panic: m_copym0: short mbuf chain Stopped at db_enter+0x18: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND *510349 35041 0 0x12 0 0 sshd db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:398 panic(ffffffff823c7279) at panic+0x15c sys/kern/subr_prf.c:207 m_copym(fffffd805e431800,244,144,2) at m_copym+0x553 sys/kern/uipc_mbuf.c:695 tcp_output(ffff800000ac2540) at tcp_output+0x154d sys/netinet/tcp_output.c:673 tcp_usrreq(fffffd805da6f4b8,9,fffffd805e431700,0,0,ffff80001d717010) at tcp_usrreq+0xa54 sosend(fffffd805da6f4b8,0,ffff80001d71e398,0,0,80) at sosend+0x669 sys/kern/uipc_socket.c:555 dofilewritev(ffff80001d717010,4,ffff80001d71e398,0,ffff80001d71e480) at dofilewritev+0x1ab sys/kern/sys_generic.c:365 sys_write(ffff80001d717010,ffff80001d71e430,ffff80001d71e480) at sys_write+0x83 sys/kern/sys_generic.c:285 syscall(ffff80001d71e500) at syscall+0x507 sys/arch/amd64/amd64/trap.c:570 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7f7ffffd1830, 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(ffffffff823c7279) at panic+0x15c sys/kern/subr_prf.c:207 m_copym(fffffd805e431800,244,144,2) at m_copym+0x553 sys/kern/uipc_mbuf.c:695 tcp_output(ffff800000ac2540) at tcp_output+0x154d sys/netinet/tcp_output.c:673 tcp_usrreq(fffffd805da6f4b8,9,fffffd805e431700,0,0,ffff80001d717010) at tcp_usrreq+0xa54 sosend(fffffd805da6f4b8,0,ffff80001d71e398,0,0,80) at sosend+0x669 sys/kern/uipc_socket.c:555 dofilewritev(ffff80001d717010,4,ffff80001d71e398,0,ffff80001d71e480) at dofilewritev+0x1ab sys/kern/sys_generic.c:365 sys_write(ffff80001d717010,ffff80001d71e430,ffff80001d71e480) at sys_write+0x83 sys/kern/sys_generic.c:285 syscall(ffff80001d71e500) at syscall+0x507 sys/arch/amd64/amd64/trap.c:570 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7f7ffffd1830, count: -10 ddb> show registers rdi 0 rsi 0x1 rbp 0xffff80001d71de60 rbx 0xffff80001d71df10 rdx 0x2 rcx 0 rax 0x1 r8 0xffffffff8203df2f kprintf+0x15f r9 0x1 r10 0x2 r11 0x722ec88ad9dc8db1 r12 0x3000000008 r13 0xffff80001d71de70 r14 0x100 r15 0x1 rip 0xffffffff81fb0608 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff80001d71de50 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb> show proc PROC (sshd) pid=510349 stat=onproc flags process=12 proc=0 pri=24, usrpri=50, nice=20 forw=0xffffffffffffffff, list=0xffff80001d7179d0,0xffff80001d717500 process=0xffff8000ffff8e78 user=0xffff80001d719000, vmspace=0xfffffd806bc09bb0 estcpu=0, cpticks=0, pctcpu=0.0 user=0, sys=0, intr=0 ddb> ps PID TID PPID UID S FLAGS WAIT COMMAND 70257 478105 0 0 3 0x14200 acct acct 18687 107011 67443 0 