panic: m_copym0: short mbuf chain Stopped at db_enter+0x18: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND *381024 34981 0 0x12 0 0 sshd db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:398 panic(ffffffff823ad659) at panic+0x15c sys/kern/subr_prf.c:207 m_copym(fffffd8053988f00,3ac,b4,2) at m_copym+0x553 sys/kern/uipc_mbuf.c:695 tcp_output(ffff800000ac0760) at tcp_output+0x154d sys/netinet/tcp_output.c:673 tcp_usrreq(fffffd805da71198,9,fffffd8053988e00,0,0,ffff80001d717c40) at tcp_usrreq+0xa54 sosend(fffffd805da71198,0,ffff80001d71edc8,0,0,80) at sosend+0x669 sys/kern/uipc_socket.c:549 dofilewritev(ffff80001d717c40,4,ffff80001d71edc8,0,ffff80001d71eeb0) at dofilewritev+0x1ab sys/kern/sys_generic.c:365 sys_write(ffff80001d717c40,ffff80001d71ee60,ffff80001d71eeb0) at sys_write+0x83 sys/kern/sys_generic.c:285 syscall(ffff80001d71ef30) at syscall+0x507 sys/arch/amd64/amd64/trap.c:570 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7f7ffffc7450, 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(ffffffff823ad659) at panic+0x15c sys/kern/subr_prf.c:207 m_copym(fffffd8053988f00,3ac,b4,2) at m_copym+0x553 sys/kern/uipc_mbuf.c:695 tcp_output(ffff800000ac0760) at tcp_output+0x154d sys/netinet/tcp_output.c:673 tcp_usrreq(fffffd805da71198,9,fffffd8053988e00,0,0,ffff80001d717c40) at tcp_usrreq+0xa54 sosend(fffffd805da71198,0,ffff80001d71edc8,0,0,80) at sosend+0x669 sys/kern/uipc_socket.c:549 dofilewritev(ffff80001d717c40,4,ffff80001d71edc8,0,ffff80001d71eeb0) at dofilewritev+0x1ab sys/kern/sys_generic.c:365 sys_write(ffff80001d717c40,ffff80001d71ee60,ffff80001d71eeb0) at sys_write+0x83 sys/kern/sys_generic.c:285 syscall(ffff80001d71ef30) at syscall+0x507 sys/arch/amd64/amd64/trap.c:570 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7f7ffffc7450, count: -10 ddb> show registers rdi 0 rsi 0x1 rbp 0xffff80001d71e890 rbx 0xffff80001d71e940 rdx 0x2 rcx 0 rax 0x1 r8 0xffffffff81ad64bf kprintf+0x15f r9 0x1 r10 0x2 r11 0x845f88c4c3a7ba00 r12 0x3000000008 r13 0xffff80001d71e8a0 r14 0x100 r15 0x1 rip 0xffffffff8181e468 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff80001d71e880 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb> show proc PROC (sshd) pid=381024 stat=onproc flags process=12 proc=0 pri=24, usrpri=50, nice=20 forw=0xffffffffffffffff, list=0xffff80001d718ae0,0xffff80001d717020 process=0xffff8000ffff8ae0 user=0xffff80001d719000, vmspace=0xfffffd806bc0abb0 estcpu=0, cpticks=0, pctcpu=0.0 user=0, sys=0, intr=0 ddb> ps PID TID PPID UID S FLAGS WAIT