panic: m_copym0: m == NULL and not COPYALL Stopped at db_enter+0x18: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND *457118 66941 0 0x12 0 0 sshd db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:398 panic(ffffffff82404cf3) at panic+0x15c sys/kern/subr_prf.c:207 m_copym(fffffd805c5f5500,2dc,49c,2) at m_copym+0x589 sys/kern/uipc_mbuf.c:664 tcp_output(ffff800000ac0540) at tcp_output+0x154d sys/netinet/tcp_output.c:673 tcp_usrreq(fffffd805da6e4b8,9,fffffd805c5f5400,0,0,ffff80001d7174f0) at tcp_usrreq+0xa54 sosend(fffffd805da6e4b8,0,ffff80001d6ca7a8,0,0,80) at sosend+0x669 sys/kern/uipc_socket.c:549 dofilewritev(ffff80001d7174f0,4,ffff80001d6ca7a8,0,ffff80001d6ca890) at dofilewritev+0x1ab sys/kern/sys_generic.c:365 sys_write(ffff80001d7174f0,ffff80001d6ca840,ffff80001d6ca890) at sys_write+0x83 sys/kern/sys_generic.c:285 syscall(ffff80001d6ca910) at syscall+0x507 sys/arch/amd64/amd64/trap.c:570 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7f7ffffd4090, 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: m == NULL and not COPYALL ddb> trace db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:398 panic(ffffffff82404cf3) at panic+0x15c sys/kern/subr_prf.c:207 m_copym(fffffd805c5f5500,2dc,49c,2) at m_copym+0x589 sys/kern/uipc_mbuf.c:664 tcp_output(ffff800000ac0540) at tcp_output+0x154d sys/netinet/tcp_output.c:673 tcp_usrreq(fffffd805da6e4b8,9,fffffd805c5f5400,0,0,ffff80001d7174f0) at tcp_usrreq+0xa54 sosend(fffffd805da6e4b8,0,ffff80001d6ca7a8,0,0,80) at sosend+0x669 sys/kern/uipc_socket.c:549 dofilewritev(ffff80001d7174f0,4,ffff80001d6ca7a8,0,ffff80001d6ca890) at dofilewritev+0x1ab sys/kern/sys_generic.c:365 sys_write(ffff80001d7174f0,ffff80001d6ca840,ffff80001d6ca890) at sys_write+0x83 sys/kern/sys_generic.c:285 syscall(ffff80001d6ca910) at syscall+0x507 sys/arch/amd64/amd64/trap.c:570 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7f7ffffd4090, count: -10 ddb> show registers rdi 0 rsi 0x1 rbp 0xffff80001d6ca270 rbx 0xffff80001d6ca320 rdx 0x2 rcx 0 rax 0x1 r8 0xffffffff8162e73f kprintf+0x15f r9 0x1 r10 0x2 r11 0x2cb2d422a2cae04c r12 0x3000000008 r13 0xffff80001d6ca280 r14 0x100 r15 0x1 rip 0xffffffff816e5988 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff80001d6ca260 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb> show proc PROC (sshd) pid=457118 stat=onproc flags process=12 proc=0 pri=24, usrpri=50, nice=20 forw=0xffffffffffffffff, list=0xffff80001d718390,0xffff80001d717020 process=0xffff8000ffff8e78 user=0xffff80001d6c5000, 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 57692 317349 34843 0 3 0x80 nanosleep syz-executor.1 57692 59673 34843 0 3 0x4000080 lockf syz-executor.1 57692 110012 34843 0 3 0x4000080 fsleep syz-executor.1 84922 91268 20361 0 2 0x2 syz-executor.0 34843 115292 20361 0 3 0x82 nanosleep syz-executor.1 20361 15696 99993 0 3 0x82 thrsleep syz-fuzzer 20361 11324 99993 0 2 0x4000002 syz-fuzzer 20361 420539 99993 0 3 0x4000082 thrsleep syz-fuzzer 20361 28210 99993 0 3 0x4000082 thrsleep syz-fuzzer 20361 513253 99993 0 2 0x4000002 syz-fuzzer 20361 410577 99993 0 3 0x4000082 thrsleep syz-fuzzer 20361 19915 99993 0 3 0x4000082 thrsleep syz-fuzzer 