panic: m_copym0: m == NULL and not COPYALL Stopped at db_enter+0x18: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND * 73134 53955 0 0x12 0 0 sshd db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:398 panic(ffffffff82418adc) at panic+0x15c sys/kern/subr_prf.c:207 m_copym(fffffd8057657000,c4,3e4,2) at m_copym+0x589 sys/kern/uipc_mbuf.c:664 tcp_output(ffff800000ac2100) at tcp_output+0x154d sys/netinet/tcp_output.c:673 tcp_usrreq(fffffd805da6a4b8,9,fffffd805e250000,0,0,ffff80001d7179d0) at tcp_usrreq+0xa54 sosend(fffffd805da6a4b8,0,ffff80001d6ca518,0,0,80) at sosend+0x669 sys/kern/uipc_socket.c:555 dofilewritev(ffff80001d7179d0,4,ffff80001d6ca518,0,ffff80001d6ca600) at dofilewritev+0x1ab sys/kern/sys_generic.c:365 sys_write(ffff80001d7179d0,ffff80001d6ca5b0,ffff80001d6ca600) at sys_write+0x83 sys/kern/sys_generic.c:285 syscall(ffff80001d6ca680) at syscall+0x507 sys/arch/amd64/amd64/trap.c:570 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7f7ffffeb650, 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(ffffffff82418adc) at panic+0x15c sys/kern/subr_prf.c:207 m_copym(fffffd8057657000,c4,3e4,2) at m_copym+0x589 sys/kern/uipc_mbuf.c:664 tcp_output(ffff800000ac2100) at tcp_output+0x154d sys/netinet/tcp_output.c:673 tcp_usrreq(fffffd805da6a4b8,9,fffffd805e250000,0,0,ffff80001d7179d0) at tcp_usrreq+0xa54 sosend(fffffd805da6a4b8,0,ffff80001d6ca518,0,0,80) at sosend+0x669 sys/kern/uipc_socket.c:555 dofilewritev(ffff80001d7179d0,4,ffff80001d6ca518,0,ffff80001d6ca600) at dofilewritev+0x1ab sys/kern/sys_generic.c:365 sys_write(ffff80001d7179d0,ffff80001d6ca5b0,ffff80001d6ca600) at sys_write+0x83 sys/kern/sys_generic.c:285 syscall(ffff80001d6ca680) at syscall+0x507 sys/arch/amd64/amd64/trap.c:570 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7f7ffffeb650, count: -10 ddb> show registers rdi 0 rsi 0x1 rbp 0xffff80001d6c9fe0 rbx 0xffff80001d6ca090 rdx 0x2 rcx 0 rax 0x1 r8 0xffffffff81b719cf kprintf+0x15f r9 0x1 r10 0x2 r11 0xd0eab27eb961faac r12 0x3000000008 r13 0xffff80001d6c9ff0 r14 0x100 r15 0x1 rip 0xffffffff81845b08 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff80001d6c9fd0 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb> show proc PROC (sshd) pid=73134 stat=onproc flags process=12 proc=0 pri=24, usrpri=50, nice=20 forw=0xffffffffffffffff, list=0xffff80001d718870,0xffff80001d717500 process=0xffff8000ffff8ae0 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 57967 256936 11427 0 2 0x482 syz-executor.0 52698 386802 11427 0 2 0x2 syz-executor.1 11427 204770 53803 0 3 0x82 thrsleep syz-fuzzer 11427 401406 53803 0 2 0x4000482 syz-fuzzer 11427 389797 53803 0 2 0x4000002 syz-fuzzer 11427 82317 53803 0 3 0x4000082 thrsleep syz-fuzzer 11427 480395 53803 0 3 0x4000082 thrsleep syz-fuzzer 11427 290425 53803 0 3 0x4000082 thrsleep syz-fuzzer 11427 102876 53803 0 3 0x4000082 thrsleep syz-fuzzer 11427 371354 53803 0 3 0x4000082 thrsleep syz-fuzzer 53803 351937 53955 0 3 0x10008a pause ksh *53955 73134 34949 0 7 0x12 sshd 94784 330314 1 0 3 0x100083 ttyin getty 34949 511095 1 0 3 0x80 select sshd 34024 283628 37547 73 3 0x100090 kqread syslogd 37547 419124 1 0 3 0x100082 netio syslogd 715 65690 1 77 3 0x100090 poll dhclient 11367 271352 1 0 3 0x80 poll dhclient 