panic: m_copym0: short mbuf chain Stopped at db_enter+0x18: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND *367216 9181 0 0x12 0 0 sshd db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:398 panic() at panic+0x15c sys/kern/subr_prf.c:207 m_copym(fffffd80343bc200,2ec,1fc,2) at m_copym+0x553 sys/kern/uipc_mbuf.c:695 tcp_output(ffff800000a63100) at tcp_output+0x14d6 sys/netinet/tcp_output.c:673 tcp_usrreq(fffffd80363e0188,9,fffffd80343bc100,0,0,ffff8000ffff4778) at tcp_usrreq+0xa54 sosend(fffffd80363e0188,0,ffff800014866ca8,0,0,80) at sosend+0x63d sys/kern/uipc_socket.c:524 dofilewritev(ffff8000ffff4778,4,ffff800014866ca8,0,ffff800014866d90) at dofilewritev+0x1ac sys/kern/sys_generic.c:364 sys_write(ffff8000ffff4778,ffff800014866d40,ffff800014866d90) at sys_write+0x83 sys/kern/sys_generic.c:284 syscall(ffff800014866e10) at syscall+0x507 sys/arch/amd64/amd64/trap.c:555 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7f7ffffca1d0, 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() at panic+0x15c sys/kern/subr_prf.c:207 m_copym(fffffd80343bc200,2ec,1fc,2) at m_copym+0x553 sys/kern/uipc_mbuf.c:695 tcp_output(ffff800000a63100) at tcp_output+0x14d6 sys/netinet/tcp_output.c:673 tcp_usrreq(fffffd80363e0188,9,fffffd80343bc100,0,0,ffff8000ffff4778) at tcp_usrreq+0xa54 sosend(fffffd80363e0188,0,ffff800014866ca8,0,0,80) at sosend+0x63d sys/kern/uipc_socket.c:524 dofilewritev(ffff8000ffff4778,4,ffff800014866ca8,0,ffff800014866d90) at dofilewritev+0x1ac sys/kern/sys_generic.c:364 sys_write(ffff8000ffff4778,ffff800014866d40,ffff800014866d90) at sys_write+0x83 sys/kern/sys_generic.c:284 syscall(ffff800014866e10) at syscall+0x507 sys/arch/amd64/amd64/trap.c:555 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7f7ffffca1d0, count: -10 ddb> show registers rdi 0 rsi 0x1 rbp 0xffff800014866790 rbx 0xffff800014866840 rdx 0x2 rcx 0 rax 0 r8 0xffff800014866750 r9 0x1 r10 0 r11 0xe7954a75767b1bca r12 0x3000000008 r13 0xffff8000148667a0 r14 0x100 r15 0x1 rip 0xffffffff81d84668 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff800014866780 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb> show proc PROC (sshd) pid=367216 stat=onproc flags process=12 proc=0 pri=50, usrpri=50, nice=20 forw=0xffffffffffffffff, list=0xffff8000ffff4500,0xffff8000ffff4020 process=0xffff8000148a37b8 user=0xffff800014861000, vmspace=0xfffffd803f011aa0 estcpu=0, cpticks=0, pctcpu=0.0 user=0, sys=0, intr=0 ddb> ps PID TID PPID UID S FLAGS WAIT COMMAND 29777 360436 98942 0 2 0 syz-executor.1 98942 437757 96452 0 3 0x82 nanosleep syz-executor.1 57097 192317 96452 0 2 0x2 syz-executor.0 48813 255266 0 0 3 0x14200 acct acct 57178 414002 1 0 3 0x100083 ttyin getty 1722 513753 0 0 3 0x14200 bored sosplice 96452 431508 95097 0 3 0x82 thrsleep syz-fuzzer 96452 227837 95097 0 3 0x4000082 nanosleep syz-fuzzer 96452 78697 95097 0 3 0x4000082 thrsleep syz-fuzzer 96452 53195 95097 0 3 0x4000082 thrsleep syz-fuzzer 96452 497632 95097 0 3 0x4000082 thrsleep syz-fuzzer 96452 124685 95097 0 3 0x4000082 thrsleep