panic: m_copym0: short mbuf chain Stopped at db_enter+0x18: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND *404913 7742 0 0x12 0 0 sshd db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:398 panic(ffffffff823c5900) at panic+0x15c sys/kern/subr_prf.c:207 m_copym(fffffd806ad61b00,304,214,2) at m_copym+0x553 sys/kern/uipc_mbuf.c:695 tcp_output(ffff800000ac2320) at tcp_output+0x154d sys/netinet/tcp_output.c:673 tcp_usrreq(fffffd805da71008,9,fffffd806ad61a00,0,0,ffff80001d7179d0) at tcp_usrreq+0xa54 sosend(fffffd805da71008,0,ffff80001d71e018,0,0,80) at sosend+0x669 sys/kern/uipc_socket.c:555 dofilewritev(ffff80001d7179d0,4,ffff80001d71e018,0,ffff80001d71e100) at dofilewritev+0x1ab sys/kern/sys_generic.c:365 sys_write(ffff80001d7179d0,ffff80001d71e0b0,ffff80001d71e100) at sys_write+0x83 sys/kern/sys_generic.c:285 syscall(ffff80001d71e180) at syscall+0x507 sys/arch/amd64/amd64/trap.c:570 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7f7ffffe35f0, 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(ffffffff823c5900) at panic+0x15c sys/kern/subr_prf.c:207 m_copym(fffffd806ad61b00,304,214,2) at m_copym+0x553 sys/kern/uipc_mbuf.c:695 tcp_output(ffff800000ac2320) at tcp_output+0x154d sys/netinet/tcp_output.c:673 tcp_usrreq(fffffd805da71008,9,fffffd806ad61a00,0,0,ffff80001d7179d0) at tcp_usrreq+0xa54 sosend(fffffd805da71008,0,ffff80001d71e018,0,0,80) at sosend+0x669 sys/kern/uipc_socket.c:555 dofilewritev(ffff80001d7179d0,4,ffff80001d71e018,0,ffff80001d71e100) at dofilewritev+0x1ab sys/kern/sys_generic.c:365 sys_write(ffff80001d7179d0,ffff80001d71e0b0,ffff80001d71e100) at sys_write+0x83 sys/kern/sys_generic.c:285 syscall(ffff80001d71e180) at syscall+0x507 sys/arch/amd64/amd64/trap.c:570 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7f7ffffe35f0, count: -10 ddb> show registers rdi 0 rsi 0x1 rbp 0xffff80001d71dae0 rbx 0xffff80001d71db90 rdx 0x2 rcx 0 rax 0x1 r8 0xffffffff810e305f kprintf+0x15f r9 0x1 r10 0x2 r11 0x9779f7c37b425a78 r12 0x3000000008 r13 0xffff80001d71daf0 r14 0x100 r15 0x1 rip 0xffffffff8220f488 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff80001d71dad0 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb> show proc PROC (sshd) pid=404913 stat=onproc flags process=12 proc=0 pri=24, usrpri=50, nice=20 forw=0xffffffffffffffff, list=0xffff80001d718120,0xffff80001d717500 process=0xffff8000ffff8e78 user=0xffff80001d719000, vmspace=0xfffffd806bc0acc0 estcpu=0, cpticks=0, pctcpu=0.0 user=0, sys=0, intr=0 ddb> ps PID TID PPID UID S FLAGS WAIT COMMAND 62589 