panic: m_copym0: short mbuf chain Stopped at db_enter+0x18: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND *130681 16306 0 0x12 0 0 sshd db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:398 panic(ffffffff823b2f1b) at panic+0x15c sys/kern/subr_prf.c:207 m_copym(fffffd8053339f00,30c,19c,2) at m_copym+0x553 sys/kern/uipc_mbuf.c:695 tcp_output(ffff800000ac0980) at tcp_output+0x154d sys/netinet/tcp_output.c:673 tcp_usrreq(fffffd805da6d7d8,9,fffffd8053339e00,0,0,ffff80001d717c40) at tcp_usrreq+0xa54 sosend(fffffd805da6d7d8,0,ffff80001d6ca798,0,0,80) at sosend+0x669 sys/kern/uipc_socket.c:549 dofilewritev(ffff80001d717c40,4,ffff80001d6ca798,0,ffff80001d6ca880) at dofilewritev+0x1ab sys/kern/sys_generic.c:365 sys_write(ffff80001d717c40,ffff80001d6ca830,ffff80001d6ca880) at sys_write+0x83 sys/kern/sys_generic.c:285 syscall(ffff80001d6ca900) at syscall+0x507 sys/arch/amd64/amd64/trap.c:570 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7f7ffffc5990, 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(ffffffff823b2f1b) at panic+0x15c sys/kern/subr_prf.c:207 m_copym(fffffd8053339f00,30c,19c,2) at m_copym+0x553 sys/kern/uipc_mbuf.c:695 tcp_output(ffff800000ac0980) at tcp_output+0x154d sys/netinet/tcp_output.c:673 tcp_usrreq(fffffd805da6d7d8,9,fffffd8053339e00,0,0,ffff80001d717c40) at tcp_usrreq+0xa54 sosend(fffffd805da6d7d8,0,ffff80001d6ca798,0,0,80) at sosend+0x669 sys/kern/uipc_socket.c:549 dofilewritev(ffff80001d717c40,4,ffff80001d6ca798,0,ffff80001d6ca880) at dofilewritev+0x1ab sys/kern/sys_generic.c:365 sys_write(ffff80001d717c40,ffff80001d6ca830,ffff80001d6ca880) at sys_write+0x83 sys/kern/sys_generic.c:285 syscall(ffff80001d6ca900) at syscall+0x507 sys/arch/amd64/amd64/trap.c:570 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7f7ffffc5990, count: -10 ddb> show registers rdi 0 rsi 0x1 rbp 0xffff80001d6ca260 rbx 0xffff80001d6ca310 rdx 0x2 rcx 0 rax 0x1 r8 0xffffffff8233c15f kprintf+0x15f r9 0x1 r10 0x2 r11 0xed789bf68dbc1b96 r12 0x3000000008 r13 0xffff80001d6ca270 r14 0x100 r15 0x1 rip 0xffffffff81dc0218 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff80001d6ca250 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb> show proc PROC (sshd) pid=130681 stat=onproc flags process=12 proc=0 pri=24, usrpri=50, nice=20 forw=0xffffffffffffffff, list=0xffff80001d718600,0xffff80001d717770 process=0xffff8000ffff8748 user=0xffff80001d6c5000, vmspace=0xfffffd806bc09110 estcpu=0, cpticks=0, pctcpu=0.0 user=0, sys=0, intr=0 ddb> ps PID TID PPID UID S FLAGS WAIT COMMAND 47393 434221 0 0 3 0x14280 nfsidl nfsio 13926 102366 0 0 3 0x14280 nfsidl nfsio 88723 84152 0 0 3 0x14280 nfsidl nfsio 91453 447037 0 0 3 0x14280 nfsidl nfsio 4657 50695 0 0 3 0x14280 nfsidl nfsio 44344 242638 0 0 3 0x14280 nfsidl nfsio 72114 418041 0 0 3 0x14280 nfsidl nfsio 49888 195082 0 0 3 0x14280 nfsidl nfsio 49237 297096 0 0 3 0x14280 nfsidl nfsio 91122 23025 0 0 3 0x14280 