panic: tcp_output Stopped at db_enter+0x18: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND *419601 40872 0 0 0x4000000 0 syz-executor.0 db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:437 panic(ffffffff82550c9e) at panic+0x161 sys/kern/subr_prf.c:198 tcp_output(ffff800000e47598) at tcp_output+0x2a72 sys/netinet/tcp_output.c:727 tcp_send(fffffd8077106668,fffffd8064ec8900,0,fffffd8064ec8f00) at tcp_send+0xc4 sys/netinet/tcp_usrreq.c:944 sosend(fffffd8077106668,0,ffff80002b4e1140,0,fffffd8064ec8f00,0) at sosend+0x62a pru_send sys/sys/protosw.h:331 [inline] sosend(fffffd8077106668,0,ffff80002b4e1140,0,fffffd8064ec8f00,0) at sosend+0x62a sys/kern/uipc_socket.c:646 sendit(ffff8000216f0540,9,ffff80002b4e12c0,0,ffff80002b4e13c0) at sendit+0x64d sys/kern/uipc_syscalls.c:694 sys_sendmsg(ffff8000216f0540,ffff80002b4e1368,ffff80002b4e13c0) at sys_sendmsg+0x198 sys/kern/uipc_syscalls.c:601 syscall(ffff80002b4e1430) at syscall+0x447 sys/arch/amd64/amd64/trap.c:585 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x6c960ab7670, count: 6 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 *cpu0: tcp_output ddb> trace db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:437 panic(ffffffff82550c9e) at panic+0x161 sys/kern/subr_prf.c:198 tcp_output(ffff800000e47598) at tcp_output+0x2a72 sys/netinet/tcp_output.c:727 tcp_send(fffffd8077106668,fffffd8064ec8900,0,fffffd8064ec8f00) at tcp_send+0xc4 sys/netinet/tcp_usrreq.c:944 sosend(fffffd8077106668,0,ffff80002b4e1140,0,fffffd8064ec8f00,0) at sosend+0x62a pru_send sys/sys/protosw.h:331 [inline] sosend(fffffd8077106668,0,ffff80002b4e1140,0,fffffd8064ec8f00,0) at sosend+0x62a sys/kern/uipc_socket.c:646 sendit(ffff8000216f0540,9,ffff80002b4e12c0,0,ffff80002b4e13c0) at sendit+0x64d sys/kern/uipc_syscalls.c:694 sys_sendmsg(ffff8000216f0540,ffff80002b4e1368,ffff80002b4e13c0) at sys_sendmsg+0x198 sys/kern/uipc_syscalls.c:601 syscall(ffff80002b4e1430) at syscall+0x447 sys/arch/amd64/amd64/trap.c:585 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x6c960ab7670, count: -9 ddb> show registers rdi 0 rsi 0x1 rbp 0xffff80002b4e0db0 rbx 0x7c rdx 0xffff800000c12bc0 rcx 0 rax 0xffff8000216f0540 r8 0x101010101010101 r9 0x8080808080808080 r10 0x6759ab7841e1dfbc r11 0x8ac85ee3bdb84285 r12 0 r13 0 r14 0 r15 0x1 rip 0xffffffff81685218 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff80002b4e0da0 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb> show proc PROC (syz-executor.0) pid=419601 stat=onproc flags process=0 proc=4000000 pri=32, usrpri=83, nice=20 forw=0xffffffffffffffff, list=0xffff8000216f0d20,0xffff80002b4c2fe0 process=0xffff8000280513c0 user=0xffff80002b4dc000, vmspace=0xfffffd80786c3010 estcpu=33, cpticks=0, pctcpu=0.0 user=0, sys=0, intr=0 ddb> ps PID TID PPID UID S FLAGS WAIT COMMAND 59466 24413 36617 0 3 0x80 nanoslp syz-executor.4 