38152 193184 0 0 3 0x14200 bored smr 45806 422535 0 0 3 0x14200 pgzero zerothread 19847 74851 0 0 3 0x14200 aiodoned aiodoned 9885 344692 0 0 3 0x14200 syncer update 10608 399388 0 0 3 0x14200 cleaner cleaner 33115 329759 0 0 3 0x14200 reaper reaper 56466 328317 0 0 3 0x14200 pgdaemon pagedaemon 72164 150218 0 0 3 0x14200 bored crynlk 15180 274120 0 0 3 0x14200 bored crypto 65296 478313 0 0 3 0x40014200 acpi0 acpi0 21660 455128 0 0 3 0x14200 bored softnet 93828 431379 0 0 3 0x14200 bored systqmp 27405 52612 0 0 3 0x14200 bored systq 18811 210546 0 0 3 0x40014200 bored softclock 5400 228654 0 0 3 0x40014200 idle0 1 107345 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 9483 6462K 7044K 78643K 10854 0 pcb 13 8K 8K 78643K 54 0 rtable 114 4K 7K 78643K 245 0 ifaddr 60 13K 14K 78643K 75 0 counters 21 16K 16K 78643K 21 0 ioctlops 0 0K 4K 78643K 33 0 iov 0 0K 12K 78643K 21 0 mount 1 1K 1K 78643K 1 0 vnodes 1219 77K 77K 78643K 1308 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 12 1K 1K 78643K 24 0 dirhash 12 2K 2K 78643K 12 0 ACPI 1809 195K 288K 78643K 12938 0 file desc 4 9K 25K 78643K 154 0 sigio 0 0K 0K 78643K 8 0 proc 48 38K 54K 78643K 372 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 6 0 in_multi 46 2K 2K 78643K 63 0 ether_multi 1 0K 0K 78643K 3 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 193 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 125 39K 39K 78643K 1180 0 UVM aobj 12 4K 4K 78643K 12 0 memdesc 1 4K 4K 78643K 1 0 crypto data 1 1K 1K 78643K 1 0 ip6_options 0 0K 0K 78643K 28 0 NDP 8 0K 0K 78643K 14 0 temp 81 3860K 3932K 78643K 6346 0 kqueue 3 4K 10K 78643K 13 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 21 0 19 1 0 1 1 0 8 0 rtentry 112 49 0 4 2 0 2 2 0 8 0 unpcb 120 61 0 53 1 0 1 1 0 8 0 syncache 264 4 0 4 1 1 0 1 0 8 0 sackhl 24 1 0 1 1 0 1 1 0 8 1 tcpcb 544 48 0 44 1 0 1 1 0 8 0 ipq 40 4 0 4 1 0 1 1 0 8 1 ipqe 40 10 0 10 1 0 1 1 0 8 1 inpcb 296 378 0 371 2 0 2 2 0 8 1 rttmr 72 1 0 1 1 0 1 1 0 8 1 nd6 48 9 0 2 1 0 1 1 0 8 0 pkpcb 40 4 0 4 1 0 1 1 0 8 1 pfrktable 1344 19 0 16 1 0 1 1 0 8 0 pftag 88 4 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 256 190 0 0 12 0 12 12 0 8 0 art_table 32 191 0 0 2 0 2 2 0 8 0 art_node 16 48 0 7 1 0 1 1 0 8 0 sysvmsgpl 40 2 0 0 1 0 1 1 0 8 0 semupl 112 2 0 2 1 0 1 1 0 8 1 semapl 112 16 0 6 1 0 1 1 0 8 0 shmpl 112 10 0 0 1 0 1 1 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino2pl 256 1586 0 189 88 0 88 88 0 8 0 ffsino 240 1586 0 189 83 0 83 83 0 8 0 nchpl 144 1973 0 370 60 0 60 60 0 8 0 uvmvnodes 72 1697 0 0 31 0 31 31 0 8 0 vnodes 208 1697 0 0 90 0 90 90 0 8 0 namei 1024 5066 0 5066 2 1 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 6 1 0 1 1 0 8 0 scsiplug 64 1 0 1 1 0 1 1 0 8 1 scxspl 192 5901 0 5901 1 0 1 1 0 8 1 plimitpl 152 32 0 25 1 0 1 1 0 8 0 sigapl 424 340 0 313 4 0 4 4 0 8 0 futexpl 56 3043 0 3043 2 1 1 1 0 8 1 knotepl 112 79 0 60 1 0 1 1 0 8 0 kqueuepl 144 24 0 22 1 0 1 1 0 8 0 pipepl 272 86 0 76 1 0 1 1 0 8 0 fdescpl 432 326 0 313 2 0 2 2 0 8 0 filepl 120 1941 0 1846 4 0 4 4 0 8 1 lockfpl 104 45 0 44 1 0 1 1 0 8 0 lockfspl 48 18 0 17 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 96 170 0 163 1 0 1 1 0 8 0 zombiepl 144 313 0 312 1 0 1 1 0 8 0 processpl 920 