nfsidl nfsio 58612 44410 0 0 3 0x14280 nfsidl nfsio 56895 323780 0 0 3 0x14280 nfsidl nfsio 88337 279862 0 0 3 0x14280 nfsidl nfsio 61252 363319 0 0 3 0x14280 nfsidl nfsio 31000 12134 0 0 3 0x14280 nfsidl nfsio 58956 166810 0 0 3 0x14280 nfsidl nfsio 85594 379423 0 0 3 0x14280 nfsidl nfsio 10334 506125 0 0 3 0x14280 nfsidl nfsio 73718 426479 0 0 3 0x14280 nfsidl nfsio 185 62329 0 0 3 0x14280 nfsidl nfsio 89538 342883 79175 0 3 0x82 piperd syz-executor.0 61602 372934 0 0 3 0x14200 acct acct 88960 418005 0 0 3 0x14200 bored sosplice 4378 440749 79175 0 2 0x2 syz-executor.1 79175 483006 10026 0 2 0x2 syz-fuzzer 79175 110409 10026 0 2 0x4000002 syz-fuzzer 79175 158099 10026 0 3 0x4000082 thrsleep syz-fuzzer 79175 130513 10026 0 3 0x4000082 thrsleep syz-fuzzer 79175 284599 10026 0 3 0x4000082 thrsleep syz-fuzzer 79175 65749 10026 0 3 0x4000082 thrsleep syz-fuzzer 79175 475750 10026 0 3 0x4000082 thrsleep syz-fuzzer 79175 408769 10026 0 3 0x4000082 thrsleep syz-fuzzer 10026 240754 16306 0 3 0x10008a pause ksh *16306 130681 93855 0 7 0x12 sshd 13241 351669 1 0 3 0x100083 ttyin getty 93855 501754 1 0 3 0x80 select sshd 39815 368478 57509 73 3 0x100090 kqread syslogd 57509 150048 1 0 3 0x100082 netio syslogd 81695 234866 1 77 3 0x100090 poll dhclient 3774 238637 1 0 3 0x80 poll dhclient 17195 370034 0 0 3 0x14200 bored smr 32414 39326 0 0 2 0x14200 zerothread 9666 344816 0 0 3 0x14200 aiodoned aiodoned 39595 245315 0 0 3 0x14200 syncer update 49898 334590 0 0 3 0x14200 cleaner cleaner 66011 331149 0 0 3 0x14200 reaper reaper 23057 457022 0 0 3 0x14200 pgdaemon pagedaemon 89624 229000 0 0 3 0x14200 bored crynlk 23416 368031 0 0 3 0x14200 bored crypto 2572 405709 0 0 3 0x40014200 acpi0 acpi0 31453 262211 0 0 3 0x14200 bored softnet 18696 151460 0 0 3 0x14200 bored systqmp 88046 244245 0 0 3 0x14200 bored systq 85428 344153 0 0 3 0x40014200 bored softclock 97317 431251 0 0 3 0x40014200 idle0 1 219755 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 9519 6350K 6801K 78643K 11527 0 pcb 13 8K 8K 78643K 119 0 rtable 150 13K 15K 78643K 668 0 ifaddr 113 23K 24K 78643K 279 0 sysctl 2 0K 0K 78643K 2 0 counters 21 16K 16K 78643K 39 0 ioctlops 0 0K 4K 78643K 118 0 iov 0 0K 18K 78643K 1013 0 mount 1 1K 1K 78643K 1 0 vnodes 1221 77K 77K 78643K 1541 0 UFS quota 1 32K 32K 78643K 1 0 UFS mount 5 36K 36K 78643K 5 0 shm 2 1K 5K 78643K 13 0 VM map 2 0K 0K 78643K 2 0 sem 12 1K 1K 78643K 59 0 dirhash 12 2K 2K 78643K 12 0 ACPI 1809 195K 288K 78643K 12938 0 file desc 4 9K 25K 78643K 705 0 sigio 0 0K 0K 78643K 10 0 proc 50 38K 63K 78643K 467 0 subproc 32 2K 2K 78643K 55 0 NFS srvsock 1 0K 0K 78643K 1 0 NFS daemon 1 16K 16K 78643K 1 0 ip_moptions 0 0K 0K 78643K 45 0 in_multi 118 5K 5K 78643K 208 0 ether_multi 1 0K 0K 78643K 14 0 mrt 0 0K 0K 78643K 4 0 ISOFS mount 1 32K 32K 78643K 1 0 MSDOSFS mount 1 16K 16K 78643K 1 0 ttys 49 228K 228K 78643K 49 0 exec 0 0K 1K 78643K 252 