syz-fuzzer 96452 374851 95097 0 3 0x4000082 thrsleep syz-fuzzer 96452 440511 95097 0 2 0x4000002 syz-fuzzer 95097 179200 9181 0 3 0x10008a pause ksh * 9181 367216 32745 0 7 0x12 sshd 32745 373589 1 0 3 0x80 select sshd 64087 220575 73945 73 3 0x100090 kqread syslogd 73945 299172 1 0 3 0x100082 netio syslogd 72693 356776 0 0 2 0x14200 zerothread 78977 390049 0 0 3 0x14200 aiodoned aiodoned 75495 413549 0 0 3 0x14200 syncer update 5831 211104 0 0 3 0x14200 cleaner cleaner 9332 423137 0 0 3 0x14200 reaper reaper 67183 519531 0 0 3 0x14200 pgdaemon pagedaemon 66415 370525 0 0 3 0x14200 bored crynlk 4241 87967 0 0 3 0x14200 bored crypto 76763 119533 0 0 3 0x40014200 acpi0 acpi0 34668 153588 0 0 3 0x14200 bored softnet 96831 339984 0 0 3 0x14200 bored systqmp 350 113171 0 0 3 0x14200 bored systq 35666 36365 0 0 3 0x40014200 bored softclock 72920 46059 0 0 3 0x40014200 idle0 86299 60848 0 0 3 0x14200 bored smr 1 118092 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 Kern Lim devbuf 9588 6582K 8448K 78643K 35495 0 0 pcb 13 10K 12K 78643K 1040 0 0 rtable 115 4K 4K 78643K 2185 0 0 ifaddr 279 32K 33K 78643K 1062 0 0 counters 19 16K 16K 78643K 19 0 0 ioctlops 0 0K 2K 78643K 263 0 0 iov 0 0K 32K 78643K 1057 0 0 mount 1 1K 1K 78643K 1 0 0 vnodes 1230 77K 78K 78643K 8419 0 0 UFS quota 1 32K 32K 78643K 1 0 0 UFS mount 5 36K 36K 78643K 5 0 0 shm 2 1K 5K 78643K 81 0 0 VM map 45 11K 11K 78643K 65 0 0 sem 12 0K 1K 78643K 1236 0 0 dirhash 12 2K 2K 78643K 12 0 0 ACPI 1794 195K 288K 78643K 12646 0 0 file desc 5 13K 25K 78643K 4169 0 0 sigio 0 0K 0K 78643K 106 0 0 proc 44 30K 63K 78643K 1703 0 0 subproc 32 2K 2K 78643K 461 0 0 NFS srvsock 1 0K 0K 78643K 1 0 0 NFS daemon 1 16K 16K 78643K 1 0 0 ip_moptions 0 0K 0K 78643K 1925 0 0 in_multi 116 6K 7K 78643K 674 0 0 ether_multi 1 0K 0K 78643K 46 0 0 mrt 1 0K 0K 78643K 35 0 0 ISOFS mount 1 32K 32K 78643K 1 0 0 MSDOSFS mount 1 16K 16K 78643K 1 0 0 ttys 120 530K 530K 78643K 120 0 0 exec 0 0K 1K 78643K 969 0 0 pagedep 1 8K 8K 78643K 1 0 0 inodedep 1 32K 32K 78643K 1 0 0 newblk 1 0K 0K 78643K 1 0 0 VM swap 7 26K 26K 78643K 7 0 0 UVM amap 168 317K 318K 78643K 11579 0 0 UVM aobj 130 6K 6K 78643K 140 0 0 memdesc 1 4K 4K 78643K 1 0 0 crypto data 1 1K 1K 78643K 1 0 0 ip6_options 0 0K 1K 78643K 1069 0 0 NDP 20 0K 1K 78643K 258 0 0 temp 166 3535K 3611K 78643K 175431 0 0 kqueue 0 0K 0K 78643K 47 0 0 SYN cache 2 16K 16K 78643K 2 0 0 ddb> show all pools Name Size Requests Fail Releases Pgreq Pgrel Npage Hiwat Minpg Maxpg Idle arp 64 110 0 105 1 0 1 1 0 8 0 rtpcb 80 1481 0 1481 1 1 0 1 0 8 0 rtentry 112 502 0 459 2 0 2 2 0 8 0 unpcb 120 2873 0 2865 1 0 1 1 0 8 0 syncache 264 19 0 19 11 11 0 1 0 8 0 tcpqe 32 33 0 33 8 8 0 1 0 8 0 tcpcb 544 3210 0 3206 54 53 1 15 0 8 0 ipq 40 88 0 88 14 14 0 1 0 8 0 ipqe 40 2759 0 2759 14 14 0 1 0 8 0 inpcb 280 7112 0 7108 37 36 1 9 0 8 0 rttmr 72 7 0 7 5 5 0 1 0 8 0 nd6 48 69 0 65 1 0 1 1 0 8 0 pkpcb 40 14 0 14 8 8 0 1 0 8 0 swfcl 56 4 0 0 1 0 1 1 0 8 0 ppxss 1128 93 0 93 19 18 1 1 0 8 1 art_heap8 4096 1 0 0 1 0 1 1 0 8 0 art_heap4 