login: panic: m_copym0: short mbuf chain Stopped at db_enter+0x18: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND *176442 6966 0 0x12 0 0 sshd db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:398 panic(ffffffff823d660f) at panic+0x15c sys/kern/subr_prf.c:207 m_copym(fffffd805c804500,244,184,2) at m_copym+0x553 sys/kern/uipc_mbuf.c:695 tcp_output(ffff800000ac3540) at tcp_output+0x154d sys/netinet/tcp_output.c:673 tcp_usrreq(fffffd805da777d8,9,fffffd805c804400,0,0,ffff80001d71c010) at tcp_usrreq+0xa54 sosend(fffffd805da777d8,0,ffff80001d6cd5a8,0,0,80) at sosend+0x669 sys/kern/uipc_socket.c:555 dofilewritev(ffff80001d71c010,4,ffff80001d6cd5a8,0,ffff80001d6cd690) at dofilewritev+0x1ab sys/kern/sys_generic.c:365 sys_write(ffff80001d71c010,ffff80001d6cd640,ffff80001d6cd690) at sys_write+0x83 sys/kern/sys_generic.c:285 syscall(ffff80001d6cd710) at syscall+0x507 sys/arch/amd64/amd64/trap.c:570 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7f7ffffbd410, 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(ffffffff823d660f) at panic+0x15c sys/kern/subr_prf.c:207 m_copym(fffffd805c804500,244,184,2) at m_copym+0x553 sys/kern/uipc_mbuf.c:695 tcp_output(ffff800000ac3540) at tcp_output+0x154d sys/netinet/tcp_output.c:673 tcp_usrreq(fffffd805da777d8,9,fffffd805c804400,0,0,ffff80001d71c010) at tcp_usrreq+0xa54 sosend(fffffd805da777d8,0,ffff80001d6cd5a8,0,0,80) at sosend+0x669 sys/kern/uipc_socket.c:555 dofilewritev(ffff80001d71c010,4,ffff80001d6cd5a8,0,ffff80001d6cd690) at dofilewritev+0x1ab sys/kern/sys_generic.c:365 sys_write(ffff80001d71c010,ffff80001d6cd640,ffff80001d6cd690) at sys_write+0x83 sys/kern/sys_generic.c:285 syscall(ffff80001d6cd710) at syscall+0x507 sys/arch/amd64/amd64/trap.c:570 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7f7ffffbd410, count: -10 ddb> show registers rdi 0 rsi 0x1 rbp 0xffff80001d6cd070 rbx 0xffff80001d6cd120 rdx 0x2 rcx 0 rax 0x1 r8 0xffffffff81443f7f kprintf+0x15f r9 0x1 r10 0x2 r11 0xfd32ff67264c3511 r12 0x3000000008 r13 0xffff80001d6cd080 r14 0x100 r15 0x1 rip 0xffffffff8197d558 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff80001d6cd060 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb> show proc PROC (sshd) pid=176442 stat=onproc flags process=12 proc=0 pri=24, usrpri=50, nice=20 forw=0xffffffffffffffff, list=0xffff80001d71c280,0xffff80001d71c770 process=0xffff80001d706af8 user=0xffff80001d6c8000, vmspace=0xfffffd806bc0a330 estcpu=0, cpticks=0, pctcpu=0.1 user=0, sys=0, intr=0 ddb> ps PID TID PPID UID S FLAGS WAIT COMMAND 82375 34881 82856 0 3 0x82 piperd syz-executor.0 53366 136440 82856 0 2 0x2 syz-executor.1 82856 188963 95342 0 3 0x82 thrsleep syz-fuzzer 82856 449937 95342 0 3 0x4000082 nanosleep syz-fuzzer 82856 520445 95342 0 2 0x4000002 syz-fuzzer 82856 343717 95342 0 3 0x4000082 thrsleep syz-fuzzer 82856 45643 95342 0 3 0x4000082 thrsleep syz-fuzzer 82856 225634 95342 0 3 0x4000082 thrsleep syz-fuzzer 82856 342241 95342 0 3 0x4000082 thrsleep syz-fuzzer 82856 366255 95342 0 3 0x4000082 thrsleep syz-fuzzer 