panic: tcp_output Stopped at db_enter+0x18: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND * 57003 87353 32767 0x10 0x4000000 0 syz-executor.6 393604 93629 32767 0x10 0 1 syz-executor.1 db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:437 panic(ffffffff8257b2ef) at panic+0x177 sys/kern/subr_prf.c:198 tcp_output(ffff800000bba000) at tcp_output+0x2cd2 sys/netinet/tcp_output.c:727 tcp_send(fffffd8065d91ba8,fffffd8077c89a00,0,fffffd807ea65300) at tcp_send+0xc4 sys/netinet/tcp_usrreq.c:953 sosend(fffffd8065d91ba8,0,ffff80002e504600,0,fffffd807ea65300,0) at sosend+0x62a pru_send sys/sys/protosw.h:331 [inline] sosend(fffffd8065d91ba8,0,ffff80002e504600,0,fffffd807ea65300,0) at sosend+0x62a sys/kern/uipc_socket.c:646 sendit(ffff800027c19500,3,ffff80002e504780,0,ffff80002e504870) at sendit+0x65d sys/kern/uipc_syscalls.c:694 sys_sendmsg(ffff800027c19500,ffff80002e504828,ffff80002e504870) at sys_sendmsg+0x198 sys/kern/uipc_syscalls.c:601 syscall(ffff80002e5048f0) at syscall+0x4c3 mi_syscall sys/sys/syscall_mi.h:101 [inline] syscall(ffff80002e5048f0) at syscall+0x4c3 sys/arch/amd64/amd64/trap.c:585 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x606ea5505e0, 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{0}> ddb{0}> set $lines = 0 ddb{0}> set $maxwidth = 0 ddb{0}> show panic *cpu0: tcp_output ddb{0}> trace db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:437 panic(ffffffff8257b2ef) at panic+0x177 sys/kern/subr_prf.c:198 tcp_output(ffff800000bba000) at tcp_output+0x2cd2 sys/netinet/tcp_output.c:727 tcp_send(fffffd8065d91ba8,fffffd8077c89a00,0,fffffd807ea65300) at tcp_send+0xc4 sys/netinet/tcp_usrreq.c:953 sosend(fffffd8065d91ba8,0,ffff80002e504600,0,fffffd807ea65300,0) at sosend+0x62a pru_send sys/sys/protosw.h:331 [inline] sosend(fffffd8065d91ba8,0,ffff80002e504600,0,fffffd807ea65300,0) at sosend+0x62a sys/kern/uipc_socket.c:646 sendit(ffff800027c19500,3,ffff80002e504780,0,ffff80002e504870) at sendit+0x65d sys/kern/uipc_syscalls.c:694 sys_sendmsg(ffff800027c19500,ffff80002e504828,ffff80002e504870) at sys_sendmsg+0x198 sys/kern/uipc_syscalls.c:601 syscall(ffff80002e5048f0) at syscall+0x4c3 mi_syscall sys/sys/syscall_mi.h:101 [inline] syscall(ffff80002e5048f0) at syscall+0x4c3 sys/arch/amd64/amd64/trap.c:585 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x606ea5505e0, count: -9 ddb{0}> show registers rdi 0 rsi 0x1 rbp 0xffff80002e504260 rbx 0xffffffff829a1b8f cpu_info_full_primary+0x2b8f rdx 0xffff800000bee6c0 rcx 0 rax 0xffff800027c19500 r8 0x101010101010101 r9 0x8080808080808080 r10 0x96936f434ad60c7d r11 0xe6e8a753255b82fd r12 0xffffffff829a1990 cpu_info_full_primary+0x2990 r13 0 r14 0 r15 0x1 rip 0xffffffff81a16d08 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff80002e504250 