20361 242140 99993 0 3 0x4000082 thrsleep syz-fuzzer 99993 34943 66941 0 3 0x10008a pause ksh *66941 457118 29720 0 7 0x12 sshd 84543 221089 1 0 3 0x100083 ttyin getty 29720 263533 1 0 3 0x80 select sshd 80325 237937 52089 73 3 0x100090 kqread syslogd 52089 104615 1 0 3 0x100082 netio syslogd 32053 450054 1 77 3 0x100090 poll dhclient 83410 161978 1 0 3 0x80 poll dhclient 78358 114629 0 0 3 0x14200 bored smr 21869 121571 0 0 3 0x14200 pgzero zerothread 17246 332787 0 0 3 0x14200 aiodoned aiodoned 23455 173315 0 0 3 0x14200 syncer update 25381 397678 0 0 3 0x14200 cleaner cleaner 75968 484167 0 0 3 0x14200 reaper reaper 17092 110265 0 0 3 0x14200 pgdaemon pagedaemon 59944 387028 0 0 3 0x14200 bored crynlk 64272 42312 0 0 3 0x14200 bored crypto 13257 32944 0 0 3 0x40014200 acpi0 acpi0 87688 472785 0 0 3 0x14200 bored softnet 33196 314087 0 0 3 0x14200 bored systqmp 30286 469320 0 0 3 0x14200 bored systq 71608 376987 0 0 3 0x40014200 bored softclock 40705 4010 0 0 3 0x40014200 idle0 1 402486 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 9452 6324K 6453K 78643K 10564 0 pcb 13 8K 8K 78643K 21 0 rtable 105 3K 3K 78643K 190 0 ifaddr 41 10K 10K 78643K 45 0 counters 21 16K 16K 78643K 21 0 ioctlops 0 0K 4K 78643K 37 0 iov 0 0K 12K 78643K 2 0 mount 1 1K 1K 78643K 1 0 vnodes 1218 77K 77K 78643K 1229 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 2 0K 0K 78643K 2 0 dirhash 12 2K 2K 78643K 12 0 ACPI 1809 195K 288K 78643K 12938 0 file desc 5 13K 25K 78643K 57 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 1 0 in_multi 40 2K 2K 78643K 42 0 ether_multi 1 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 183 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 124 55K 55K 78643K 998 0 UVM aobj 4 2K 2K 78643K 4 0 memdesc 1 4K 4K 78643K 1 0 crypto data 1 1K 1K 78643K 1 0 ip6_options 0 0K 0K 78643K 8 0 NDP 5 0K 0K 78643K 9 0 temp 61 3839K 3903K 78643K 1971 0 kqueue 3 4K 12K 78643K 7 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 45 0 1 2 0 2 2 0 8 0 unpcb 120 39 0 31 1 0 1 1 0 8 0 syncache 264 6 0 6 2 1 1 1 0 8 1 tcpqe 32 56 0 56 1 0 1 1 0 8 1 tcpcb 544 22 0 18 1 0 1 1 0 8 0 inpcb 280 62 0 55 1 0 1 1 0 8 0 nd6 48 6 0 0 1 0 1 1 0 8 0 pfrule 1360 1 0 0 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 44 0 4 1 0 1 1 0 8 0 shmpl 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 1448 0 50 88 0 88 88 0 8 0 ffsino 240 1448 0 50 83 0 83 83 0 8 0 nchpl 144 1709 0 107 60 0 60 60 0 8 0 uvmvnodes 72 1495 0 0 28 0 28 28 0 8 0 vnodes 208 1495 0 0 79 0 79 79 0 8 0 namei 1024 4278 0 4278 1 0 1 1 0 8 1 vcpupl 1984 16 0 0 2 0 2 2 0 8 0 vmpool 528 16 0 0 2 0 2 2 0 8 0 scxspl 192 4678 0 4678 1 0 1 1 0 8 1 plimitpl 152 14 0 7 1 0 1 1 0 8 0 sigapl 424 243 0 215 4 0 4 4 0 8 0 futexpl 56 574 0 573 1 0 1 1 0 8 0 knotepl 112 66 0 47 1 0 1 1 0 8 0 kqueuepl 144 10 0 8 1 0 1 1 0 8 0 pipelkpl 16 80 0 70 1 0 1 1 0 8 0 pipepl 120 160 0 141 1 0 1 1 0 8 0 fdescpl 432 229 0 215 2 0 2 2 0 8 0 filepl 120 1222 0 1125 4 0 4 4 0 8 1 lockfpl 104 25 0 22 1 0 1 1 0 8 0 lockfspl 48 10 0 8 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 85 0 78 1 0 1 1 0 8 0 zombiepl 144 215 0 215 1 0 1 1 0 8 1 processpl 920 243 0 215 4 0 4 4 0 8 