59466 26352 36617 0 3 0x4000080 fsleep syz-executor.4 63377 217078 39625 0 2 0 syz-executor.6 63377 449513 39625 0 3 0x4000080 fsleep syz-executor.6 40490 192076 92517 0 3 0x80 nanoslp syz-executor.5 40490 92153 92517 0 3 0x4000080 netcon2 syz-executor.5 40490 355577 92517 0 3 0x4000080 fsleep syz-executor.5 40490 224043 92517 0 3 0x4000080 fsleep syz-executor.5 28167 169237 97130 0 2 0 syz-executor.2 28167 42037 97130 0 3 0x4000080 fsleep syz-executor.2 40872 369392 75756 0 2 0 syz-executor.0 *40872 419601 75756 0 7 0x4000000 syz-executor.0 97130 285280 50085 0 3 0x82 nanoslp syz-executor.2 30610 63269 1 0 3 0x100083 ttyin getty 94378 315088 50085 0 3 0x82 nanoslp syz-executor.3 81767 401962 50085 0 3 0x82 nanoslp syz-executor.7 92517 431609 50085 0 3 0x82 nanoslp syz-executor.5 75756 491131 50085 0 3 0x82 nanoslp syz-executor.0 58606 190207 50085 0 2 0x2 syz-executor.1 39625 252811 50085 0 3 0x82 nanoslp syz-executor.6 36617 295877 50085 0 3 0x82 nanoslp syz-executor.4 36442 296904 0 0 3 0x14200 acct acct 88832 418273 0 0 3 0x14200 bored sosplice 35409 288873 0 0 3 0x14280 nfsidl nfsio 23723 46718 0 0 3 0x14280 nfsidl nfsio 55916 354190 0 0 3 0x14280 nfsidl nfsio 57490 458683 0 0 3 0x14280 nfsidl nfsio 4163 105902 0 0 3 0x14280 nfsidl nfsio 35385 516224 0 0 3 0x14280 nfsidl nfsio 48648 133102 0 0 3 0x14280 nfsidl nfsio 48616 465339 0 0 3 0x14280 nfsidl nfsio 14218 281995 0 0 3 0x14280 nfsidl nfsio 34379 507467 0 0 3 0x14280 nfsidl nfsio 64914 38182 0 0 3 0x14280 nfsidl nfsio 87677 236719 0 0 3 0x14280 nfsidl nfsio 77512 346230 0 0 3 0x14280 nfsidl nfsio 22822 53525 0 0 3 0x14280 nfsidl nfsio 50468 506596 0 0 3 0x14280 nfsidl nfsio 91571 215960 0 0 3 0x14280 nfsidl nfsio 98147 424968 0 0 3 0x14280 nfsidl nfsio 22943 311981 0 0 3 0x14280 nfsidl nfsio 91651 200606 0 0 3 0x14280 nfsidl nfsio 98293 250161 0 0 3 0x14280 nfsidl nfsio 50085 405100 273 0 3 0x82 kqread syz-fuzzer 50085 121406 273 0 3 0x4000082 nanoslp syz-fuzzer 50085 86329 273 0 3 0x4000082 wait syz-fuzzer 50085 337854 273 0 3 0x4000082 thrsleep syz-fuzzer 50085 255217 273 0 3 0x4000082 wait syz-fuzzer 50085 515901 273 0 3 0x4000082 thrsleep syz-fuzzer 50085 283028 273 0 3 0x4000082 thrsleep syz-fuzzer 50085 429549 273 0 3 0x4000082 thrsleep syz-fuzzer 50085 419847 273 0 3 0x4000082 wait syz-fuzzer 50085 95884 273 0 3 0x4000082 wait syz-fuzzer 50085 232323 273 0 3 0x4000082 wait syz-fuzzer 50085 125737 273 0 3 0x4000082 wait syz-fuzzer 50085 117029 273 0 3 0x4000082 wait syz-fuzzer 50085 395177 273 0 3 0x4000082 wait syz-fuzzer 50085 313952 273 0 3 0x4000082 thrsleep syz-fuzzer 273 183616 56040 0 3 0x10008a sigsusp ksh 56040 434249 23180 0 3 0x9a kqread sshd 23180 235795 1 0 3 0x88 kqread sshd 65908 214281 21656 73 3 0x1100090 kqread syslogd 21656 183857 1 0 3 0x100082 netio syslogd 84913 245356 1 0 3 0x100080 kqread resolvd 