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{0}> show proc PROC (syz-executor.6) pid=57003 stat=onproc flags process=10 proc=4000000 pri=32, usrpri=78, nice=20 forw=0xffffffffffffffff, list=0xffff800027c18000,0xffff800027c18550 process=0xffff8000ffff0440 user=0xffff80002e4ff000, vmspace=0xfffffd8065af5a28 estcpu=36, cpticks=1, pctcpu=0.0 user=0, sys=1, intr=0 ddb{0}> ps PID TID PPID UID S FLAGS WAIT COMMAND 22802 121187 70139 32767 2 0x10 syz-executor.3 22802 18133 70139 32767 3 0x4000090 ttyout syz-executor.3 58153 365073 96142 32767 2 0x490 syz-executor.4 58153 120413 96142 32767 3 0x4000090 fsleep syz-executor.4 58153 379532 96142 32767 3 0x4000090 fsleep syz-executor.4 68223 167519 95961 32767 2 0x10 syz-executor.5 68223 485844 95961 32767 3 0x4000090 fsleep syz-executor.5 17535 303452 93629 32767 2 0x10 syz-executor.1 17535 433251 93629 32767 3 0x4000090 fsleep syz-executor.1 87353 221963 56372 32767 2 0x10 syz-executor.6 *87353 57003 56372 32767 7 0x4000010 syz-executor.6 63368 163839 81807 32767 2 0x490 syz-executor.2 63368 410343 81807 32767 2 0x4000010 syz-executor.2 63368 286780 81807 32767 3 0x4000090 fsleep syz-executor.2 63368 218763 81807 32767 3 0x4000090 fsleep syz-executor.2 63368 287929 81807 32767 2 0x4000010 syz-executor.2 81807 391810 4327 32767 3 0x90 nanoslp syz-executor.2 4327 11730 13122 0 3 0x82 wait syz-executor.2 96142 161678 85042 32767 2 0x490 syz-executor.4 85042 40770 13122 0 3 0x82 wait syz-executor.4 56372 116759 60034 32767 3 0x90 nanoslp syz-executor.6 60034 234016 13122 0 3 0x82 wait syz-executor.6 9274 177555 0 0 3 0x14200 bored sosplice 88011 391450 85069 32767 2 0x490 syz-executor.7 85069 160755 13122 0 3 0x82 wait syz-executor.7 95961 322357 33171 32767 2 0x10 syz-executor.5 33171 73965 13122 0 3 0x82 wait syz-executor.5 70139 240749 65018 32767 3 0x90 nanoslp syz-executor.3 65018 368322 13122 0 3 0x82 wait syz-executor.3 93629 393604 14855 32767 7 0x10 syz-executor.1 50196 212374 87956 32767 2 0x10 syz-executor.0 14855 253950 13122 0 3 0x82 wait syz-executor.1 87956 8523 13122 0 3 0x82 wait syz-executor.0 13122 250171 53549 0 3 0x82 wait syz-fuzzer 13122 501498 53549 0 3 0x4000082 thrsleep syz-fuzzer 13122 101178 53549 0 3 0x4000082 thrsleep syz-fuzzer 13122 379504 53549 0 3 0x4000082 wait syz-fuzzer 13122 132118 53549 0 3 0x4000082 thrsleep syz-fuzzer 13122 512228 53549 0 3 0x4000082 thrsleep syz-fuzzer 13122 315058 53549 0 3 0x4000082 wait syz-fuzzer 13122 359128 53549 0 3 0x4000082 thrsleep syz-fuzzer 13122 169258 53549 0 3 0x4000082 wait syz-fuzzer 13122 427618 53549 0 3 0x4000082 thrsleep syz-fuzzer 13122 63346 53549 0 3 0x4000082 wait syz-fuzzer 13122 330450 53549 0 3 0x4000082 wait syz-fuzzer 13122 304449 53549 0 3 0x4000082 wait syz-fuzzer 13122 397174 53549 0 3 0x4000082 