COMMAND 33722 262639 77216 0 2 0 syz-executor.0 33722 516829 77216 0 2 0x4000000 syz-executor.0 15752 143534 0 0 3 0x14200 acct acct 91398 327484 0 0 3 0x14200 bored sosplice 77216 277506 1863 0 3 0x82 nanosleep syz-executor.0 2147 74858 1863 0 2 0x2 syz-executor.1 1863 481865 43915 0 2 0x2 syz-fuzzer 1863 317120 43915 0 2 0x4000002 syz-fuzzer 1863 125762 43915 0 3 0x4000082 thrsleep syz-fuzzer 1863 432961 43915 0 3 0x4000082 thrsleep syz-fuzzer 1863 274652 43915 0 3 0x4000082 thrsleep syz-fuzzer 1863 46730 43915 0 3 0x4000082 thrsleep syz-fuzzer 1863 392537 43915 0 3 0x4000082 thrsleep syz-fuzzer 43915 415358 34981 0 3 0x10008a pause ksh *34981 381024 17983 0 7 0x12 sshd 14096 468004 1 0 3 0x100083 ttyin getty 17983 250604 1 0 3 0x80 select sshd 27560 407002 59090 73 3 0x100090 kqread syslogd 59090 212774 1 0 3 0x100082 netio syslogd 94084 26261 1 77 3 0x100090 poll dhclient 36412 196181 1 0 3 0x80 poll dhclient 1414 428383 0 0 3 0x14200 bored smr 80211 138288 0 0 2 0x14200 zerothread 28918 483087 0 0 3 0x14200 aiodoned aiodoned 47073 221454 0 0 3 0x14200 syncer update 72069 124657 0 0 3 0x14200 cleaner cleaner 42110 342970 0 0 3 0x14200 reaper reaper 36737 188627 0 0 3 0x14200 pgdaemon pagedaemon 12030 133896 0 0 3 0x14200 bored crynlk 12713 157685 0 0 3 0x14200 bored crypto 18858 430835 0 0 3 0x40014200 acpi0 acpi0 56916 375445 0 0 3 0x14200 bored softnet 70253 220481 0 0 3 0x14200 bored systqmp 57173 257206 0 0 3 0x14200 bored systq 93603 29463 0 0 3 0x40014200 bored softclock 39994 89044 0 0 3 0x40014200 idle0 1 269609 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 9489 6339K 6856K 78643K 10924 0 pcb 13 8K 8K 78643K 71 0 rtable 110 5K 7K 78643K 294 0 ifaddr 62 12K 13K 78643K 89 0 counters 21 16K 16K 78643K 23 0 ioctlops 0 0K 4K 78643K 53 0 iov 0 0K 12K 78643K 28 0 mount 1 1K 1K 78643K 1 0 vnodes 1217 77K 77K 78643K 1325 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 20 0 dirhash 12 2K 2K 78643K 12 0 ACPI 1809 195K 288K 78643K 12938 0 file desc 5 13K 25K 78643K 251 0 sigio 0 0K 0K 78643K 4 0 proc 49 38K 54K 78643K 389 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 23 0 in_multi 36 2K 2K 78643K 64 0 ether_multi 1 0K 0K 78643K 6 0 mrt 0 0K 0K 78643K 2 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 229 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 119 39K 47K 78643K 1437 0 UVM aobj 6 2K 2K 78643K 8 0 memdesc 1 4K 4K 78643K 1 0 crypto data 1 1K 1K 78643K 1 0 ip6_options 0 0K 0K 78643K 26 0 NDP 11 0K 0K 78643K 17 0 temp 84 3846K 3912K 78643K 