0 procpl 624 286 0 249 4 0 4 4 0 8 1 sockpl 400 120 0 103 3 0 3 3 0 8 1 mcl64k 65536 4 0 4 1 0 1 1 0 8 1 mcl16k 16384 3 0 3 1 0 1 1 0 8 1 mcl12k 12288 1 0 1 1 0 1 1 0 8 1 mcl4k 4096 9 0 9 2 1 1 1 0 8 1 mcl2k 2048 77057 0 77009 15 3 12 13 0 8 4 mtagpl 80 4 0 2 2 1 1 1 0 8 0 mbufpl 256 122043 0 121903 13 3 10 10 0 8 0 bufpl 280 3301 0 126 227 0 227 227 0 8 0 anonpl 16 41734 0 26013 78 1 77 77 0 107 13 amapchunkpl 152 1137 0 1008 8 0 8 8 0 158 1 amappl16 192 1276 0 409 53 1 52 53 0 8 8 amappl15 184 1 0 0 1 0 1 1 0 8 0 amappl14 176 27 0 20 1 0 1 1 0 8 0 amappl13 168 34 0 30 1 0 1 1 0 8 0 amappl12 160 10 0 9 1 0 1 1 0 8 0 amappl11 152 41 0 32 1 0 1 1 0 8 0 amappl10 144 26 0 20 1 0 1 1 0 8 0 amappl9 136 332 0 331 1 0 1 1 0 8 0 amappl8 128 312 0 276 2 0 2 2 0 8 0 amappl7 120 126 0 112 1 0 1 1 0 8 0 amappl6 112 26 0 19 1 0 1 1 0 8 0 amappl5 104 243 0 233 1 0 1 1 0 8 0 amappl4 96 422 0 393 1 0 1 1 0 8 0 amappl3 88 102 0 95 1 0 1 1 0 8 0 amappl2 80 1004 0 939 2 0 2 2 0 8 0 amappl1 72 13792 0 13372 23 8 15 17 0 8 6 amappl 80 526 0 483 2 0 2 2 0 84 1 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 3 0 0 1 0 1 1 0 8 0 uaddrrnd 24 245 0 215 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 245 0 215 1 0 1 1 0 8 0 vmmpekpl 168 5833 0 5803 2 0 2 2 0 8 0 vmmpepl 168 35324 0 33247 116 6 110 110 0 357 18 vmsppl 272 244 0 215 3 0 3 3 0 8 0 pdppl 4096 496 0 446 7 0 7 7 0 8 0 pvpl 32 132902 0 114731 182 0 182 182 0 265 34 pmappl 200 244 0 215 2 0 2 2 0 8 0 extentpl 40 53 0 36 1 0 1 1 0 8 0 phpool 112 241 0 9 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(ffffffff82404cf3) at panic+0x15c sys/kern/subr_prf.c:207 m_copym(fffffd805c5f5500,2dc,49c,2) at m_copym+0x589 sys/kern/uipc_mbuf.c:664 tcp_output(ffff800000ac0540) at tcp_output+0x154d sys/netinet/tcp_output.c:673 tcp_usrreq(fffffd805da6e4b8,9,fffffd805c5f5400,0,0,ffff80001d7174f0) at tcp_usrreq+0xa54 sosend(fffffd805da6e4b8,0,ffff80001d6ca7a8,0,0,80) at sosend+0x669 sys/kern/uipc_socket.c:549 dofilewritev(ffff80001d7174f0,4,ffff80001d6ca7a8,0,ffff80001d6ca890) at dofilewritev+0x1ab sys/kern/sys_generic.c:365 sys_write(ffff80001d7174f0,ffff80001d6ca840,ffff80001d6ca890) at sys_write+0x83 sys/kern/sys_generic.c:285 syscall(ffff80001d6ca910) at syscall+0x507 sys/arch/amd64/amd64/trap.c:570 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7f7ffffd4090, 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(ffffffff82404cf3) at panic+0x15c sys/kern/subr_prf.c:207 m_copym(fffffd805c5f5500,2dc,49c,2) at m_copym+0x589 sys/kern/uipc_mbuf.c:664 tcp_output(ffff800000ac0540) at tcp_output+0x154d sys/netinet/tcp_output.c:673 tcp_usrreq(fffffd805da6e4b8,9,fffffd805c5f5400,0,0,ffff80001d7174f0) at tcp_usrreq+0xa54 sosend(fffffd805da6e4b8,0,ffff80001d6ca7a8,0,0,80) at sosend+0x669 sys/kern/uipc_socket.c:549 dofilewritev(ffff80001d7174f0,4,ffff80001d6ca7a8,0,ffff80001d6ca890) at dofilewritev+0x1ab sys/kern/sys_generic.c:365 sys_write(ffff80001d7174f0,ffff80001d6ca840,ffff80001d6ca890) at sys_write+0x83 sys/kern/sys_generic.c:285 syscall(ffff80001d6ca910) at syscall+0x507 sys/arch/amd64/amd64/trap.c:570 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7f7ffffd4090, count: -10