82856 223763 95342 0 3 0x4000082 thrsleep syz-fuzzer 95342 424433 6966 0 3 0x10008a pause ksh * 6966 176442 16932 0 7 0x12 sshd 79080 403307 1 0 3 0x100083 ttyin getty 16932 368987 1 0 3 0x80 select sshd 49199 168015 13318 73 3 0x100090 kqread syslogd 13318 192642 1 0 3 0x100082 netio syslogd 41473 445443 1 77 3 0x100090 poll dhclient 74669 108025 1 0 3 0x80 poll dhclient 64340 277710 0 0 3 0x14200 bored smr 89353 385039 0 0 2 0x14200 zerothread 40487 87409 0 0 3 0x14200 aiodoned aiodoned 85917 458575 0 0 3 0x14200 syncer update 43148 462768 0 0 3 0x14200 cleaner cleaner 97319 145553 0 0 3 0x14200 reaper reaper 97763 133432 0 0 3 0x14200 pgdaemon pagedaemon 64421 229110 0 0 3 0x14200 bored crynlk 44029 296490 0 0 3 0x14200 bored crypto 70260 103246 0 0 3 0x40014200 acpi0 acpi0 97549 367004 0 0 3 0x14200 bored softnet 20237 138286 0 0 3 0x14200 bored systqmp 50200 76212 0 0 3 0x14200 bored systq 99488 292913 0 0 3 0x40014200 bored softclock 10937 120319 0 0 3 0x40014200 idle0 1 330570 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 9453 6326K 6326K 78643K 10554 0 pcb 13 8K 8K 78643K 17 0 rtable 105 3K 3K 78643K 195 0 ifaddr 44 10K 10K 78643K 48 0 counters 21 16K 16K 78643K 21 0 ioctlops 0 0K 4K 78643K 21 0 iov 0 0K 2K 78643K 4 0 mount 1 1K 1K 78643K 1 0 vnodes 1216 76K 77K 78643K 1222 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 4 0K 0K 78643K 4 0 dirhash 12 2K 2K 78643K 12 0 ACPI 1809 195K 288K 78643K 12938 0 file desc 4 9K 25K 78643K 46 0 proc 48 38K 63K 78643K 361 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 3 0 in_multi 33 2K 2K 78643K 41 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 121 23K 23K 78643K 981 0 UVM aobj 3 2K 2K 78643K 3 0 memdesc 1 4K 4K 78643K 1 0 crypto data 1 1K 1K 78643K 1 0 NDP 6 0K 0K 78643K 12 0 temp 66 3847K 3911K 78643K 1801 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 47 0 3 2 0 2 2 0 8 0 unpcb 120 31 0 23 1 0 1 1 0 8 0 syncache 264 4 0 4 1 1 0 1 0 8 0 tcpqe 32 102 0 102 1 0 1 1 0 8 1 tcpcb 544 10 0 6 1 0 1 1 0 8 0 inpcb 296 48 0 41 1 0 1 1 0 8 0 nd6 48 8 0 2 1 0 1 1 0 8 0 pfrule 1360 4 0 2 1 0 1 1 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 46 0 6 1 0 1 1 0 8 0 semapl 112 2 0 0 1 0 1 1 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino2pl 256 1436 0 38 88 0 88 88 0 8 0 ffsino 240 1436 0 38 83 0 83 83 0 8 0 nchpl 144 1672 0 70 60 0 60 60 0 8 0 uvmvnodes 72 1479 0 0 27 0 27 27 0 8 0 vnodes 208 1479 0 0 78 0 78 78 0 8 0 namei 1024 4132 0 4132 1 0 1 1 0 8 1 scxspl 192 4616 0 4616 1 0 1 1 0 8 1 plimitpl 152 16 0 9 1 0 1 1 0 8 0 sigapl 424 232 0 205 4 0 4 4 0 8 0 futexpl 56 241 0 241 1 0 1 1 0 8 1 knotepl 112 61 0 42 1 0 1 1 0 8 0 kqueuepl 144 4 0 2 1 0 1 1 0 8 0 pipepl 272 76 0 66 1 0 1 1 0 8 0 fdescpl 432 218 0 205 2 0 2 2 0 8 0 filepl 120 1084 0 989 4 0 4 4 0 8 1 lockfpl 104 10 0 9 1 0 1 1 0 8 0 lockfspl 48 5 0 4 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 55 0 48 1 0 1 1 0 8 0 zombiepl 144 205 0 205 1 0 1 1 0 8 1 processpl 928 232 0 205 4 0 4 4 0 8 0 procpl 624 259 0 224 4 0 4 4 0 8 1 sockpl 400 