135783 51406 0 2 0 syz-executor.0 62589 362616 51406 0 2 0x4000000 syz-executor.0 82415 5046 0 0 3 0x14200 bored sosplice 77269 340351 55462 0 2 0x2 syz-executor.1 51406 455429 55462 0 3 0x82 nanosleep syz-executor.0 55462 387620 96919 0 3 0x82 thrsleep syz-fuzzer 55462 242192 96919 0 2 0x4000002 syz-fuzzer 55462 485871 96919 0 2 0x4000002 syz-fuzzer 55462 143872 96919 0 3 0x4000082 thrsleep syz-fuzzer 55462 27981 96919 0 3 0x4000082 thrsleep syz-fuzzer 55462 126920 96919 0 3 0x4000082 thrsleep syz-fuzzer 55462 394850 96919 0 3 0x4000082 thrsleep syz-fuzzer 55462 441954 96919 0 3 0x4000082 thrsleep syz-fuzzer 96919 398006 7742 0 3 0x10008a pause ksh * 7742 404913 81556 0 7 0x12 sshd 6785 172488 1 0 3 0x100083 ttyin getty 81556 412318 1 0 3 0x80 select sshd 29254 314612 30504 73 3 0x100090 kqread syslogd 30504 435245 1 0 3 0x100082 netio syslogd 5746 329774 1 77 3 0x100090 poll dhclient 34541 483446 1 0 3 0x80 poll dhclient 88174 251205 0 0 3 0x14200 bored smr 40593 480404 0 0 2 0x14200 zerothread 65886 83590 0 0 3 0x14200 aiodoned aiodoned 74221 491240 0 0 3 0x14200 syncer update 87400 413698 0 0 3 0x14200 cleaner cleaner 58155 283551 0 0 3 0x14200 reaper reaper 7103 424129 0 0 3 0x14200 pgdaemon pagedaemon 60686 260377 0 0 3 0x14200 bored crynlk 59327 463078 0 0 3 0x14200 bored crypto 71423 381997 0 0 3 0x40014200 acpi0 acpi0 15471 388280 0 0 3 0x14200 bored softnet 26657 30791 0 0 3 0x14200 bored systqmp 81948 462021 0 0 3 0x14200 bored systq 15032 228379 0 0 3 0x40014200 bored softclock 9484 227079 0 0 3 0x40014200 idle0 1 481934 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 9488 6338K 6726K 78643K 10970 0 pcb 13 8K 8K 78643K 97 0 rtable 124 16K 17K 78643K 331 0 ifaddr 68 14K 15K 78643K 113 0 counters 21 16K 16K 78643K 26 0 ioctlops 0 0K 4K 78643K 47 0 iov 0 0K 16K 78643K 55 0 mount 1 1K 1K 78643K 1 0 vnodes 1220 77K 77K 78643K 1341 0 UFS quota 1 32K 32K 78643K 1 0 UFS mount 5 36K 36K 78643K 5 0 shm 2 1K 5K 78643K 3 0 VM map 2 0K 0K 78643K 2 0 sem 12 0K 0K 78643K 44 0 dirhash 12 2K 2K 78643K 12 0 ACPI 1809 195K 288K 78643K 12938 0 file desc 5 13K 25K 78643K 296 0 sigio 0 0K 0K 78643K 4 0 proc 49 38K 54K 78643K 380 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 40 0 in_multi 25 1K 2K 78643K 131 0 ether_multi 1 0K 0K 78643K 16 0 mrt 1 0K 0K 78643K 8 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 122 39K 54K 78643K 1639 0 UVM aobj 6 2K 2K 78643K 6 0 memdesc 1 4K 4K 78643K 1 0 crypto data 1 1K 1K 78643K 1 0 ip6_options 0 0K 0K 78643K 46 0 NDP 10 0K 0K 78643K 26 0 temp 