2 0x2 syz-executor.1 93445 523975 0 0 3 0x14200 bored sosplice 20176 207866 1 0 3 0x100083 ttyin getty 4751 374955 67443 0 2 0x2 syz-executor.0 67443 351294 93737 0 3 0x82 thrsleep syz-fuzzer 67443 275167 93737 0 2 0x4000002 syz-fuzzer 67443 341259 93737 0 3 0x4000082 thrsleep syz-fuzzer 67443 63050 93737 0 3 0x4000082 thrsleep syz-fuzzer 67443 433645 93737 0 3 0x4000082 thrsleep syz-fuzzer 67443 519660 93737 0 2 0x4000002 syz-fuzzer 67443 480804 93737 0 3 0x4000082 thrsleep syz-fuzzer 93737 245325 35041 0 3 0x10008a pause ksh *35041 510349 82903 0 7 0x12 sshd 82903 357092 1 0 3 0x80 select sshd 46204 109131 79612 73 3 0x100090 kqread syslogd 79612 420143 1 0 3 0x100082 netio syslogd 35700 380734 1 77 3 0x100090 poll dhclient 71702 124917 1 0 3 0x80 poll dhclient 22454 396072 0 0 3 0x14200 bored smr 24461 318544 0 0 3 0x14200 pgzero zerothread 17152 99385 0 0 3 0x14200 aiodoned aiodoned 14579 248371 0 0 3 0x14200 syncer update 31489 479042 0 0 3 0x14200 cleaner cleaner 37336 309033 0 0 3 0x14200 reaper reaper 38993 389798 0 0 3 0x14200 pgdaemon pagedaemon 30394 104554 0 0 3 0x14200 bored crynlk 75980 305887 0 0 3 0x14200 bored crypto 4622 32756 0 0 3 0x40014200 acpi0 acpi0 52301 438698 0 0 3 0x14200 bored softnet 47870 103712 0 0 3 0x14200 bored systqmp 19869 420303 0 0 3 0x14200 bored systq 72315 420834 0 0 3 0x40014200 bored softclock 17632 70293 0 0 3 0x40014200 idle0 1 231435 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 9517 6346K 6860K 78643K 11411 0 pcb 13 8K 8K 78643K 81 0 rtable 106 3K 7K 78643K 423 0 ifaddr 86 16K 16K 78643K 170 0 counters 21 16K 16K 78643K 28 0 ioctlops 0 0K 4K 78643K 78 0 iov 0 0K 16K 78643K 52 0 mount 1 1K 1K 78643K 1 0 vnodes 1221 77K 77K 78643K 1474 0 UFS quota 1 32K 32K 78643K 1 0 UFS mount 5 36K 36K 78643K 5 0 shm 2 1K 5K 78643K 10 0 VM map 2 0K 0K 78643K 2 0 sem 12 0K 1K 78643K 56 0 dirhash 12 2K 2K 78643K 12 0 ACPI 1809 195K 288K 78643K 12938 0 file desc 4 9K 25K 78643K 397 0 sigio 0 0K 0K 78643K 10 0 proc 49 38K 55K 78643K 459 0 subproc 32 2K 2K 78643K 51 0 NFS srvsock 1 0K 0K 78643K 1 0 NFS daemon 1 16K 16K 78643K 1 0 ip_moptions 0 0K 0K 78643K 102 0 in_multi 59 3K 3K 78643K 133 0 ether_multi 1 0K 0K 78643K 8 0 mrt 0 0K 0K 78643K 1 0 ISOFS mount 1 32K 32K 78643K 1 0 MSDOSFS mount 1 16K 16K 78643K 1 0 ttys 43 201K 201K 78643K 43 0 exec 0 0K 1K 78643K 219 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 127 55K 55K 78643K 1776 0 UVM aobj 31 4K 4K 78643K 32 0 memdesc 1 4K 4K 78643K 1 0 crypto data 1 1K 1K 78643K 1 0 ip6_options 0 0K 0K 78643K 54 0 NDP 14 0K 0K 78643K 34 0 temp 122 3854K 3918K 