thrsleep syz-fuzzer 13122 238790 53549 0 3 0x4000082 kqread syz-fuzzer 13122 71446 53549 0 3 0x4000082 wait syz-fuzzer 53549 290162 67727 0 3 0x10008a sigsusp ksh 67727 317866 82641 0 3 0x9a kqread sshd 47135 293343 1 0 3 0x100083 ttyin getty 82641 159416 1 0 3 0x88 kqread sshd 25064 214327 38832 73 2 0x1100010 syslogd 38832 44346 1 0 3 0x100082 netio syslogd 30130 408163 1 0 3 0x100080 kqread resolvd 80336 475665 14127 77 3 0x100092 kqread dhcpleased 70817 275140 14127 77 3 0x100092 kqread dhcpleased 14127 165707 1 0 3 0x80 kqread dhcpleased 21998 315668 0 0 3 0x14200 bored smr 28799 379641 0 0 2 0x14200 zerothread 58091 148685 0 0 3 0x14200 aiodoned aiodoned 43674 164000 0 0 3 0x14200 syncer update 97474 75109 0 0 3 0x14200 cleaner cleaner 1896 154309 0 0 3 0x14200 reaper reaper 62056 361187 0 0 3 0x14200 pgdaemon pagedaemon 79980 476775 0 0 3 0x14200 bored viomb 24595 388932 0 0 3 0x40014200 acpi0 acpi0 35851 103877 0 0 3 0x40014200 idle1 54153 206276 0 0 3 0x14200 bored softnet 38225 425535 0 0 3 0x14200 bored softnet 15527 480494 0 0 3 0x14200 bored softnet 31750 306789 0 0 3 0x14200 bored softnet 85266 126561 0 0 3 0x14200 bored systqmp 51202 294957 0 0 3 0x14200 bored systq 90476 94553 0 0 2 0x40014200 softclock 38932 394505 0 0 3 0x40014200 idle0 1 508947 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb{0}> show all locks Process 87353 (syz-executor.6) thread 0xffff800027c19500 (57003) exclusive rwlock netlock r = 0 (0xffffffff8291ebe0) #0 witness_lock+0x44d #1 sosend+0x500 sys/kern/uipc_socket.c:632 #2 sendit+0x65d sys/kern/uipc_syscalls.c:694 #3 sys_sendmsg+0x198 sys/kern/uipc_syscalls.c:601 #4 syscall+0x4c3 mi_syscall sys/sys/syscall_mi.h:101 [inline] #4 syscall+0x4c3 sys/arch/amd64/amd64/trap.c:585 #5 Xsyscall+0x128 Process 25064 (syslogd) thread 0xffff8000ffff7cf0 (214327) exclusive rrwlock inode r = 0 (0xfffffd806ebf1e68) #0 witness_lock+0x44d #1 rw_enter+0x3e1 sys/kern/kern_rwlock.c:310 #2 rrw_enter+0x8b sys/kern/kern_rwlock.c:465 #3 VOP_LOCK+0x87 sys/kern/vfs_vops.c:518 #4 vn_lock+0x84 sys/kern/vfs_vnops.c:564 #5 sys_fsync+0xf5 sys/kern/vfs_syscalls.c:2935 #6 syscall+0x435 mi_syscall sys/sys/syscall_mi.h:101 [inline] #6 syscall+0x435 sys/arch/amd64/amd64/trap.c:585 #7 Xsyscall+0x128 ddb{0}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim devbuf 10199 6410K 6419K 78643K 11323 0 pcb 13 16K 20K 78643K 19 0 rtable 252 7K 7K 78643K 1475 0 ifaddr 82 17K 17K 78643K 163 0 sysctl 3 1K 1K 78643K 3 0 counters 56 35K 35K 78643K 78 0 ioctlops 0 0K 2K 78643K 142 0 iov 0 0K 24K 78643K 2112 0 mount 1 1K 1K 78643K 1 0 log 0 0K 0K 78643K 4 0 vnodes 1271 79K 79K 78643K 3176 0 UFS quota 1 32K 32K 78643K 1 0 UFS mount 5 36K 36K 78643K 5 0 shm 2 1K 9K 78643K 132 0 VM map 2 1K 1K 78643K 2 0 sem 12 0K 0K 78643K 