102 3865K 3929K 78643K 13490 0 kqueue 3 4K 12K 78643K 20 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 7 0 0 1 0 1 1 0 8 0 rtpcb 80 29 0 27 1 0 1 1 0 8 0 rtentry 112 66 0 26 2 0 2 2 0 8 0 unpcb 120 133 0 125 1 0 1 1 0 8 0 syncache 264 12 0 12 2 2 0 1 0 8 0 tcpqe 32 54 0 54 2 2 0 1 0 8 0 tcpcb 544 417 0 413 2 1 1 2 0 8 0 inpcb 296 658 0 651 2 0 2 2 0 8 1 rttmr 72 1 0 1 1 1 0 1 0 8 0 nd6 48 17 0 15 1 0 1 1 0 8 0 pfrktable 1344 15 0 4 1 0 1 1 0 8 0 pftag 88 4 0 0 1 0 1 1 0 8 0 pfrule 1360 14 0 4 1 0 1 1 0 8 0 art_heap8 4096 1 0 0 1 0 1 1 0 8 0 art_heap4 256 242 0 80 13 0 13 13 0 8 0 art_table 32 243 0 80 2 0 2 2 0 8 0 art_node 16 65 0 28 1 0 1 1 0 8 0 sysvmsgpl 40 8 0 7 2 1 1 1 0 8 0 semupl 112 1 0 1 1 1 0 1 0 8 0 semapl 112 40 0 30 1 0 1 1 0 8 0 shmpl 112 4 0 0 1 0 1 1 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino2pl 256 1799 0 403 88 0 88 88 0 8 0 ffsino 240 1799 0 403 83 0 83 83 0 8 0 nchpl 144 2394 0 791 60 0 60 60 0 8 0 uvmvnodes 72 1922 0 0 35 0 35 35 0 8 0 vnodes 208 1922 0 0 102 0 102 102 0 8 0 namei 1024 6208 0 6208 1 0 1 1 0 8 1 vcpupl 1984 2 0 0 1 0 1 1 0 8 0 vmpool 528 4 0 2 1 0 1 1 0 8 0 pfiaddrpl 120 8 0 0 1 0 1 1 0 8 0 scxspl 192 7403 0 7403 1 0 1 1 0 8 1 plimitpl 152 33 0 26 1 0 1 1 0 8 0 sigapl 424 483 0 454 4 0 4 4 0 8 0 futexpl 56 6773 0 6773 1 0 1 1 0 8 1 knotepl 112 83 0 64 1 0 1 1 0 8 0 kqueuepl 144 54 0 52 1 0 1 1 0 8 0 pipelkpl 16 96 0 86 1 0 1 1 0 8 0 pipepl 120 192 0 173 1 0 1 1 0 8 0 fdescpl 432 468 0 454 2 0 2 2 0 8 0 filepl 120 2925 0 2830 4 0 4 4 0 8 1 lockfpl 104 67 0 66 1 0 1 1 0 8 0 lockfspl 48 25 0 24 1 0 1 1 0 8 0 sessionpl 112 17 0 7 1 0 1 1 0 8 0 pgrppl 48 19 0 9 1 0 1 1 0 8 0 ucredpl 96 238 0 231 1 0 1 1 0 8 0 zombiepl 144 454 0 454 1 0 1 1 0 8 1 processpl 920 483 0 454 4 0 4 4 0 8 0 procpl 624 916 0 879 4 0 4 4 0 8 0 sosppl 128 2 0 2 1 1 0 1 0 8 0 sockpl 400 822 0 805 3 0 3 3 0 8 1 mcl64k 65536 26 0 26 2 1 1 1 0 8 1 mcl16k 16384 1 0 1 1 1 0 1 0 8 0 mcl12k 12288 10 0 10 3 2 1 1 0 8 1 mcl9k 9216 2 0 2 1 1 0 1 0 8 0 mcl8k 8192 11 0 11 2 1 1 1 0 8 1 mcl4k 4096 30 0 30 3 2 1 1 0 8 1 mcl2k2 2112 1 0 1 1 1 0 1 0 8 0 mcl2k 2048 73966 0 73920 17 10 7 13 0 8 0 mtagpl 96 33 0 2 2 1 1 1 0 8 0 mbufpl 256 119751 0 119452 24 4 20 20 0 8 0 bufpl 280 4094 0 126 284 0 284 284 0 8 0 anonpl 16 60425 0 45222 73 5 68 69 0 107 0 amapchunkpl 152 2667 0 2545 22 12 10 19 0 158 3 amappl16 192 2111 0 1178 49 1 48 48 0 8 1 amappl15 184 1 0 0 1 0 1 1 0 8 0 amappl14 176 165 0 160 1 0 1 1 0 8 0 amappl13 168 26 0 23 1 0 1 1 0 8 0 amappl12 160 278 0 271 1 0 1 1 0 8 