78643K 11229 0 kqueue 3 4K 12K 78643K 44 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 8 0 2 1 0 1 1 0 8 0 rtpcb 80 51 0 49 1 0 1 1 0 8 0 rtentry 112 66 0 22 2 0 2 2 0 8 0 unpcb 120 841 0 833 1 0 1 1 0 8 0 syncache 264 8 0 8 3 3 0 1 0 8 0 tcpcb 544 160 0 156 1 0 1 1 0 8 0 ipq 40 2 0 2 1 0 1 1 0 8 1 ipqe 40 4 0 4 1 0 1 1 0 8 1 inpcb 296 462 0 455 3 1 2 2 0 8 1 nd6 48 19 0 13 1 0 1 1 0 8 0 pkpcb 40 2 0 2 1 0 1 1 0 8 1 pfstscr 40 3 0 0 1 0 1 1 0 8 0 pfrktable 1344 42 0 42 2 1 1 1 0 8 1 pftag 88 6 0 6 1 0 1 1 0 8 1 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 12 0 10 2 1 1 1 0 8 0 art_heap8 4096 1 0 0 1 0 1 1 0 8 0 art_heap4 256 235 0 44 12 0 12 12 0 8 0 art_table 32 236 0 44 2 0 2 2 0 8 0 art_node 16 65 0 25 1 0 1 1 0 8 0 sysvmsgpl 40 20 0 13 1 0 1 1 0 8 0 semupl 112 3 0 3 1 1 0 1 0 8 0 semapl 112 52 0 42 1 0 1 1 0 8 0 shmpl 112 30 0 2 1 0 1 1 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino2pl 256 1945 0 547 88 0 88 88 0 8 0 ffsino 240 1945 0 547 83 0 83 83 0 8 0 nchpl 144 2696 0 1113 60 0 60 60 0 8 0 uvmvnodes 72 2190 0 0 40 0 40 40 0 8 0 vnodes 208 2190 0 0 116 0 116 116 0 8 0 namei 1024 7522 0 7522 1 0 1 1 0 8 1 vcpupl 1984 5 0 0 1 0 1 1 0 8 0 vmpool 528 8 0 3 1 0 1 1 0 8 0 pfiaddrpl 120 12 0 12 2 1 1 1 0 8 1 scsiplug 64 1 0 1 1 1 0 1 0 8 0 scxspl 192 7779 0 7779 1 0 1 1 0 8 1 plimitpl 152 42 0 35 1 0 1 1 0 8 0 sigapl 424 583 0 554 4 0 4 4 0 8 0 futexpl 56 8168 0 8168 1 0 1 1 0 8 1 knotepl 112 119 0 100 1 0 1 1 0 8 0 kqueuepl 144 102 0 100 1 0 1 1 0 8 0 pipelkpl 16 116 0 106 1 0 1 1 0 8 0 pipepl 120 232 0 213 1 0 1 1 0 8 0 fdescpl 432 567 0 554 2 0 2 2 0 8 0 filepl 120 4014 0 3919 4 0 4 4 0 8 0 lockfpl 104 97 0 96 1 0 1 1 0 8 0 lockfspl 48 41 0 40 1 0 1 1 0 8 0 sessionpl 112 19 0 9 1 0 1 1 0 8 0 pgrppl 48 25 0 15 1 0 1 1 0 8 0 ucredpl 96 512 0 505 1 0 1 1 0 8 0 zombiepl 144 554 0 554 1 0 1 1 0 8 1 processpl 920 583 0 554 4 0 4 4 0 8 0 procpl 624 1016 0 981 4 0 4 4 0 8 1 sosppl 128 11 0 11 2 1 1 1 0 8 1 sockpl 400 1357 0 1340 4 0 4 4 0 8 2 mcl64k 65536 27 0 27 1 0 1 1 0 8 1 mcl12k 12288 13 0 13 1 0 1 1 0 8 1 mcl9k 9216 4 0 4 2 1 1 1 0 8 1 mcl8k 8192 14 0 14 2 1 1 1 0 8 1 mcl4k 4096 36 0 36 2 1 1 1 0 8 1 mcl2k2 2112 3 0 3 1 1 0 1 0 8 0 mcl2k 2048 74139 0 74093 19 12 7 16 0 8 0 mtagpl 96 39 0 19 2 1 1 1 0 8 0 mbufpl 256 120527 0 120352 33 9 24 29 0 8 8 bufpl 280 3944 0 128 273 0 273 273 0 8 0 anonpl 16 71582 0 55241 90 10 80 80 0 107 12 amapchunkpl 152 2515 0 2388 11 4 7 10 0 158 0 amappl16 192 3017 0 2085 67 12 55 59 0 8 8 amappl15 184 3 0 1 1 0 1 1 0 8 0 amappl14 176 30 0 26 1 0 1 1 0 8 0 amappl13 168 203 0 199 1 0 