70782 35373 68900 77 3 0x100092 kqread dhcpleased 85367 50291 68900 77 3 0x100092 kqread dhcpleased 68900 271225 1 0 3 0x80 kqread dhcpleased 27989 440834 0 0 3 0x14200 bored smr 27021 405917 0 0 2 0x14200 zerothread 61517 412384 0 0 3 0x14200 aiodoned aiodoned 46164 101293 0 0 3 0x14200 syncer update 73323 328130 0 0 3 0x14200 cleaner cleaner 55254 145297 0 0 3 0x14200 reaper reaper 95103 334294 0 0 3 0x14200 pgdaemon pagedaemon 49266 338379 0 0 3 0x14200 bored viomb 60548 59311 0 0 3 0x40014200 acpi0 acpi0 15287 398871 0 0 3 0x14200 bored softnet 24119 475304 0 0 3 0x14200 bored softnet 24831 145933 0 0 3 0x14200 bored softnet 31171 122515 0 0 3 0x14200 bored softnet 21153 240669 0 0 3 0x14200 bored systqmp 34917 95538 0 0 3 0x14200 bored systq 76794 341372 0 0 3 0x40014200 bored softclock 95143 403977 0 0 3 0x40014200 idle0 1 324700 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 10220 6565K 7082K 78643K 29667 0 pcb 13 22K 26K 78643K 1406 0 rtable 215 12K 14K 78643K 3198 0 ifaddr 93 21K 22K 78643K 1664 0 sysctl 3 1K 1K 78643K 38 0 counters 27 17K 17K 78643K 199 0 ioctlops 0 0K 4K 78643K 2278 0 iov 0 0K 32K 78643K 1020 0 mount 1 1K 1K 78643K 1 0 log 0 0K 0K 78643K 4 0 vnodes 1401 88K 88K 78643K 7111 0 UFS quota 1 32K 32K 78643K 1 0 UFS mount 5 36K 36K 78643K 5 0 shm 2 1K 5K 78643K 80 0 VM map 2 0K 0K 78643K 2 0 sem 23 10K 20K 78643K 925 0 dirhash 12 2K 2K 78643K 12 0 ACPI 1697 195K 286K 78643K 12548 0 file desc 15 53K 77K 78643K 10292 0 sigio 0 0K 0K 78643K 336 0 proc 67 59K 83K 78643K 1802 0 subproc 104 6K 6K 78643K 559 0 NFS srvsock 1 0K 0K 78643K 1 0 NFS daemon 1 16K 16K 78643K 1 0 ip_moptions 0 0K 0K 78643K 262 0 in_multi 87 6K 6K 78643K 752 0 ether_multi 1 0K 0K 78643K 40 0 mrt 1 0K 0K 78643K 25 0 ISOFS mount 1 32K 32K 78643K 1 0 MSDOSFS mount 1 16K 16K 78643K 1 0 ttys 235 1049K 1049K 78643K 235 0 exec 0 0K 2K 78643K 2537 0 pfkey data 0 0K 0K 78643K 75 0 tdb 3 0K 0K 78643K 3 0 pagedep 1 8K 8K 78643K 1 0 inodedep 1 32K 32K 78643K 1 0 newblk 1 0K 0K 78643K 1 0 VM swap 8 62K 62K 78643K 8 0 UVM amap 409 755K 761K 78643K 57180 0 UVM aobj 131 4K 4K 78643K 140 0 memdesc 1 4K 4K 78643K 1 0 crypto data 1 1K 1K 78643K 1 0 ip6_options 0 0K 0K 78643K 265 0 NDP 14 0K 2K 78643K 252 0 temp 136 4718K 66413K 78643K 115481 0 kqueue 12 18K 26K 78643K 831 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 rtpcb 120 692 0 689 11 8 3 3 0 8 2 rtentry 112 762 0 671 4 1 3 4 0 8 0 unpcb 144 20795 0 20767 162 160 2 10 0 8 0 syncache 296 44 0 44 11 11 0 1 0 8 0 tcpqe 32 180 0 180 7 7 0 1 0 8 0 tcpcb 768 3938 0 3920 173 171 2 28 0 8 0 arp 88 103 0 87 1 0 1 1 0 8 0 ipq 40 76 0 76 7 6 1 1 0 8 1 ipqe 40 156 0 156 7 6 1 1 0 8 1 inpcb 336 14387 0 14361 162 158 4 18 0 8 1 ip6q 72 5 0 4 2 1 1 1 0 8 0 ip6af 40 9 0 8 2 1 1 1 0 8 0 nd6 48 167 0 146 1 0 1 1 0 8 0 pkpcb 40 83 0 83 9 9 0 1 0 8 0 kcovpl 48 43 