panic: m_copym0: short mbuf chain Stopped at db_enter+0x18: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND * 80929 75263 0 0x12 0 0 sshd db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:398 panic(ffffffff823cb859) at panic+0x15c sys/kern/subr_prf.c:207 m_copym(fffffd805e476200,3e4,34c,2) at m_copym+0x553 sys/kern/uipc_mbuf.c:695 tcp_output(ffff800000ac3100) at tcp_output+0x154d sys/netinet/tcp_output.c:673 tcp_usrreq(fffffd805da83328,9,fffffd805e476100,0,0,ffff80001d71c280) at tcp_usrreq+0xa54 sosend(fffffd805da83328,0,ffff80001d6cd418,0,0,80) at sosend+0x669 sys/kern/uipc_socket.c:555 dofilewritev(ffff80001d71c280,4,ffff80001d6cd418,0,ffff80001d6cd500) at dofilewritev+0x1ab sys/kern/sys_generic.c:365 sys_write(ffff80001d71c280,ffff80001d6cd4b0,ffff80001d6cd500) at sys_write+0x83 sys/kern/sys_generic.c:285 syscall(ffff80001d6cd580) at syscall+0x507 sys/arch/amd64/amd64/trap.c:570 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7f7fffff1c90, 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(ffffffff823cb859) at panic+0x15c sys/kern/subr_prf.c:207 m_copym(fffffd805e476200,3e4,34c,2) at m_copym+0x553 sys/kern/uipc_mbuf.c:695 tcp_output(ffff800000ac3100) at tcp_output+0x154d sys/netinet/tcp_output.c:673 tcp_usrreq(fffffd805da83328,9,fffffd805e476100,0,0,ffff80001d71c280) at tcp_usrreq+0xa54 sosend(fffffd805da83328,0,ffff80001d6cd418,0,0,80) at sosend+0x669 sys/kern/uipc_socket.c:555 dofilewritev(ffff80001d71c280,4,ffff80001d6cd418,0,ffff80001d6cd500) at dofilewritev+0x1ab sys/kern/sys_generic.c:365 sys_write(ffff80001d71c280,ffff80001d6cd4b0,ffff80001d6cd500) at sys_write+0x83 sys/kern/sys_generic.c:285 syscall(ffff80001d6cd580) at syscall+0x507 sys/arch/amd64/amd64/trap.c:570 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7f7fffff1c90, count: -10 ddb> show registers rdi 0 rsi 0x1 rbp 0xffff80001d6ccee0 rbx 0xffff80001d6ccf90 rdx 0x2 rcx 0 rax 0x1 r8 0xffffffff8140a10f kprintf+0x15f r9 0x1 r10 0x2 r11 0xde1794ddc0ae2d3e r12 0x3000000008 r13 0xffff80001d6ccef0 r14 0x100 r15 0x1 rip 0xffffffff814764a8 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff80001d6cced0 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb> show proc PROC (sshd) pid=80929 stat=onproc flags process=12 proc=0 pri=24, usrpri=50, nice=20 forw=0xffffffffffffffff, list=0xffff80001d71d390,0xffff80001d71c770 process=0xffff80001d7003b8 user=0xffff80001d6c8000, vmspace=0xfffffd806bc0aaa0 estcpu=0, cpticks=0, pctcpu=0.0 user=0, sys=0, intr=0 ddb> ps PID TID PPID UID S FLAGS WAIT COMMAND 35437 510536 97247 0 2 0 syz-executor.1 35437 