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 148 89K 104K 78643K 2466 0 UVM aobj 34 2K 2K 78643K 38 0 memdesc 1 4K 4K 78643K 1 0 crypto data 1 1K 1K 78643K 1 0 ip6_options 0 0K 0K 78643K 100 0 NDP 14 0K 0K 78643K 44 0 temp 145 3866K 3944K 78643K 11695 0 kqueue 3 4K 10K 78643K 34 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 11 0 3 1 0 1 1 0 8 0 rtpcb 80 63 0 61 1 0 1 1 0 8 0 rtentry 112 79 0 34 2 0 2 2 0 8 0 unpcb 120 220 0 211 1 0 1 1 0 8 0 syncache 264 9 0 9 2 2 0 1 0 8 0 tcpqe 32 171 0 171 2 2 0 1 0 8 0 tcpcb 544 240 0 236 1 0 1 1 0 8 0 ipq 40 6 0 6 2 2 0 1 0 8 0 ipqe 40 16 0 16 2 2 0 1 0 8 0 inpcb 280 719 0 711 3 1 2 2 0 8 1 rttmr 72 2 0 2 2 2 0 1 0 8 0 ip6q 72 2 0 2 1 1 0 1 0 8 0 ip6af 40 6 0 6 1 1 0 1 0 8 0 nd6 48 16 0 11 1 0 1 1 0 8 0 pkpcb 40 2 0 2 1 1 0 1 0 8 0 ppxss 1128 3 0 3 2 2 0 1 0 8 0 pfstscr 40 1 0 0 1 0 1 1 0 8 0 pfosfp 40 1 0 0 1 0 1 1 0 8 0 pfosfpen 112 1 0 0 1 0 1 1 0 8 0 pfrke_plain 160 4 0 0 1 0 1 1 0 8 0 pfrktable 1344 118 0 100 2 0 2 2 0 8 0 pftag 88 20 0 14 1 0 1 1 0 8 0 pfstitem 24 3 0 0 1 0 1 1 0 8 0 pfstkey 112 3 0 0 1 0 1 1 0 8 0 pfstate 328 2 0 0 1 0 1 1 0 8 0 pfrule 1360 42 0 20 2 0 2 2 0 8 0 art_heap8 4096 2 0 0 2 0 2 2 0 8 0 art_heap4 256 329 0 116 16 2 14 14 0 8 0 art_table 32 331 0 116 2 0 2 2 0 8 0 art_node 16 78 0 36 1 0 1 1 0 8 0 sysvmsgpl 40 46 0 13 1 0 1 1 0 8 0 semupl 112 2 0 2 1 1 0 1 0 8 0 semapl 112 55 0 45 1 0 1 1 0 8 0 shmpl 112 36 0 4 1 0 1 1 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino2pl 256 2363 0 968 88 0 88 88 0 8 0 ffsino 240 2363 0 968 83 0 83 83 0 8 0 nchpl 144 3923 0 2336 60 0 60 60 0 8 0 rtmask 32 8 0 4 1 0 1 1 0 8 0 uvmvnodes 72 2622 0 0 48 0 48 48 0 8 0 vnodes 208 2622 0 0 138 0 138 138 0 8 0 namei 1024 10914 0 10914 1 0 1 1 0 8 1 vcpupl 1984 10 0 0 2 0 2 2 0 8 0 vmpool 528 12 0 2 1 0 1 1 0 8 0 pfiaddrpl 120 54 0 30 1 0 1 1 0 8 0 scsiplug 64 2 0 2 1 1 0 1 0 8 0 scxspl 192 11316 0 11316 1 0 1 1 0 8 1 plimitpl 152 61 0 54 1 0 1 1 0 8 0 sigapl 424 910 0 861 6 0 6 6 0 8 0 futexpl 56 13879 0 13879 1 0 1 1 0 8 1 knotepl 112 102 0 83 1 0 1 1 0 8 0 kqueuepl 144 89 0 87 1 0 1 1 0 8 0 pipelkpl 16 205 0 195 1 0 1 1 0 8 0 pipepl 120 410 0 391 2 1 1 2 0 8 0 fdescpl 432 874 0 861 2 0 2 2 0 8 0 filepl 120 5714 0 5619 5 1 4 5 0 8 1 lockfpl 104 196 0 195 1 0 1 1 0 8 0 lockfspl 48 61 0 60 1 0 1 1 0 8 0 sessionpl 112 18 0 8 1 0 1 1 0 8 0 pgrppl 48 26 0 16 1 0 1 1 0 8 0 ucredpl 96 602 0 595 1 0 1 1 0 8 0 zombiepl 144 861 0 861 1 0 1 1 0 8 1 processpl 920 910 0 861 7 0 7 7 0 8 0 procpl 624 1682 0 1626 5 0 5 5 0 8 0 sosppl 128 11 0 11 3 3 0 1 0 8 0 sockpl 400 1005 0 987 5 1 4 4 0 8 1 mcl64k 65536 320 0 320 33 24 9 33 0 8 9 mcl16k 16384 11 0 11 2 1 1 1 0 8 1 mcl12k 12288 27 0 27 2 1 1 1 0 8 1 mcl9k 9216 7 0 7 2 1 1 1 0 8 1 mcl8k 8192 29 0 29 1 0 1 1 0 8 1 mcl4k 4096 70 0 70 2 1 1 1 0 8 1 mcl2k2 2112 4 0 4 2 1 1 1 0 8 1 mcl2k 2048 78246 0 78199 17 10 7 15 0 8 0 mtagpl 80 59 0 30 2 1 1 1 0 8 0 mbufpl 256 