98 0 81 3 0 3 3 0 8 1 mcl64k 65536 4 0 4 1 0 1 1 0 8 1 mcl4k 4096 10 0 10 2 1 1 1 0 8 1 mcl2k 2048 92311 0 92264 15 2 13 13 0 8 7 mtagpl 96 2 0 2 1 1 0 1 0 8 0 mbufpl 256 145453 0 145362 13 1 12 12 0 8 1 bufpl 280 3294 0 126 227 0 227 227 0 8 0 anonpl 16 42644 0 27827 77 1 76 76 0 107 16 amapchunkpl 152 1121 0 994 8 0 8 8 0 158 2 amappl16 192 1190 0 386 51 0 51 51 0 8 10 amappl15 184 1 0 0 1 0 1 1 0 8 0 amappl14 176 27 0 22 1 0 1 1 0 8 0 amappl13 168 39 0 34 1 0 1 1 0 8 0 amappl12 160 20 0 17 2 1 1 1 0 8 0 amappl11 152 46 0 37 1 0 1 1 0 8 0 amappl10 144 18 0 11 1 0 1 1 0 8 0 amappl9 136 372 0 370 1 0 1 1 0 8 0 amappl8 128 319 0 278 2 0 2 2 0 8 0 amappl7 120 107 0 95 1 0 1 1 0 8 0 amappl6 112 23 0 20 1 0 1 1 0 8 0 amappl5 104 170 0 160 1 0 1 1 0 8 0 amappl4 96 415 0 389 1 0 1 1 0 8 0 amappl3 88 99 0 94 1 0 1 1 0 8 0 amappl2 80 920 0 865 2 0 2 2 0 8 0 amappl1 72 13957 0 13555 22 5 17 17 0 8 8 amappl 80 509 0 471 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 2 0 0 1 0 1 1 0 8 0 uaddrrnd 24 218 0 205 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 218 0 205 1 0 1 1 0 8 0 vmmpekpl 168 5709 0 5684 2 0 2 2 0 8 0 vmmpepl 168 34419 0 32626 115 4 111 111 0 357 29 vmsppl 272 217 0 205 2 0 2 2 0 8 1 pdppl 4096 442 0 410 6 0 6 6 0 8 1 pvpl 32 131460 0 113774 181 0 181 181 0 265 36 pmappl 200 217 0 205 1 0 1 1 0 8 0 extentpl 40 53 0 36 1 0 1 1 0 8 0 phpool 112 239 0 6 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(ffffffff823d660f) at panic+0x15c sys/kern/subr_prf.c:207 m_copym(fffffd805c804500,244,184,2) at m_copym+0x553 sys/kern/uipc_mbuf.c:695 tcp_output(ffff800000ac3540) at tcp_output+0x154d sys/netinet/tcp_output.c:673 tcp_usrreq(fffffd805da777d8,9,fffffd805c804400,0,0,ffff80001d71c010) at tcp_usrreq+0xa54 sosend(fffffd805da777d8,0,ffff80001d6cd5a8,0,0,80) at sosend+0x669 sys/kern/uipc_socket.c:555 dofilewritev(ffff80001d71c010,4,ffff80001d6cd5a8,0,ffff80001d6cd690) at dofilewritev+0x1ab sys/kern/sys_generic.c:365 sys_write(ffff80001d71c010,ffff80001d6cd640,ffff80001d6cd690) at sys_write+0x83 sys/kern/sys_generic.c:285 syscall(ffff80001d6cd710) at syscall+0x507 sys/arch/amd64/amd64/trap.c:570 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7f7ffffbd410, 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(ffffffff823d660f) at panic+0x15c sys/kern/subr_prf.c:207 m_copym(fffffd805c804500,244,184,2) at m_copym+0x553 sys/kern/uipc_mbuf.c:695 tcp_output(ffff800000ac3540) at tcp_output+0x154d sys/netinet/tcp_output.c:673 tcp_usrreq(fffffd805da777d8,9,fffffd805c804400,0,0,ffff80001d71c010) at tcp_usrreq+0xa54 sosend(fffffd805da777d8,0,ffff80001d6cd5a8,0,0,80) at sosend+0x669 sys/kern/uipc_socket.c:555 dofilewritev(ffff80001d71c010,4,ffff80001d6cd5a8,0,ffff80001d6cd690) at dofilewritev+0x1ab sys/kern/sys_generic.c:365 sys_write(ffff80001d71c010,ffff80001d6cd640,ffff80001d6cd690) at sys_write+0x83 sys/kern/sys_generic.c:285 syscall(ffff80001d6cd710) at syscall+0x507 sys/arch/amd64/amd64/trap.c:570 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7f7ffffbd410, count: -10