236484 97247 0 3 0x4000080 rest syz-executor.1 28863 158139 0 0 3 0x14200 bored sosplice 40958 12325 0 0 3 0x14200 acct acct 29128 432270 26136 0 2 0x2 syz-executor.0 97247 194507 26136 0 3 0x82 nanosleep syz-executor.1 26136 168478 93612 0 3 0x82 thrsleep syz-fuzzer 26136 100981 93612 0 2 0x4000002 syz-fuzzer 26136 347507 93612 0 3 0x4000082 thrsleep syz-fuzzer 26136 131479 93612 0 3 0x4000082 thrsleep syz-fuzzer 26136 205537 93612 0 3 0x4000082 thrsleep syz-fuzzer 26136 183598 93612 0 2 0x4000002 syz-fuzzer 26136 267663 93612 0 3 0x4000082 thrsleep syz-fuzzer 26136 357778 93612 0 3 0x4000082 thrsleep syz-fuzzer 93612 382814 75263 0 3 0x10008a pause ksh *75263 80929 68065 0 7 0x12 sshd 35953 242840 1 0 3 0x100083 ttyin getty 68065 357986 1 0 3 0x80 select sshd 36637 344975 77744 73 3 0x100090 kqread syslogd 77744 398407 1 0 3 0x100082 netio syslogd 15420 60964 1 77 3 0x100090 poll dhclient 54533 321545 1 0 3 0x80 poll dhclient 67879 30208 0 0 3 0x14200 bored smr 64950 181482 0 0 2 0x14200 zerothread 70178 247271 0 0 3 0x14200 aiodoned aiodoned 71633 380705 0 0 3 0x14200 syncer update 10369 225612 0 0 3 0x14200 cleaner cleaner 38471 238615 0 0 3 0x14200 reaper reaper 11609 1338 0 0 3 0x14200 pgdaemon pagedaemon 38745 383157 0 0 3 0x14200 bored crynlk 70254 124777 0 0 3 0x14200 bored crypto 24263 122007 0 0 3 0x40014200 acpi0 acpi0 37851 11899 0 0 3 0x14200 bored softnet 70229 361689 0 0 3 0x14200 bored systqmp 80282 439001 0 0 3 0x14200 bored systq 32233 18472 0 0 3 0x40014200 bored softclock 83078 218049 0 0 3 0x40014200 idle0 1 240759 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 9476 6333K 6587K 78643K 10868 0 pcb 13 8K 8K 78643K 45 0 rtable 138 9K 10K 78643K 345 0 ifaddr 63 14K 14K 78643K 109 0 sysctl 2 0K 0K 78643K 2 0 counters 21 16K 16K 78643K 26 0 ioctlops 0 0K 4K 78643K 77 0 iov 0 0K 16K 78643K 24 0 mount 1 1K 1K 78643K 1 0 vnodes 1223 77K 77K 78643K 1331 0 UFS quota 1 32K 32K 78643K 1 0 UFS mount 5 36K 36K 78643K 5 0 shm 2 1K 5K 78643K 5 0 VM map 2 0K 0K 78643K 2 0 sem 12 0K 1K 78643K 50 0 dirhash 12 2K 2K 78643K 12 0 ACPI 1809 195K 288K 78643K 12938 0 file desc 5 13K 25K 78643K 286 0 sigio 0 0K 0K 78643K 6 0 proc 48 38K 54K 78643K 369 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 14 0 in_multi 51 3K 3K 78643K 95 0 ether_multi 1 0K 0K 78643K 7 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 223 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 129 23K 25K 78643K 1528 0 UVM aobj 15 4K 4K 78643K 15 0 memdesc 1 4K 4K 78643K 1 0 crypto data 1 1K 1K 78643K 1 0 ip6_options 0 0K 0K 78643K 20 0 NDP 9 