340 0 312 4 0 4 4 0 8 0 procpl 624 487 0 452 4 0 4 4 0 8 1 sockpl 400 464 0 447 5 1 4 4 0 8 2 mcl64k 65536 8 0 8 1 0 1 1 0 8 1 mcl12k 12288 3 0 3 1 0 1 1 0 8 1 mcl9k 9216 1 0 1 1 0 1 1 0 8 1 mcl8k 8192 5 0 5 1 0 1 1 0 8 1 mcl4k 4096 22 0 22 2 1 1 1 0 8 1 mcl2k2 2112 3 0 3 1 0 1 1 0 8 1 mcl2k 2048 70273 0 70229 14 7 7 12 0 8 1 mtagpl 96 32 0 2 2 1 1 1 0 8 0 mbufpl 256 112401 0 112209 14 1 13 13 0 8 0 bufpl 280 3633 0 127 251 0 251 251 0 8 0 anonpl 16 46115 0 30580 68 2 66 66 0 107 0 amapchunkpl 152 1365 0 1226 8 1 7 8 0 158 0 amappl16 192 1540 0 671 46 0 46 46 0 8 2 amappl15 184 57 0 55 1 0 1 1 0 8 0 amappl14 176 24 0 19 1 0 1 1 0 8 0 amappl13 168 29 0 24 1 0 1 1 0 8 0 amappl12 160 77 0 74 1 0 1 1 0 8 0 amappl11 152 57 0 47 1 0 1 1 0 8 0 amappl10 144 70 0 65 1 0 1 1 0 8 0 amappl9 136 375 0 374 1 0 1 1 0 8 0 amappl8 128 331 0 286 2 0 2 2 0 8 0 amappl7 120 105 0 94 1 0 1 1 0 8 0 amappl6 112 25 0 18 1 0 1 1 0 8 0 amappl5 104 323 0 312 1 0 1 1 0 8 0 amappl4 96 419 0 391 1 0 1 1 0 8 0 amappl3 88 103 0 98 1 0 1 1 0 8 0 amappl2 80 1840 0 1782 2 0 2 2 0 8 0 amappl1 72 15671 0 15268 23 14 9 17 0 8 0 amappl 80 708 0 667 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 11 0 0 1 0 1 1 0 8 0 uaddrrnd 24 330 0 315 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 330 0 315 1 0 1 1 0 8 0 vmmpekpl 168 6262 0 6234 2 0 2 2 0 8 0 vmmpepl 168 45842 0 43974 120 13 107 115 0 357 21 vmsppl 272 329 0 315 2 0 2 2 0 8 1 pdppl 4096 666 0 632 6 0 6 6 0 8 1 pvpl 32 153191 0 134762 163 2 161 161 0 265 7 pmappl 200 329 0 315 1 0 1 1 0 8 0 extentpl 40 53 0 36 1 0 1 1 0 8 0 phpool 112 243 0 13 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(ffffffff82418adc) at panic+0x15c sys/kern/subr_prf.c:207 m_copym(fffffd8057657000,c4,3e4,2) at m_copym+0x589 sys/kern/uipc_mbuf.c:664 tcp_output(ffff800000ac2100) at tcp_output+0x154d sys/netinet/tcp_output.c:673 tcp_usrreq(fffffd805da6a4b8,9,fffffd805e250000,0,0,ffff80001d7179d0) at tcp_usrreq+0xa54 sosend(fffffd805da6a4b8,0,ffff80001d6ca518,0,0,80) at sosend+0x669 sys/kern/uipc_socket.c:555 dofilewritev(ffff80001d7179d0,4,ffff80001d6ca518,0,ffff80001d6ca600) at dofilewritev+0x1ab sys/kern/sys_generic.c:365 sys_write(ffff80001d7179d0,ffff80001d6ca5b0,ffff80001d6ca600) at sys_write+0x83 sys/kern/sys_generic.c:285 syscall(ffff80001d6ca680) at syscall+0x507 sys/arch/amd64/amd64/trap.c:570 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7f7ffffeb650, 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(ffffffff82418adc) at panic+0x15c sys/kern/subr_prf.c:207 m_copym(fffffd8057657000,c4,3e4,2) at m_copym+0x589 sys/kern/uipc_mbuf.c:664 tcp_output(ffff800000ac2100) at tcp_output+0x154d sys/netinet/tcp_output.c:673 tcp_usrreq(fffffd805da6a4b8,9,fffffd805e250000,0,0,ffff80001d7179d0) at tcp_usrreq+0xa54 sosend(fffffd805da6a4b8,0,ffff80001d6ca518,0,0,80) at sosend+0x669 sys/kern/uipc_socket.c:555 dofilewritev(ffff80001d7179d0,4,ffff80001d6ca518,0,ffff80001d6ca600) at dofilewritev+0x1ab sys/kern/sys_generic.c:365 sys_write(ffff80001d7179d0,ffff80001d6ca5b0,ffff80001d6ca600) at sys_write+0x83 sys/kern/sys_generic.c:285 syscall(ffff80001d6ca680) at syscall+0x507 sys/arch/amd64/amd64/trap.c:570 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7f7ffffeb650, count: -10