10501 0 kqueue 3 4K 12K 78643K 23 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 35 0 33 1 0 1 1 0 8 0 rtentry 112 49 0 8 2 0 2 2 0 8 0 unpcb 120 214 0 206 2 0 2 2 0 8 1 syncache 264 8 0 8 2 2 0 1 0 8 0 tcpqe 32 168 0 168 1 1 0 1 0 8 0 tcpcb 544 452 0 448 2 1 1 2 0 8 0 ipq 40 1 0 1 1 0 1 1 0 8 1 ipqe 40 45 0 45 1 0 1 1 0 8 1 inpcb 280 628 0 621 3 1 2 2 0 8 1 nd6 48 7 0 3 1 0 1 1 0 8 0 pfrktable 1344 27 0 22 2 1 1 1 0 8 0 pftag 88 6 0 6 2 2 0 1 0 8 0 pfrule 1360 18 0 6 1 0 1 1 0 8 0 art_heap8 4096 1 0 0 1 0 1 1 0 8 0 art_heap4 256 213 0 40 13 0 13 13 0 8 0 art_table 32 214 0 40 2 0 2 2 0 8 0 art_node 16 48 0 10 1 0 1 1 0 8 0 sysvmsgpl 40 6 0 6 2 1 1 1 0 8 1 semupl 112 2 0 2 1 1 0 1 0 8 0 semapl 112 16 0 6 1 0 1 1 0 8 0 shmpl 112 6 0 2 1 0 1 1 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino2pl 256 1727 0 329 88 0 88 88 0 8 0 ffsino 240 1727 0 329 83 0 83 83 0 8 0 nchpl 144 2268 0 666 60 0 60 60 0 8 0 uvmvnodes 72 1847 0 0 34 0 34 34 0 8 0 vnodes 208 1847 0 0 98 0 98 98 0 8 0 namei 1024 5792 0 5792 2 1 1 1 0 8 1 vcpupl 1984 2 0 0 1 0 1 1 0 8 0 vmpool 528 2 0 0 1 0 1 1 0 8 0 pfiaddrpl 120 10 0 6 2 1 1 1 0 8 0 scsiplug 64 1 0 1 1 0 1 1 0 8 1 scxspl 192 6625 0 6625 1 0 1 1 0 8 1 plimitpl 152 30 0 23 1 0 1 1 0 8 0 sigapl 424 439 0 409 4 0 4 4 0 8 0 futexpl 56 5108 0 5108 2 1 1 1 0 8 1 knotepl 112 94 0 75 1 0 1 1 0 8 0 kqueuepl 144 44 0 42 1 0 1 1 0 8 0 pipelkpl 16 88 0 78 1 0 1 1 0 8 0 pipepl 120 176 0 157 1 0 1 1 0 8 0 fdescpl 432 423 0 409 2 0 2 2 0 8 0 filepl 120 2608 0 2513 4 0 4 4 0 8 1 lockfpl 104 43 0 42 1 0 1 1 0 8 0 lockfspl 48 17 0 16 1 0 1 1 0 8 0 sessionpl 112 17 0 7 1 0 1 1 0 8 0 pgrppl 48 21 0 11 1 0 1 1 0 8 0 ucredpl 96 176 0 169 1 0 1 1 0 8 0 zombiepl 144 409 0 409 1 0 1 1 0 8 1 processpl 920 439 0 409 4 0 4 4 0 8 0 procpl 624 711 0 674 5 1 4 4 0 8 0 sosppl 128 5 0 5 1 1 0 1 0 8 0 sockpl 400 881 0 864 8 3 5 5 0 8 3 mcl64k 65536 25 0 25 3 2 1 1 0 8 1 mcl12k 12288 8 0 8 3 2 1 1 0 8 1 mcl9k 9216 9 0 9 3 2 1 1 0 8 1 mcl8k 8192 2 0 2 1 0 1 1 0 8 1 mcl4k 4096 25 0 25 4 3 1 1 0 8 1 mcl2k2 2112 1 0 1 1 1 0 1 0 8 0 mcl2k 2048 75123 0 75067 24 16 8 18 0 8 0 mtagpl 80 34 0 2 2 1 1 1 0 8 0 mbufpl 256 121771 0 121578 30 12 18 20 0 8 5 bufpl 280 3785 0 127 262 0 262 262 0 8 0 anonpl 16 61266 0 45804 81 2 79 79 0 107 13 amapchunkpl 152 2341 0 2215 19 12 7 19 0 158 0 amappl16 192 2297 0 1433 55 1 54 55 0 8 8 amappl15 184 109 0 106 1 0 1 1 0 8 0 amappl14 176 135 0 128 1 0 1 1 0 8 0 amappl13 168 26 0 23 1 0 1 1 0 8 0 amappl12 160 117 0 114 2 1 1 1 0 8 0 amappl11 152 