254K 254K 78643K 55 0 exec 0 0K 1K 78643K 198 0 pagedep 1 8K 8K 78643K 1 0 inodedep 1 32K 32K 78643K 1 0 newblk 1 0K 0K 78643K 1 0 VM swap 7 26K 26K 78643K 7 0 UVM amap 125 39K 39K 78643K 1183 0 UVM aobj 4 2K 2K 78643K 4 0 memdesc 1 4K 4K 78643K 1 0 crypto data 1 1K 1K 78643K 1 0 ip6_options 0 0K 0K 78643K 16 0 NDP 9 0K 0K 78643K 16 0 temp 83 3846K 3910K 78643K 4824 0 kqueue 3 4K 8K 78643K 10 0 SYN cache 2 16K 16K 78643K 2 0 ddb> show all pools Name Size Requests Fail Releases Pgreq Pgrel Npage Hiwat Minpg Maxpg Idle arp 64 6 0 0 1 0 1 1 0 8 0 rtpcb 80 23 0 21 1 0 1 1 0 8 0 rtentry 112 55 0 10 2 0 2 2 0 8 0 unpcb 120 406 0 398 1 0 1 1 0 8 0 syncache 264 4 0 4 1 1 0 1 0 8 0 tcpqe 32 41 0 41 1 1 0 1 0 8 0 tcpcb 544 37 0 33 1 0 1 1 0 8 0 inpcb 296 156 0 149 3 1 2 2 0 8 1 nd6 48 11 0 5 1 0 1 1 0 8 0 pkpcb 40 2 0 2 1 0 1 1 0 8 1 pfrktable 1344 28 0 22 2 1 1 1 0 8 0 pftag 88 4 0 2 2 1 1 1 0 8 0 pfrule 1360 8 0 4 2 1 1 1 0 8 0 art_heap8 4096 2 0 0 2 0 2 2 0 8 0 art_heap4 256 241 0 40 13 0 13 13 0 8 0 art_table 32 243 0 40 2 0 2 2 0 8 0 art_node 16 54 0 13 1 0 1 1 0 8 0 semupl 112 2 0 2 2 1 1 1 0 8 1 semapl 112 15 0 5 1 0 1 1 0 8 0 shmpl 112 2 0 0 1 0 1 1 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino2pl 256 1586 0 190 88 0 88 88 0 8 0 ffsino 240 1586 0 190 83 0 83 83 0 8 0 nchpl 144 1967 0 367 60 0 60 60 0 8 0 uvmvnodes 72 1814 0 0 33 0 33 33 0 8 0 vnodes 208 1814 0 0 96 0 96 96 0 8 0 namei 1024 5195 0 5194 3 2 1 1 0 8 0 vcpupl 1984 2 0 0 1 0 1 1 0 8 0 vmpool 528 2 0 0 1 0 1 1 0 8 0 pfiaddrpl 120 10 0 6 2 1 1 1 0 8 0 scxspl 192 6155 0 6155 2 1 1 1 0 8 1 plimitpl 152 20 0 13 1 0 1 1 0 8 0 sigapl 424 333 0 306 4 0 4 4 0 8 0 futexpl 56 2843 0 2843 3 2 1 1 0 8 1 knotepl 112 68 0 49 1 0 1 1 0 8 0 kqueuepl 144 16 0 14 1 0 1 1 0 8 0 pipelkpl 16 86 0 76 1 0 1 1 0 8 0 pipepl 120 172 0 153 1 0 1 1 0 8 0 fdescpl 432 319 0 306 2 0 2 2 0 8 0 filepl 120 2194 0 2099 4 0 4 4 0 8 1 lockfpl 104 36 0 35 1 0 1 1 0 8 0 lockfspl 48 10 0 9 1 0 1 1 0 8 0 sessionpl 112 17 0 7 1 0 1 1 0 8 0 pgrppl 48 17 0 7 1 0 1 1 0 8 0 ucredpl 96 175 0 168 1 0 1 1 0 8 0 zombiepl 144 306 0 306 1 0 1 1 0 8 1 processpl 920 333 0 306 4 0 4 4 0 8 0 procpl 624 477 0 444 5 1 4 4 0 8 1 sockpl 400 587 0 570 6 2 4 4 0 8 2 mcl64k 65536 8 0 8 1 0 1 1 0 8 1 mcl12k 12288 4 0 4 2 1 1 1 0 8 1 mcl8k 8192 3 0 3 2 1 1 1 0 8 1 mcl4k 4096 21 0 21 4 3 1 1 0 8 1 mcl2k 2048 75815 0 75769 16 9 7 13 0 8 0 mtagpl 96 8 0 2 2 1 1 1 0 8 0 mbufpl 256 120729 0 120596 14 1 13 13 0 8 1 bufpl 280 3882 0 128 269 0 269 269 0 8 0 anonpl 16 44831 0 29174 68 3 65 65 0 107 0 amapchunkpl 152 2060 0 1928 23 16 7 16 0 158 1 amappl16 192 1487 0 622 45 0 45 45 0 8 1 amappl15 184 9 0 7 1 0 1 1 0 8 0 amappl14 176 84 0 76 1 0 1 1 0 8 0 amappl13 168 26 0 23 1 0 1 1 0 8 0 amappl12 160 6 0 6 1 1 0 1 0 8 0 amappl11 152 47 0 38 1 0 1 1 0 8 