1 1 0 8 0 amappl12 160 14 0 11 1 0 1 1 0 8 0 amappl11 152 44 0 35 1 0 1 1 0 8 0 amappl10 144 159 0 151 1 0 1 1 0 8 0 amappl9 136 400 0 398 1 0 1 1 0 8 0 amappl8 128 408 0 362 2 0 2 2 0 8 0 amappl7 120 247 0 236 1 0 1 1 0 8 0 amappl6 112 27 0 19 1 0 1 1 0 8 0 amappl5 104 544 0 533 1 0 1 1 0 8 0 amappl4 96 607 0 576 1 0 1 1 0 8 0 amappl3 88 119 0 113 1 0 1 1 0 8 0 amappl2 80 3637 0 3581 2 0 2 2 0 8 0 amappl1 72 19575 0 19175 24 14 10 17 0 8 1 amappl 80 1264 0 1223 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 31 0 1 1 0 1 1 0 8 0 uaddrrnd 24 575 0 557 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 575 0 557 1 0 1 1 0 8 0 vmmpekpl 168 7518 0 7488 2 0 2 2 0 8 0 vmmpepl 168 74198 0 72234 153 21 132 132 0 357 38 vmsppl 272 574 0 557 2 0 2 2 0 8 0 pdppl 4096 1156 0 1119 7 1 6 6 0 8 1 pvpl 32 211398 0 192655 192 8 184 188 0 265 25 pmappl 200 574 0 557 2 0 2 2 0 8 1 extentpl 40 53 0 36 1 0 1 1 0 8 0 phpool 112 267 0 27 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(ffffffff823c7279) at panic+0x15c sys/kern/subr_prf.c:207 m_copym(fffffd805e431800,244,144,2) at m_copym+0x553 sys/kern/uipc_mbuf.c:695 tcp_output(ffff800000ac2540) at tcp_output+0x154d sys/netinet/tcp_output.c:673 tcp_usrreq(fffffd805da6f4b8,9,fffffd805e431700,0,0,ffff80001d717010) at tcp_usrreq+0xa54 sosend(fffffd805da6f4b8,0,ffff80001d71e398,0,0,80) at sosend+0x669 sys/kern/uipc_socket.c:555 dofilewritev(ffff80001d717010,4,ffff80001d71e398,0,ffff80001d71e480) at dofilewritev+0x1ab sys/kern/sys_generic.c:365 sys_write(ffff80001d717010,ffff80001d71e430,ffff80001d71e480) at sys_write+0x83 sys/kern/sys_generic.c:285 syscall(ffff80001d71e500) at syscall+0x507 sys/arch/amd64/amd64/trap.c:570 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7f7ffffd1830, 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(ffffffff823c7279) at panic+0x15c sys/kern/subr_prf.c:207 m_copym(fffffd805e431800,244,144,2) at m_copym+0x553 sys/kern/uipc_mbuf.c:695 tcp_output(ffff800000ac2540) at tcp_output+0x154d sys/netinet/tcp_output.c:673 tcp_usrreq(fffffd805da6f4b8,9,fffffd805e431700,0,0,ffff80001d717010) at tcp_usrreq+0xa54 sosend(fffffd805da6f4b8,0,ffff80001d71e398,0,0,80) at sosend+0x669 sys/kern/uipc_socket.c:555 dofilewritev(ffff80001d717010,4,ffff80001d71e398,0,ffff80001d71e480) at dofilewritev+0x1ab sys/kern/sys_generic.c:365 sys_write(ffff80001d717010,ffff80001d71e430,ffff80001d71e480) at sys_write+0x83 sys/kern/sys_generic.c:285 syscall(ffff80001d71e500) at syscall+0x507 sys/arch/amd64/amd64/trap.c:570 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7f7ffffd1830, count: -10