login: panic: m_copym0: short mbuf chain Stopped at db_enter+0x18: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND *132727 23782 0 0x12 0 0 sshd db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:398 panic(ffffffff823b0c02) at panic+0x15c sys/kern/subr_prf.c:207 m_copym(fffffd80594c5f00,35c,19c,2) at m_copym+0x553 sys/kern/uipc_mbuf.c:695 tcp_output(ffff800000ac0760) at tcp_output+0x154d sys/netinet/tcp_output.c:673 tcp_usrreq(fffffd805da687d8,9,fffffd80594c5e00,0,0,ffff80001d717280) at tcp_usrreq+0xa54 sosend(fffffd805da687d8,0,ffff80001d71ea98,0,0,80) at sosend+0x669 sys/kern/uipc_socket.c:555 dofilewritev(ffff80001d717280,4,ffff80001d71ea98,0,ffff80001d71eb80) at dofilewritev+0x1ab sys/kern/sys_generic.c:365 sys_write(ffff80001d717280,ffff80001d71eb30,ffff80001d71eb80) at sys_write+0x83 sys/kern/sys_generic.c:285 syscall(ffff80001d71ec00) at syscall+0x507 sys/arch/amd64/amd64/trap.c:570 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7f7ffffcbfc0, 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(ffffffff823b0c02) at panic+0x15c sys/kern/subr_prf.c:207 m_copym(fffffd80594c5f00,35c,19c,2) at m_copym+0x553 sys/kern/uipc_mbuf.c:695 tcp_output(ffff800000ac0760) at tcp_output+0x154d sys/netinet/tcp_output.c:673 tcp_usrreq(fffffd805da687d8,9,fffffd80594c5e00,0,0,ffff80001d717280) at tcp_usrreq+0xa54 sosend(fffffd805da687d8,0,ffff80001d71ea98,0,0,80) at sosend+0x669 sys/kern/uipc_socket.c:555 dofilewritev(ffff80001d717280,4,ffff80001d71ea98,0,ffff80001d71eb80) at dofilewritev+0x1ab sys/kern/sys_generic.c:365 sys_write(ffff80001d717280,ffff80001d71eb30,ffff80001d71eb80) at sys_write+0x83 sys/kern/sys_generic.c:285 syscall(ffff80001d71ec00) at syscall+0x507 sys/arch/amd64/amd64/trap.c:570 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7f7ffffcbfc0, count: -10 ddb> show registers rdi 0 rsi 0x1 rbp 0xffff80001d71e560 rbx 0xffff80001d71e610 rdx 0x2 rcx 0 rax 0x1 r8 0xffffffff813801af kprintf+0x15f r9 0x1 r10 0x2 r11 0x2055b8b4eb21960f r12 0x3000000008 r13 0xffff80001d71e570 r14 0x100 r15 0x1 rip 0xffffffff811a1d68 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff80001d71e550 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb> show proc PROC (sshd) pid=132727 stat=onproc flags process=12 proc=0 pri=24, usrpri=50, nice=20 forw=0xffffffffffffffff, list=0xffff80001d718600,0xffff80001d717500 process=0xffff8000ffff8018 user=0xffff80001d719000, vmspace=0xfffffd806bc0a880 estcpu=0, cpticks=0, pctcpu=0.0 user=0, sys=0, intr=0 ddb> ps PID TID PPID UID S FLAGS WAIT COMMAND 75921 79878 4785 0 3 0x80 nanosleep syz-executor.0 75921 235152 4785 0 3 0x4000080 msgwait syz-executor.0 75921 307565 4785 0 3 0x4000080 fsleep syz-executor.0 4785 59275 81480 0 3 0x82 nanosleep syz-executor.0 82430 437525 81480 0 2 0x2 syz-executor.1 81480 54853 82732 0 3 0x82 thrsleep syz-fuzzer 81480 404074 82732 0 2 0x4000002 syz-fuzzer 81480 384690 82732 0 3 0x4000082 thrsleep syz-fuzzer 81480 366153 82732 0 3 0x4000082 thrsleep syz-fuzzer 81480 225185 82732 0 2 0x4000002 syz-fuzzer 81480 357154 82732 0 3 0x4000082 thrsleep syz-fuzzer 81480 87644 82732 0 3 0x4000082 thrsleep syz-fuzzer 82732 306342 