2982 0 dirhash 12 2K 2K 78643K 12 0 ACPI 1697 195K 286K 78643K 12548 0 file desc 24 89K 117K 78643K 11092 0 sigio 0 0K 0K 78643K 486 0 proc 56 78K 103K 78643K 1522 0 subproc 104 6K 6K 78643K 247 0 NFS srvsock 1 0K 0K 78643K 1 0 NFS daemon 1 16K 16K 78643K 1 0 ip_moptions 0 0K 0K 78643K 898 0 in_multi 99 6K 6K 78643K 339 0 ether_multi 1 0K 0K 78643K 29 0 mrt 2 0K 0K 78643K 2 0 ISOFS mount 1 32K 32K 78643K 1 0 MSDOSFS mount 1 16K 16K 78643K 1 0 ttys 175 784K 784K 78643K 175 0 exec 0 0K 2K 78643K 2076 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 321 88K 104K 78643K 69264 0 UVM aobj 131 8K 8K 78643K 136 0 memdesc 1 4K 4K 78643K 1 0 crypto data 1 1K 1K 78643K 1 0 ip6_options 0 0K 0K 78643K 336 0 NDP 11 0K 2K 78643K 60 0 temp 124 4726K 4810K 78643K 30117 0 kqueue 13 20K 28K 78643K 1235 0 SYN cache 2 16K 16K 78643K 2 0 ddb{0}> show all pools Name Size Requests Fail Releases Pgreq Pgrel Npage Hiwat Minpg Maxpg Idle plcache 128 22 0 0 1 0 1 1 0 8 0 rtpcb 120 1131 0 1128 17 16 1 3 0 8 0 rtentry 112 254 0 135 4 0 4 4 0 8 0 unpcb 144 10690 0 10677 72 71 1 7 0 8 0 syncache 296 101 0 101 23 23 0 1 0 8 0 sackhl 24 1 0 1 1 1 0 1 0 8 0 tcpqe 32 47 0 47 18 18 0 1 0 8 0 tcpcb 768 4590 0 4585 179 175 4 17 0 8 3 arp 120 44 0 24 1 0 1 1 0 8 0 ipq 40 21 0 21 7 7 0 1 0 8 0 ipqe 40 75 0 75 7 7 0 1 0 8 0 inpcb 368 20010 0 19997 224 222 2 20 0 8 0 nd6 48 75 0 44 1 0 1 1 0 8 0 kcovpl 48 19 0 11 1 0 1 1 0 8 0 art_heap8 4096 1 0 0 1 0 1 1 0 8 0 art_heap4 256 994 0 519 31 1 30 30 0 8 0 art_table 32 995 0 519 4 0 4 4 0 8 0 art_node 16 253 0 144 1 0 1 1 0 8 0 sysvmsgpl 40 28 0 20 1 0 1 1 0 8 0 semapl 112 2980 0 2970 1 0 1 1 0 8 0 shmpl 112 133 0 5 4 0 4 4 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino2pl 256 16031 0 14569 92 0 92 92 0 8 0 ffsino 272 16031 0 14569 98 0 98 98 0 8 0 nchpl 144 30795 0 29154 63 0 63 63 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 103649 0 103649 5 4 1 2 0 8 1 percpumem 16 51 0 11 1 0 1 1 0 8 0 kstatmem 264 44 0 22 2 0 2 2 0 8 0 scxspl 216 96287 0 96287 31 30 1 8 0 8 1 plimitpl 152 2751 0 2728 18 17 1 2 0 8 0 sigapl 424 11357 0 11302 7 0 7 7 0 8 0 futexpl 64 103077 0 103071 6 5 1 1 0 8 0 knotepl 120 896 0 0 17 0 17 17 0 8 0 kqueuepl 216 3590 0 3581 73 68 5 7 0 8 4 pipepl 320 2730 0 2702 74 71 3 8 0 8 0 fdescpl 496 11339 0 11304 7 2 5 6 0 8 0 filepl 152 84115 0 83877 130 118 12 24 0 8 2 lockfpl 104 1640 0 1638 1 0 1 1 0 8 0 lockfspl 48 470 0 468 1 0 1 1 0 8 0 sessionpl 144 34 0 18 1 0 1 1 0 8 0 pgrppl 48 141 0 125 1 0 1 1 0 8 0 ucredpl 104 12574 0 12556 1 0 1 1 0 8 0 zombiepl 144 11304 0 11302 1 0 1 1 0 8 0 processpl 1064 11357 0 11302 4 0 4 4 0 8 0 procpl 672 33981 0 33901 21 13 8 8 0 8 1 sosppl 168 204 0 204 15 15 0 1 0 8 0 sockpl 488 32020 0 31994 544 536 8 37 0 8 4 mcl64k 65536 28 0 0 3 0 3 3 0 8 