153 0 142 1 0 1 1 0 8 0 amappl10 144 15 0 9 1 0 1 1 0 8 0 amappl9 136 367 0 365 1 0 1 1 0 8 0 amappl8 128 316 0 279 2 0 2 2 0 8 0 amappl7 120 107 0 95 1 0 1 1 0 8 0 amappl6 112 134 0 127 1 0 1 1 0 8 0 amappl5 104 156 0 146 1 0 1 1 0 8 0 amappl4 96 639 0 608 1 0 1 1 0 8 0 amappl3 88 241 0 234 1 0 1 1 0 8 0 amappl2 80 2554 0 2488 2 0 2 2 0 8 0 amappl1 72 17119 0 16710 23 13 10 17 0 8 0 amappl 80 958 0 918 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 7 0 2 1 0 1 1 0 8 0 uaddrrnd 24 425 0 409 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 425 0 409 1 0 1 1 0 8 0 vmmpekpl 168 6660 0 6634 2 0 2 2 0 8 0 vmmpepl 168 57320 0 55378 122 22 100 110 0 357 13 vmsppl 272 424 0 409 3 1 2 2 0 8 0 pdppl 4096 856 0 820 6 1 5 6 0 8 0 pvpl 32 179565 0 161138 189 3 186 186 0 265 31 pmappl 200 424 0 409 1 0 1 1 0 8 0 extentpl 40 53 0 36 1 0 1 1 0 8 0 phpool 112 279 0 43 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(ffffffff823ad659) at panic+0x15c sys/kern/subr_prf.c:207 m_copym(fffffd8053988f00,3ac,b4,2) at m_copym+0x553 sys/kern/uipc_mbuf.c:695 tcp_output(ffff800000ac0760) at tcp_output+0x154d sys/netinet/tcp_output.c:673 tcp_usrreq(fffffd805da71198,9,fffffd8053988e00,0,0,ffff80001d717c40) at tcp_usrreq+0xa54 sosend(fffffd805da71198,0,ffff80001d71edc8,0,0,80) at sosend+0x669 sys/kern/uipc_socket.c:549 dofilewritev(ffff80001d717c40,4,ffff80001d71edc8,0,ffff80001d71eeb0) at dofilewritev+0x1ab sys/kern/sys_generic.c:365 sys_write(ffff80001d717c40,ffff80001d71ee60,ffff80001d71eeb0) at sys_write+0x83 sys/kern/sys_generic.c:285 syscall(ffff80001d71ef30) at syscall+0x507 sys/arch/amd64/amd64/trap.c:570 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7f7ffffc7450, 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(ffffffff823ad659) at panic+0x15c sys/kern/subr_prf.c:207 m_copym(fffffd8053988f00,3ac,b4,2) at m_copym+0x553 sys/kern/uipc_mbuf.c:695 tcp_output(ffff800000ac0760) at tcp_output+0x154d sys/netinet/tcp_output.c:673 tcp_usrreq(fffffd805da71198,9,fffffd8053988e00,0,0,ffff80001d717c40) at tcp_usrreq+0xa54 sosend(fffffd805da71198,0,ffff80001d71edc8,0,0,80) at sosend+0x669 sys/kern/uipc_socket.c:549 dofilewritev(ffff80001d717c40,4,ffff80001d71edc8,0,ffff80001d71eeb0) at dofilewritev+0x1ab sys/kern/sys_generic.c:365 sys_write(ffff80001d717c40,ffff80001d71ee60,ffff80001d71eeb0) at sys_write+0x83 sys/kern/sys_generic.c:285 syscall(ffff80001d71ef30) at syscall+0x507 sys/arch/amd64/amd64/trap.c:570 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7f7ffffc7450, count: -10