23782 0 3 0x10008a pause ksh *23782 132727 15803 0 7 0x12 sshd 59873 53352 1 0 3 0x100083 ttyin getty 15803 411044 1 0 3 0x80 select sshd 79825 439478 21038 73 3 0x100090 kqread syslogd 21038 427491 1 0 3 0x100082 netio syslogd 84996 365442 1 77 3 0x100090 poll dhclient 97875 275980 1 0 3 0x80 poll dhclient 17912 486272 0 0 3 0x14200 bored smr 74015 139459 0 0 2 0x14200 zerothread 17415 11739 0 0 3 0x14200 aiodoned aiodoned 54354 212539 0 0 3 0x14200 syncer update 75980 134106 0 0 3 0x14200 cleaner cleaner 72092 95814 0 0 3 0x14200 reaper reaper 97595 159089 0 0 3 0x14200 pgdaemon pagedaemon 73489 389959 0 0 3 0x14200 bored crynlk 50375 265101 0 0 3 0x14200 bored crypto 50180 462024 0 0 3 0x40014200 acpi0 acpi0 90116 149342 0 0 3 0x14200 bored softnet 61808 181216 0 0 3 0x14200 bored systqmp 72424 46967 0 0 3 0x14200 bored systq 41645 359957 0 0 3 0x40014200 bored softclock 38413 148360 0 0 3 0x40014200 idle0 1 59741 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 9450 6324K 6324K 78643K 10549 0 pcb 13 8K 8K 78643K 13 0 rtable 105 3K 3K 78643K 190 0 ifaddr 39 10K 10K 78643K 41 0 counters 21 16K 16K 78643K 21 0 ioctlops 0 0K 2K 78643K 15 0 mount 1 1K 1K 78643K 1 0 vnodes 1216 76K 76K 78643K 1221 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 2 0K 0K 78643K 2 0 dirhash 12 2K 2K 78643K 12 0 ACPI 1809 195K 288K 78643K 12938 0 file desc 5 13K 25K 78643K 38 0 proc 47 38K 63K 78643K 358 0 subproc 32 2K 2K 78643K 34 0 NFS srvsock 1 0K 0K 78643K 1 0 NFS daemon 1 16K 16K 78643K 1 0 in_multi 33 2K 2K 78643K 33 0 ether_multi 1 0K 0K 78643K 1 0 ISOFS mount 1 32K 32K 78643K 1 0 MSDOSFS mount 1 16K 16K 78643K 1 0 ttys 31 148K 148K 78643K 31 0 exec 0 0K 1K 78643K 181 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 119 22K 23K 78643K 949 0 UVM aobj 2 2K 2K 78643K 2 0 memdesc 1 4K 4K 78643K 1 0 crypto data 1 1K 1K 78643K 1 0 NDP 9 0K 0K 78643K 9 0 temp 62 3839K 3903K 78643K 1770 0 kqueue 3 4K 4K 78643K 3 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 19 0 17 1 0 1 1 0 8 0 rtentry 112 45 0 1 2 0 2 2 0 8 0 unpcb 120 27 0 19 1 0 1 1 0 8 0 syncache 264 4 0 4 1 1 0 1 0 8 0 tcpqe 32 213 0 213 1 0 1 1 0 8 1 tcpcb 544 10 0 6 1 0 1 1 0 8 0 inpcb 296 35 0 27 1 0 1 1 0 8 0 nd6 48 6 0 0 1 0 1 1 0 8 0 art_heap8 4096 1 0 0 1 0 1 1 0 8 0 art_heap4 256 187 0 0 12 0 12 12 0 8 0 art_table 32 188 0 0 2 0 2 2 0 8 0 art_node 16 44 0 4 1 0 1 1 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino2pl 256 1422 0 24 88 0 88 88 0 8 0 ffsino 240 1422 0 24 83 0 83 83 0 8 0 nchpl 144 1653 0 46 60 0 60 60 0 8 0 uvmvnodes 72 1465 0 0 27 0 27 27 0 8 0 vnodes 208 1465 0 0 78 0 78 78 0 8 0 namei 1024 4056 0 4056 1 0 1 1 0 8 1 scxspl 192 4614 0 4614 1 0 1 1 0 8 1 plimitpl 152 14 0 7 1 0 1 1 0 8 0 sigapl 424 224 0 196 4 0 4 4 0 8 0 futexpl 56 117 0 116 1 0 1 1 0 8 0 knotepl 112 61 0 42 1 0 1 1 0 8 0 kqueuepl 144 2 0 0 1 0 1 1 0 8 0 pipelkpl 16 72 0 62 1 0 1 1 0 8 0 pipepl 120 144 0 125 1 0 1 1 0 8 0 fdescpl 432 210 0 196 2 0 2 2 0 8 0 filepl 120 1027 0 931 4 0 4 4 0 8 1 lockfpl 104 5 0 4 1 0 1 1 0 8 0 lockfspl 48 3 0 2 1 0 1 1 0 8 0 sessionpl 112 17 0 7 1 0 1 1 0 8 0 pgrppl 48 19 0 9 1 0 1 1 0 8 0 ucredpl 96 54 0 