0K 0K 78643K 24 0 temp 85 3852K 3916K 78643K 7436 0 kqueue 3 4K 10K 78643K 14 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 33 0 31 1 0 1 1 0 8 0 rtentry 112 53 0 7 2 0 2 2 0 8 0 unpcb 120 167 0 159 1 0 1 1 0 8 0 syncache 264 6 0 6 2 2 0 1 0 8 0 tcpqe 32 301 0 301 1 1 0 1 0 8 0 tcpcb 544 72 0 67 1 0 1 1 0 8 0 ipq 40 2 0 2 1 1 0 1 0 8 0 ipqe 40 4 0 4 1 1 0 1 0 8 0 inpcb 296 212 0 202 3 1 2 2 0 8 1 ip6q 72 1 0 1 1 1 0 1 0 8 0 ip6af 40 3 0 3 1 1 0 1 0 8 0 nd6 48 13 0 6 1 0 1 1 0 8 0 pkpcb 40 6 0 6 2 2 0 1 0 8 0 pfstscr 40 2 0 2 1 0 1 1 0 8 1 pfrktable 1344 39 0 27 2 1 1 2 0 8 0 pftag 88 3 0 2 2 1 1 1 0 8 0 pfstkey 112 4 0 4 1 0 1 1 0 8 1 pfstate 328 2 0 2 1 0 1 1 0 8 1 pfrule 1360 24 0 6 2 0 2 2 0 8 0 art_heap8 4096 1 0 0 1 0 1 1 0 8 0 art_heap4 256 188 0 0 12 0 12 12 0 8 0 art_table 32 189 0 0 2 0 2 2 0 8 0 art_node 16 52 0 11 1 0 1 1 0 8 0 sysvmsgpl 40 12 0 5 1 0 1 1 0 8 0 semupl 112 2 0 2 1 1 0 1 0 8 0 semapl 112 44 0 34 1 0 1 1 0 8 0 shmpl 112 12 0 0 1 0 1 1 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino2pl 256 1751 0 352 88 0 88 88 0 8 0 ffsino 240 1751 0 352 83 0 83 83 0 8 0 nchpl 144 2520 0 912 60 0 60 60 0 8 0 uvmvnodes 72 1871 0 0 35 0 35 35 0 8 0 vnodes 208 1871 0 0 99 0 99 99 0 8 0 namei 1024 6369 0 6369 4 3 1 1 0 8 1 vcpupl 1984 1 0 0 1 0 1 1 0 8 0 vmpool 528 4 0 3 1 0 1 1 0 8 0 pfiaddrpl 120 18 0 6 1 0 1 1 0 8 0 scxspl 192 6741 0 6741 1 0 1 1 0 8 1 plimitpl 152 33 0 26 1 0 1 1 0 8 0 sigapl 424 474 0 444 4 0 4 4 0 8 0 futexpl 56 4920 0 4920 3 2 1 1 0 8 1 knotepl 112 80 0 61 1 0 1 1 0 8 0 kqueuepl 144 44 0 42 1 0 1 1 0 8 0 pipepl 272 96 0 86 1 0 1 1 0 8 0 fdescpl 432 458 0 444 2 0 2 2 0 8 0 filepl 120 2681 0 2582 4 0 4 4 0 8 1 lockfpl 104 85 0 83 1 0 1 1 0 8 0 lockfspl 48 29 0 27 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 96 265 0 258 1 0 1 1 0 8 0 zombiepl 144 444 0 444 2 1 1 1 0 8 1 processpl 928 474 0 444 4 0 4 4 0 8 0 procpl 624 789 0 751 4 0 4 4 0 8 0 sosppl 128 6 0 6 2 1 1 1 0 8 1 sockpl 400 418 0 398 5 2 3 3 0 8 1 mcl64k 65536 2 0 2 1 1 0 1 0 8 0 mcl16k 16384 1 0 1 1 1 0 1 0 8 0 mcl12k 12288 7 0 7 3 2 1 1 0 8 1 mcl9k 9216 3 0 3 2 2 0 1 0 8 0 mcl8k 8192 6 0 6 3 3 0 1 0 8 0 mcl4k 4096 36 0 36 4 3 1 1 0 8 1 mcl2k 2048 94039 0 93981 22 14 8 18 0 8 0 mtagpl 96 28 0 6 2 1 1 1 0 8 0 mbufpl 256 150888 0 150699 17 2 15 15 0 8 1 bufpl 280 3746 0 127 259 0 259 259 0 8 0 anonpl 16 61696 0 46247 76 1 75 75 0 107 0 amapchunkpl 152 2348 0 2208 13 6 7 13 0 158 0 amappl16 192 2220 0 1207 53 0 53 53 0 8 2 amappl15 184 9 0 7 1 0 1 1 0 8 0 amappl14 176 25 0 20 1 0 1 1 0 8 0 amappl13 168 35 0 31 1 0 1 1 0 