0 mcl16k 16384 25 0 0 4 1 3 3 0 8 0 mcl12k 12288 31 0 0 2 0 2 2 0 8 0 mcl9k 9216 25 0 0 2 0 2 2 0 8 0 mcl8k 8192 42 0 0 6 2 4 6 0 8 0 mcl4k 4096 50 0 0 4 0 4 4 0 8 0 mcl2k2 2112 8 0 0 1 0 1 1 0 8 0 mcl2k 2048 464 0 0 43 22 21 43 0 8 0 mtagpl 96 4 0 0 1 0 1 1 0 8 0 mbufpl 256 1922 0 0 99 0 99 99 0 8 0 bufpl 288 21854 0 15527 453 0 453 453 0 8 0 anonpl 24 2343312 0 2330553 277 168 109 124 0 186 3 amapchunkpl 152 205299 0 204659 132 95 37 40 0 158 8 amappl16 200 35857 0 35455 170 147 23 42 0 8 0 amappl15 192 2814 0 2806 1 0 1 1 0 8 0 amappl14 184 2772 0 2767 1 0 1 1 0 8 0 amappl13 176 157 0 156 1 0 1 1 0 8 0 amappl12 168 2754 0 2746 1 0 1 1 0 8 0 amappl11 160 1941 0 1920 1 0 1 1 0 8 0 amappl10 152 751 0 744 1 0 1 1 0 8 0 amappl9 144 2414 0 2410 1 0 1 1 0 8 0 amappl8 136 2055 0 1937 5 0 5 5 0 8 0 amappl7 128 1199 0 1180 1 0 1 1 0 8 0 amappl6 120 2202 0 2185 2 1 1 2 0 8 0 amappl5 112 6502 0 6487 1 0 1 1 0 8 0 amappl4 104 6323 0 6282 2 0 2 2 0 8 0 amappl3 96 37710 0 37643 4 2 2 3 0 8 0 amappl2 88 3280 0 3234 5 3 2 2 0 8 0 amappl1 80 287156 0 286408 20 3 17 19 0 8 0 amappl 88 68124 0 67938 5 0 5 5 0 92 0 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 72 135 0 5 3 0 3 3 0 8 0 uaddrrnd 24 11340 0 11305 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 11340 0 11305 1 0 1 1 0 8 0 vmmpekpl 168 92505 0 92446 3 0 3 3 0 8 0 vmmpepl 168 1128455 0 1125608 278 145 133 147 0 357 0 vmsppl 368 11339 0 11305 4 0 4 4 0 8 0 rwobjpl 56 290568 0 283047 118 8 110 112 0 8 0 pdppl 4096 22687 0 22610 353 272 81 91 0 8 4 pvpl 32 4518122 0 4499659 590 375 215 255 0 265 42 pmappl 248 11339 0 11305 4 1 3 3 0 8 0 extentpl 40 56 0 38 1 0 1 1 0 8 0 phpool 112 1426 0 526 27 0 27 27 0 8 0 ddb{0}> machine ddbcpu 0 Invalid cpu 0 ddb{0}> trace db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:437 panic(ffffffff8257b2ef) at panic+0x177 sys/kern/subr_prf.c:198 tcp_output(ffff800000bba000) at tcp_output+0x2cd2 sys/netinet/tcp_output.c:727 tcp_send(fffffd8065d91ba8,fffffd8077c89a00,0,fffffd807ea65300) at tcp_send+0xc4 sys/netinet/tcp_usrreq.c:953 sosend(fffffd8065d91ba8,0,ffff80002e504600,0,fffffd807ea65300,0) at sosend+0x62a pru_send sys/sys/protosw.h:331 [inline] sosend(fffffd8065d91ba8,0,ffff80002e504600,0,fffffd807ea65300,0) at sosend+0x62a sys/kern/uipc_socket.c:646 sendit(ffff800027c19500,3,ffff80002e504780,0,ffff80002e504870) at sendit+0x65d sys/kern/uipc_syscalls.c:694 sys_sendmsg(ffff800027c19500,ffff80002e504828,ffff80002e504870) at sys_sendmsg+0x198 sys/kern/uipc_syscalls.c:601 syscall(ffff80002e5048f0) at syscall+0x4c3 mi_syscall sys/sys/syscall_mi.h:101 [inline] syscall(ffff80002e5048f0) at syscall+0x4c3 sys/arch/amd64/amd64/trap.c:585 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x606ea5505e0, count: -9 ddb{0}> machine ddbcpu 1