47 1 0 1 1 0 8 0 zombiepl 144 196 0 196 1 0 1 1 0 8 1 processpl 920 224 0 196 4 0 4 4 0 8 0 procpl 624 235 0 199 3 0 3 3 0 8 0 sockpl 400 81 0 63 3 0 3 3 0 8 1 mcl4k 4096 9 0 9 2 1 1 1 0 8 1 mcl2k 2048 73923 0 73870 23 8 15 19 0 8 5 mtagpl 96 2 0 2 1 1 0 1 0 8 0 mbufpl 256 117128 0 116994 14 2 12 12 0 8 3 bufpl 280 3280 0 127 226 0 226 226 0 8 0 anonpl 16 37060 0 22473 60 1 59 59 0 107 0 amapchunkpl 152 1042 0 908 8 0 8 8 0 158 1 amappl16 192 935 0 146 41 0 41 41 0 8 0 amappl15 184 5 0 2 1 0 1 1 0 8 0 amappl14 176 22 0 18 1 0 1 1 0 8 0 amappl13 168 26 0 23 1 0 1 1 0 8 0 amappl12 160 13 0 11 1 0 1 1 0 8 0 amappl11 152 48 0 37 1 0 1 1 0 8 0 amappl10 144 16 0 11 1 0 1 1 0 8 0 amappl9 136 368 0 367 1 0 1 1 0 8 0 amappl8 128 309 0 275 2 0 2 2 0 8 0 amappl7 120 106 0 94 1 0 1 1 0 8 0 amappl6 112 29 0 24 1 0 1 1 0 8 0 amappl5 104 154 0 143 1 0 1 1 0 8 0 amappl4 96 418 0 394 1 0 1 1 0 8 0 amappl3 88 100 0 94 1 0 1 1 0 8 0 amappl2 80 834 0 767 2 0 2 2 0 8 0 amappl1 72 13743 0 13327 23 6 17 17 0 8 8 amappl 80 483 0 441 1 0 1 1 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 1 0 0 1 0 1 1 0 8 0 uaddrrnd 24 210 0 196 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 210 0 196 1 0 1 1 0 8 0 vmmpekpl 168 5692 0 5666 2 0 2 2 0 8 0 vmmpepl 168 32804 0 30942 151 5 146 146 0 357 61 vmsppl 272 209 0 196 2 0 2 2 0 8 1 pdppl 4096 426 0 392 6 0 6 6 0 8 1 pvpl 32 124258 0 106735 145 0 145 145 0 265 2 pmappl 200 209 0 196 1 0 1 1 0 8 0 extentpl 40 53 0 36 1 0 1 1 0 8 0 phpool 112 244 0 13 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(ffffffff823b0c02) at panic+0x15c sys/kern/subr_prf.c:207 m_copym(fffffd80594c5f00,35c,19c,2) at m_copym+0x553 sys/kern/uipc_mbuf.c:695 tcp_output(ffff800000ac0760) at tcp_output+0x154d sys/netinet/tcp_output.c:673 tcp_usrreq(fffffd805da687d8,9,fffffd80594c5e00,0,0,ffff80001d717280) at tcp_usrreq+0xa54 sosend(fffffd805da687d8,0,ffff80001d71ea98,0,0,80) at sosend+0x669 sys/kern/uipc_socket.c:555 dofilewritev(ffff80001d717280,4,ffff80001d71ea98,0,ffff80001d71eb80) at dofilewritev+0x1ab sys/kern/sys_generic.c:365 sys_write(ffff80001d717280,ffff80001d71eb30,ffff80001d71eb80) at sys_write+0x83 sys/kern/sys_generic.c:285 syscall(ffff80001d71ec00) at syscall+0x507 sys/arch/amd64/amd64/trap.c:570 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7f7ffffcbfc0, 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(ffffffff823b0c02) at panic+0x15c sys/kern/subr_prf.c:207 m_copym(fffffd80594c5f00,35c,19c,2) at m_copym+0x553 sys/kern/uipc_mbuf.c:695 tcp_output(ffff800000ac0760) at tcp_output+0x154d sys/netinet/tcp_output.c:673 tcp_usrreq(fffffd805da687d8,9,fffffd80594c5e00,0,0,ffff80001d717280) at tcp_usrreq+0xa54 sosend(fffffd805da687d8,0,ffff80001d71ea98,0,0,80) at sosend+0x669 sys/kern/uipc_socket.c:555 dofilewritev(ffff80001d717280,4,ffff80001d71ea98,0,ffff80001d71eb80) at dofilewritev+0x1ab sys/kern/sys_generic.c:365 sys_write(ffff80001d717280,ffff80001d71eb30,ffff80001d71eb80) at sys_write+0x83 sys/kern/sys_generic.c:285 syscall(ffff80001d71ec00) at syscall+0x507 sys/arch/amd64/amd64/trap.c:570 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7f7ffffcbfc0, count: -10