128407 0 128194 30 12 18 27 0 8 4 bufpl 280 5127 0 144 356 0 356 356 0 8 0 anonpl 16 108754 0 91961 100 20 80 98 0 107 7 amapchunkpl 152 4703 0 4576 25 6 19 19 0 158 12 amappl16 192 4933 0 3983 74 19 55 66 0 8 5 amappl15 184 20 0 18 1 0 1 1 0 8 0 amappl14 176 183 0 176 1 0 1 1 0 8 0 amappl13 168 34 0 31 1 0 1 1 0 8 0 amappl12 160 523 0 522 2 1 1 1 0 8 0 amappl11 152 57 0 46 1 0 1 1 0 8 0 amappl10 144 15 0 10 1 0 1 1 0 8 0 amappl9 136 508 0 505 1 0 1 1 0 8 0 amappl8 128 510 0 462 2 0 2 2 0 8 0 amappl7 120 113 0 101 1 0 1 1 0 8 0 amappl6 112 22 0 18 1 0 1 1 0 8 0 amappl5 104 1140 0 1129 1 0 1 1 0 8 0 amappl4 96 452 0 425 1 0 1 1 0 8 0 amappl3 88 133 0 128 1 0 1 1 0 8 0 amappl2 80 6065 0 6008 2 0 2 2 0 8 0 amappl1 72 24139 0 23741 24 15 9 17 0 8 0 amappl 80 1918 0 1876 3 1 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 37 0 4 1 0 1 1 0 8 0 uaddrrnd 24 886 0 863 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 886 0 863 1 0 1 1 0 8 0 vmmpekpl 168 8885 0 8848 2 0 2 2 0 8 0 vmmpepl 168 108895 0 106921 134 23 111 122 0 357 15 vmsppl 272 885 0 863 2 0 2 2 0 8 0 pdppl 4096 1778 0 1736 8 2 6 6 0 8 0 pvpl 32 290643 0 271860 224 18 206 224 0 265 49 pmappl 200 885 0 863 2 0 2 2 0 8 0 extentpl 40 53 0 36 1 0 1 1 0 8 0 phpool 112 303 0 55 8 0 8 8 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(ffffffff823b2f1b) at panic+0x15c sys/kern/subr_prf.c:207 m_copym(fffffd8053339f00,30c,19c,2) at m_copym+0x553 sys/kern/uipc_mbuf.c:695 tcp_output(ffff800000ac0980) at tcp_output+0x154d sys/netinet/tcp_output.c:673 tcp_usrreq(fffffd805da6d7d8,9,fffffd8053339e00,0,0,ffff80001d717c40) at tcp_usrreq+0xa54 sosend(fffffd805da6d7d8,0,ffff80001d6ca798,0,0,80) at sosend+0x669 sys/kern/uipc_socket.c:549 dofilewritev(ffff80001d717c40,4,ffff80001d6ca798,0,ffff80001d6ca880) at dofilewritev+0x1ab sys/kern/sys_generic.c:365 sys_write(ffff80001d717c40,ffff80001d6ca830,ffff80001d6ca880) at sys_write+0x83 sys/kern/sys_generic.c:285 syscall(ffff80001d6ca900) at syscall+0x507 sys/arch/amd64/amd64/trap.c:570 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7f7ffffc5990, 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(ffffffff823b2f1b) at panic+0x15c sys/kern/subr_prf.c:207 m_copym(fffffd8053339f00,30c,19c,2) at m_copym+0x553 sys/kern/uipc_mbuf.c:695 tcp_output(ffff800000ac0980) at tcp_output+0x154d sys/netinet/tcp_output.c:673 tcp_usrreq(fffffd805da6d7d8,9,fffffd8053339e00,0,0,ffff80001d717c40) at tcp_usrreq+0xa54 sosend(fffffd805da6d7d8,0,ffff80001d6ca798,0,0,80) at sosend+0x669 sys/kern/uipc_socket.c:549 dofilewritev(ffff80001d717c40,4,ffff80001d6ca798,0,ffff80001d6ca880) at dofilewritev+0x1ab sys/kern/sys_generic.c:365 sys_write(ffff80001d717c40,ffff80001d6ca830,ffff80001d6ca880) at sys_write+0x83 sys/kern/sys_generic.c:285 syscall(ffff80001d6ca900) at syscall+0x507 sys/arch/amd64/amd64/trap.c:570 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7f7ffffc5990, count: -10