8 0 amappl12 160 16 0 11 1 0 1 1 0 8 0 amappl11 152 44 0 35 1 0 1 1 0 8 0 amappl10 144 140 0 135 1 0 1 1 0 8 0 amappl9 136 493 0 491 1 0 1 1 0 8 0 amappl8 128 455 0 414 2 0 2 2 0 8 0 amappl7 120 234 0 222 1 0 1 1 0 8 0 amappl6 112 23 0 19 1 0 1 1 0 8 0 amappl5 104 400 0 389 1 0 1 1 0 8 0 amappl4 96 422 0 396 1 0 1 1 0 8 0 amappl3 88 118 0 112 1 0 1 1 0 8 0 amappl2 80 2837 0 2769 2 0 2 2 0 8 0 amappl1 72 18968 0 18553 23 14 9 17 0 8 0 amappl 80 1047 0 1003 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 14 0 0 1 0 1 1 0 8 0 uaddrrnd 24 462 0 447 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 462 0 447 1 0 1 1 0 8 0 vmmpekpl 168 6716 0 6690 3 1 2 2 0 8 0 vmmpepl 168 62265 0 60152 156 43 113 149 0 357 20 vmsppl 272 461 0 447 3 1 2 2 0 8 1 pdppl 4096 930 0 895 6 1 5 6 0 8 0 pvpl 32 184797 0 166333 183 8 175 179 0 265 0 pmappl 200 461 0 447 1 0 1 1 0 8 0 extentpl 40 53 0 36 1 0 1 1 0 8 0 phpool 112 263 0 33 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(ffffffff823cb859) at panic+0x15c sys/kern/subr_prf.c:207 m_copym(fffffd805e476200,3e4,34c,2) at m_copym+0x553 sys/kern/uipc_mbuf.c:695 tcp_output(ffff800000ac3100) at tcp_output+0x154d sys/netinet/tcp_output.c:673 tcp_usrreq(fffffd805da83328,9,fffffd805e476100,0,0,ffff80001d71c280) at tcp_usrreq+0xa54 sosend(fffffd805da83328,0,ffff80001d6cd418,0,0,80) at sosend+0x669 sys/kern/uipc_socket.c:555 dofilewritev(ffff80001d71c280,4,ffff80001d6cd418,0,ffff80001d6cd500) at dofilewritev+0x1ab sys/kern/sys_generic.c:365 sys_write(ffff80001d71c280,ffff80001d6cd4b0,ffff80001d6cd500) at sys_write+0x83 sys/kern/sys_generic.c:285 syscall(ffff80001d6cd580) at syscall+0x507 sys/arch/amd64/amd64/trap.c:570 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7f7fffff1c90, 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(ffffffff823cb859) at panic+0x15c sys/kern/subr_prf.c:207 m_copym(fffffd805e476200,3e4,34c,2) at m_copym+0x553 sys/kern/uipc_mbuf.c:695 tcp_output(ffff800000ac3100) at tcp_output+0x154d sys/netinet/tcp_output.c:673 tcp_usrreq(fffffd805da83328,9,fffffd805e476100,0,0,ffff80001d71c280) at tcp_usrreq+0xa54 sosend(fffffd805da83328,0,ffff80001d6cd418,0,0,80) at sosend+0x669 sys/kern/uipc_socket.c:555 dofilewritev(ffff80001d71c280,4,ffff80001d6cd418,0,ffff80001d6cd500) at dofilewritev+0x1ab sys/kern/sys_generic.c:365 sys_write(ffff80001d71c280,ffff80001d6cd4b0,ffff80001d6cd500) at sys_write+0x83 sys/kern/sys_generic.c:285 syscall(ffff80001d6cd580) at syscall+0x507 sys/arch/amd64/amd64/trap.c:570 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7f7fffff1c90, count: -10