0 amappl11 152 51 0 41 1 0 1 1 0 8 0 amappl10 144 12 0 6 1 0 1 1 0 8 0 amappl9 136 367 0 366 1 0 1 1 0 8 0 amappl8 128 335 0 295 2 0 2 2 0 8 0 amappl7 120 106 0 94 1 0 1 1 0 8 0 amappl6 112 26 0 20 1 0 1 1 0 8 0 amappl5 104 541 0 527 1 0 1 1 0 8 0 amappl4 96 421 0 395 1 0 1 1 0 8 0 amappl3 88 121 0 115 1 0 1 1 0 8 0 amappl2 80 3071 0 3002 2 0 2 2 0 8 0 amappl1 72 18144 0 17729 23 13 10 17 0 8 0 amappl 80 1159 0 1120 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 5 0 0 1 0 1 1 0 8 0 uaddrrnd 24 472 0 456 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 472 0 456 1 0 1 1 0 8 0 vmmpekpl 168 7184 0 7157 2 0 2 2 0 8 0 vmmpepl 168 62616 0 60589 123 28 95 115 0 357 2 vmsppl 272 471 0 456 3 1 2 2 0 8 1 pdppl 4096 950 0 914 7 2 5 6 0 8 0 pvpl 32 186316 0 168132 170 4 166 166 0 265 7 pmappl 200 471 0 456 1 0 1 1 0 8 0 extentpl 40 53 0 36 1 0 1 1 0 8 0 phpool 112 260 0 25 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(ffffffff823c5900) at panic+0x15c sys/kern/subr_prf.c:207 m_copym(fffffd806ad61b00,304,214,2) at m_copym+0x553 sys/kern/uipc_mbuf.c:695 tcp_output(ffff800000ac2320) at tcp_output+0x154d sys/netinet/tcp_output.c:673 tcp_usrreq(fffffd805da71008,9,fffffd806ad61a00,0,0,ffff80001d7179d0) at tcp_usrreq+0xa54 sosend(fffffd805da71008,0,ffff80001d71e018,0,0,80) at sosend+0x669 sys/kern/uipc_socket.c:555 dofilewritev(ffff80001d7179d0,4,ffff80001d71e018,0,ffff80001d71e100) at dofilewritev+0x1ab sys/kern/sys_generic.c:365 sys_write(ffff80001d7179d0,ffff80001d71e0b0,ffff80001d71e100) at sys_write+0x83 sys/kern/sys_generic.c:285 syscall(ffff80001d71e180) at syscall+0x507 sys/arch/amd64/amd64/trap.c:570 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7f7ffffe35f0, 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(ffffffff823c5900) at panic+0x15c sys/kern/subr_prf.c:207 m_copym(fffffd806ad61b00,304,214,2) at m_copym+0x553 sys/kern/uipc_mbuf.c:695 tcp_output(ffff800000ac2320) at tcp_output+0x154d sys/netinet/tcp_output.c:673 tcp_usrreq(fffffd805da71008,9,fffffd806ad61a00,0,0,ffff80001d7179d0) at tcp_usrreq+0xa54 sosend(fffffd805da71008,0,ffff80001d71e018,0,0,80) at sosend+0x669 sys/kern/uipc_socket.c:555 dofilewritev(ffff80001d7179d0,4,ffff80001d71e018,0,ffff80001d71e100) at dofilewritev+0x1ab sys/kern/sys_generic.c:365 sys_write(ffff80001d7179d0,ffff80001d71e0b0,ffff80001d71e100) at sys_write+0x83 sys/kern/sys_generic.c:285 syscall(ffff80001d71e180) at syscall+0x507 sys/arch/amd64/amd64/trap.c:570 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7f7ffffe35f0, count: -10