256 2072 0 1849 28 14 14 15 0 8 0 art_table 32 2073 0 1849 2 0 2 2 0 8 0 art_node 16 501 0 462 1 0 1 1 0 8 0 sysvmsgpl 40 63 0 50 1 0 1 1 0 8 0 semupl 112 1 0 1 1 1 0 1 0 8 0 semapl 112 1234 0 1224 1 0 1 1 0 8 0 shmpl 112 138 0 10 4 0 4 4 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino1pl 128 7925 0 6524 46 0 46 46 0 8 0 ffsino 240 7925 0 6524 83 0 83 83 0 8 0 nchpl 144 15692 0 15258 60 40 20 60 0 8 0 uvmvnodes 72 6667 0 0 122 0 122 122 0 8 0 vnodes 208 6667 0 0 351 0 351 351 0 8 0 namei 1024 58636 0 58636 2 1 1 1 0 8 1 vcpupl 1984 43 0 0 6 0 6 6 0 8 0 vmpool 520 63 0 20 3 0 3 3 0 8 0 scsiplug 64 1 0 1 1 1 0 1 0 8 0 scxspl 192 47394 0 47394 27 26 1 7 0 8 1 plimitpl 152 394 0 388 1 0 1 1 0 8 0 sigapl 432 4265 0 4254 2 0 2 2 0 8 0 futexpl 56 140900 0 140900 2 1 1 1 0 8 1 knotepl 112 1205 0 1186 3 2 1 2 0 8 0 kqueuepl 104 1937 0 1935 10 9 1 4 0 8 0 pipepl 128 2976 0 2957 17 16 1 2 0 8 0 fdescpl 424 4266 0 4254 2 0 2 2 0 8 0 filepl 120 44968 0 44884 37 33 4 11 0 8 1 lockfpl 104 1558 0 1558 2 1 1 1 0 8 1 lockfspl 48 515 0 515 2 1 1 1 0 8 1 sessionpl 112 43 0 35 1 0 1 1 0 8 0 pgrppl 48 111 0 103 1 0 1 1 0 8 0 ucredpl 96 6607 0 6600 1 0 1 1 0 8 0 zombiepl 144 4256 0 4256 1 0 1 1 0 8 1 processpl 864 4284 0 4256 4 0 4 4 0 8 0 procpl 632 9511 0 9476 4 0 4 4 0 8 0 sosppl 128 72 0 72 14 14 0 1 0 8 0 sockpl 384 11576 0 11564 66 63 3 14 0 8 1 mcl64k 65536 766 0 766 39 38 1 32 0 8 1 mcl16k 16384 59 0 59 16 16 0 1 0 8 0 mcl12k 12288 119 0 119 17 16 1 1 0 8 1 mcl9k 9216 87 0 87 16 15 1 1 0 8 1 mcl8k 8192 262 0 262 8 7 1 1 0 8 1 mcl4k 4096 582 0 582 4 3 1 1 0 8 1 mcl2k2 2112 40 0 40 15 14 1 1 0 8 1 mcl2k 2048 71879 0 71833 19 13 6 13 0 8 0 mtagpl 80 345 0 340 4 3 1 2 0 8 0 mbufpl 256 162819 0 162718 198 190 8 45 0 8 0 bufpl 256 22670 0 15998 418 0 418 418 0 8 0 anonpl 16 589600 0 570048 222 125 97 111 0 62 0 amapchunkpl 152 23991 0 23808 77 69 8 31 0 158 0 amappl16 192 27567 0 26249 218 140 78 79 0 8 7 amappl15 184 537 0 536 1 0 1 1 0 8 0 amappl14 176 958 0 954 1 0 1 1 0 8 0 amappl13 168 260 0 260 5 5 0 1 0 8 0 amappl12 160 285 0 284 6 5 1 1 0 8 0 amappl11 152 499 0 494 1 0 1 1 0 8 0 amappl10 144 963 0 959 1 0 1 1 0 8 0 amappl9 136 1309 0 1306 1 0 1 1 0 8 0 amappl8 128 877 0 830 3 1 2 2 0 8 0 amappl7 120 1109 0 1103 1 0 1 1 0 8 0 amappl6 112 428 0 414 1 0 1 1 0 8 0 amappl5 104 643 0 636 1 0 1 1 0 8 0 amappl4 96 4049 0 4018 1 0 1 1 0 8 0 amappl3 88 1705 0 1697 1 0 1 1 0 8 0 amappl2 80 32599 0 32537 3 1 2 3 0 8 0 amappl1 72 88498 0 88130 25 16 9 20 0 8 0 amappl 80 10224 0 10168 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 64 139 0 10 3 0 3 3 0 8 0 uaddrrnd 24 4329 0 4254 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 4329 0 4254 1 0 1 1 0 8 0 vmmpekpl 168 30135 0 30098 2 0 2 2 0 8 0 vmmpepl 168 533634 0 531178 394 234 160 165 0 357 41 vmsppl 272 4265 0 4254 4 3 1 2 0 8 0 pdppl 4096 8664 0 8591 11 1 10 10 0 8 0 pvpl 32 1578311 0 1557733 473 255 218 303 0 265 14 pmappl 200 4328 0 4274 3 0 3 3 0 8 0 extentpl 40 46 0 29 1 0 1 1 0 8 0 phpool 112 890 0 341 17 0 17 17 0 8 0