0 35 1 0 1 1 0 8 0 ppxss 1160 109 0 109 14 13 1 1 0 8 1 pfstscr 40 28 0 26 4 3 1 1 0 8 0 pfosfp 40 5 0 5 1 1 0 1 0 8 0 pfosfpen 112 5 0 5 1 1 0 1 0 8 0 pfrktable 1344 482 0 482 11 10 1 1 0 8 1 pfanchor 1280 590 491 78 43 0 43 43 0 8 0 pftag 88 58 0 51 1 0 1 1 0 8 0 pfqueue 264 3 0 3 1 1 0 1 0 8 0 pfstitem 24 2 0 0 1 0 1 1 0 8 0 pfstkey 120 25 0 23 4 3 1 1 0 8 0 pfstate 336 17 0 16 4 3 1 1 0 8 0 pfrule 1360 539 0 539 21 20 1 1 0 8 1 art_heap8 4096 12 0 11 8 7 1 3 0 8 0 art_heap4 256 3596 0 3193 54 27 27 32 0 8 0 art_table 32 3608 0 3204 7 3 4 5 0 8 0 art_node 16 761 0 681 1 0 1 1 0 8 0 sysvmsgpl 40 36 0 12 1 0 1 1 0 8 0 semupl 112 15 0 15 1 1 0 1 0 8 0 semapl 112 159 0 138 1 0 1 1 0 8 0 shmpl 112 137 0 9 4 0 4 4 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino2pl 256 16064 0 14598 93 1 92 92 0 8 0 ffsino 240 16064 0 14598 87 0 87 87 0 8 0 nchpl 144 30093 0 28460 63 1 62 63 0 8 0 rtmask 32 7 0 7 3 3 0 1 0 8 0 uvmvnodes 80 5926 0 0 121 0 121 121 0 8 0 vnodes 216 5926 0 0 330 0 330 330 0 8 0 namei 1024 103255 0 103255 3 2 1 2 0 8 1 vcpupl 2048 109 0 0 14 0 14 14 0 8 0 vmpool 536 135 0 26 8 0 8 8 0 8 0 pfiaddrpl 120 377 0 377 12 11 1 1 0 8 1 kstatmem 264 288 0 260 3 0 3 3 0 8 1 scxspl 216 89446 0 89446 22 21 1 8 0 8 1 plimitpl 152 1406 0 1392 1 0 1 1 0 8 0 sigapl 424 10533 0 10467 9 1 8 8 0 8 0 futexpl 64 106641 0 106636 1 0 1 1 0 8 0 knotepl 120 138829 0 138749 66 61 5 10 0 8 0 kqueuepl 184 2045 0 2037 24 23 1 4 0 8 0 pipepl 288 2833 0 2805 65 62 3 11 0 8 0 fdescpl 432 10495 0 10469 5 1 4 4 0 8 0 filepl 120 85557 0 85286 147 136 11 17 0 8 2 lockfpl 104 2951 0 2949 11 10 1 2 0 8 0 lockfspl 48 751 0 749 1 0 1 1 0 8 0 sessionpl 144 60 0 44 1 0 1 1 0 8 0 pgrppl 48 109 0 93 1 0 1 1 0 8 0 ucredpl 104 8221 0 8210 1 0 1 1 0 8 0 zombiepl 144 10469 0 10467 2 1 1 1 0 8 0 processpl 1000 10533 0 10467 12 3 9 9 0 8 0 procpl 672 26214 0 26127 38 30 8 10 0 8 0 sosppl 168 109 0 108 16 15 1 1 0 8 0 sockpl 456 35960 0 35903 942 931 11 42 0 8 3 mcl64k 65536 413 0 413 26 25 1 1 0 8 1 mcl16k 16384 148 0 148 26 26 0 1 0 8 0 mcl12k 12288 290 0 290 25 24 1 1 0 8 1 mcl9k 9216 130 0 130 22 21 1 1 0 8 1 mcl8k 8192 501 0 501 17 16 1 1 0 8 1 mcl4k 4096 1241 0 1241 8 7 1 1 0 8 1 mcl2k2 2112 311 0 311 24 23 1 1 0 8 1 mcl2k 2048 90518 0 90453 38 28 10 22 0 8 0 mtagpl 96 1937 0 1757 19 13 6 10 0 8 0 mbufpl 256 222964 0 222569 108 75 33 63 0 8 0 bufpl 288 19712 0 13311 458 0 458 458 0 8 0 anonpl 24 2032753 0 2015805 288 175 113 187 0 188 0 amapchunkpl 152 171817 0 171146 132 101 31 60 0 158 0 amappl16 200 28623 0 27972 139 101 38 47 0 8 0 amappl15 192 1805 0 1798 1 0 1 1 0 8 0 amappl14 184 1385 0 1378 1 0 1 1 0 8 0 amappl13 176 888 0 887 1 0 1 1 0 8 0 amappl12 168 575 0 572 1 0 1 1 0 8 0 amappl11 160 1575 0 1555 3 1 2 2 0 8 1 amappl10 152 1497 0 1488 1 0 1 1 0 8 0 amappl9 144 1505 0 1498 1 0 1 1 0 8 0 amappl8 136 3899 