0 amappl10 144 14 0 9 1 0 1 1 0 8 0 amappl9 136 424 0 421 1 0 1 1 0 8 0 amappl8 128 381 0 340 2 0 2 2 0 8 0 amappl7 120 107 0 95 1 0 1 1 0 8 0 amappl6 112 22 0 19 1 0 1 1 0 8 0 amappl5 104 287 0 276 1 0 1 1 0 8 0 amappl4 96 420 0 393 1 0 1 1 0 8 0 amappl3 88 159 0 154 1 0 1 1 0 8 0 amappl2 80 1729 0 1673 2 0 2 2 0 8 0 amappl1 72 15205 0 14807 24 15 9 17 0 8 0 amappl 80 706 0 665 2 0 2 2 0 84 0 dma4096 4096 1 0 1 1 1 0 1 0 8 0 dma256 256 6 0 6 1 1 0 1 0 8 0 dma128 128 253 0 253 1 1 0 1 0 8 0 dma64 64 6 0 6 1 1 0 1 0 8 0 dma32 32 7 0 7 1 1 0 1 0 8 0 dma16 16 18 0 17 1 0 1 1 0 8 0 aobjpl 64 3 0 0 1 0 1 1 0 8 0 uaddrrnd 24 321 0 306 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 321 0 306 1 0 1 1 0 8 0 vmmpekpl 168 6242 0 6216 2 0 2 2 0 8 0 vmmpepl 168 44829 0 42991 123 31 92 109 0 357 6 vmsppl 272 320 0 306 3 1 2 2 0 8 0 pdppl 4096 648 0 614 6 1 5 6 0 8 0 pvpl 32 150407 0 131863 164 8 156 157 0 265 4 pmappl 200 320 0 306 1 0 1 1 0 8 0 extentpl 40 53 0 36 1 0 1 1 0 8 0 phpool 112 254 0 24 7 0 7 7 0 8 0 ddb> machine ddbcpu 0 No such command ddb> trace db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:398 panic(ffffffff823b5637) at panic+0x15c sys/kern/subr_prf.c:207 m_copym(fffffd805c65c400,294,1ac,2) at m_copym+0x553 sys/kern/uipc_mbuf.c:695 tcp_output(ffff800000abfee0) at tcp_output+0x154d sys/netinet/tcp_output.c:673 tcp_usrreq(fffffd805da6f328,9,fffffd805c65c300,0,0,ffff80001d717eb0) at tcp_usrreq+0xa54 sosend(fffffd805da6f328,0,ffff80001d71e7d8,0,0,80) at sosend+0x669 sys/kern/uipc_socket.c:555 dofilewritev(ffff80001d717eb0,4,ffff80001d71e7d8,0,ffff80001d71e8c0) at dofilewritev+0x1ab sys/kern/sys_generic.c:365 sys_write(ffff80001d717eb0,ffff80001d71e870,ffff80001d71e8c0) at sys_write+0x83 sys/kern/sys_generic.c:285 syscall(ffff80001d71e940) at syscall+0x507 sys/arch/amd64/amd64/trap.c:570 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7f7ffffc4b90, count: -10 ddb> machine ddbcpu 1 No such command ddb> trace db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:398 panic(ffffffff823b5637) at panic+0x15c sys/kern/subr_prf.c:207 m_copym(fffffd805c65c400,294,1ac,2) at m_copym+0x553 sys/kern/uipc_mbuf.c:695 tcp_output(ffff800000abfee0) at tcp_output+0x154d sys/netinet/tcp_output.c:673 tcp_usrreq(fffffd805da6f328,9,fffffd805c65c300,0,0,ffff80001d717eb0) at tcp_usrreq+0xa54 sosend(fffffd805da6f328,0,ffff80001d71e7d8,0,0,80) at sosend+0x669 sys/kern/uipc_socket.c:555 dofilewritev(ffff80001d717eb0,4,ffff80001d71e7d8,0,ffff80001d71e8c0) at dofilewritev+0x1ab sys/kern/sys_generic.c:365 sys_write(ffff80001d717eb0,ffff80001d71e870,ffff80001d71e8c0) at sys_write+0x83 sys/kern/sys_generic.c:285 syscall(ffff80001d71e940) at syscall+0x507 sys/arch/amd64/amd64/trap.c:570 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7f7ffffc4b90, count: -10