0 3800 5 1 4 4 0 8 0 amappl7 128 2845 0 2822 1 0 1 1 0 8 0 amappl6 120 1452 0 1433 2 1 1 2 0 8 0 amappl5 112 9462 0 9447 1 0 1 1 0 8 0 amappl4 104 4359 0 4324 7 5 2 2 0 8 0 amappl3 96 30735 0 30685 3 1 2 2 0 8 0 amappl2 88 1725 0 1688 2 0 2 2 0 8 0 amappl1 80 256746 0 256112 22 7 15 19 0 8 0 amappl 88 55802 0 55601 7 1 6 6 0 92 1 dma4096 4096 1 0 1 1 1 0 1 0 8 0 dma1024 1024 1 0 0 1 0 1 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 72 139 0 9 3 0 3 3 0 8 0 uaddrrnd 24 10630 0 10495 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 10630 0 10495 1 0 1 1 0 8 0 vmmpekpl 168 77623 0 77546 4 0 4 4 0 8 0 vmmpepl 168 1021621 0 1018841 386 225 161 161 0 357 20 vmsppl 272 10629 0 10495 12 2 10 10 0 8 0 rwobjpl 24 247572 0 239806 52 4 48 48 0 8 0 pdppl 4096 21266 0 21099 672 499 173 173 0 8 6 pvpl 32 3916349 0 3895409 529 343 186 310 0 265 0 pmappl 216 10629 0 10495 10 2 8 8 0 8 0 extentpl 40 56 0 38 1 0 1 1 0 8 0 phpool 112 1882 0 960 28 0 28 28 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:437 panic(ffffffff82550c9e) at panic+0x161 sys/kern/subr_prf.c:198 tcp_output(ffff800000e47598) at tcp_output+0x2a72 sys/netinet/tcp_output.c:727 tcp_send(fffffd8077106668,fffffd8064ec8900,0,fffffd8064ec8f00) at tcp_send+0xc4 sys/netinet/tcp_usrreq.c:944 sosend(fffffd8077106668,0,ffff80002b4e1140,0,fffffd8064ec8f00,0) at sosend+0x62a pru_send sys/sys/protosw.h:331 [inline] sosend(fffffd8077106668,0,ffff80002b4e1140,0,fffffd8064ec8f00,0) at sosend+0x62a sys/kern/uipc_socket.c:646 sendit(ffff8000216f0540,9,ffff80002b4e12c0,0,ffff80002b4e13c0) at sendit+0x64d sys/kern/uipc_syscalls.c:694 sys_sendmsg(ffff8000216f0540,ffff80002b4e1368,ffff80002b4e13c0) at sys_sendmsg+0x198 sys/kern/uipc_syscalls.c:601 syscall(ffff80002b4e1430) at syscall+0x447 sys/arch/amd64/amd64/trap.c:585 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x6c960ab7670, count: -9 ddb> machine ddbcpu 1 No such command ddb> trace db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:437 panic(ffffffff82550c9e) at panic+0x161 sys/kern/subr_prf.c:198 tcp_output(ffff800000e47598) at tcp_output+0x2a72 sys/netinet/tcp_output.c:727 tcp_send(fffffd8077106668,fffffd8064ec8900,0,fffffd8064ec8f00) at tcp_send+0xc4 sys/netinet/tcp_usrreq.c:944 sosend(fffffd8077106668,0,ffff80002b4e1140,0,fffffd8064ec8f00,0) at sosend+0x62a pru_send sys/sys/protosw.h:331 [inline] sosend(fffffd8077106668,0,ffff80002b4e1140,0,fffffd8064ec8f00,0) at sosend+0x62a sys/kern/uipc_socket.c:646 sendit(ffff8000216f0540,9,ffff80002b4e12c0,0,ffff80002b4e13c0) at sendit+0x64d sys/kern/uipc_syscalls.c:694 sys_sendmsg(ffff8000216f0540,ffff80002b4e1368,ffff80002b4e13c0) at sys_sendmsg+0x198 sys/kern/uipc_syscalls.c:601 syscall(ffff80002b4e1430) at syscall+0x447 sys/arch/amd64/amd64/trap.c:585 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x6c960ab7670, count: -9