panic: tcp_output Stopped at db_enter+0x18: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND 21225 31883 32767 0x10 0 1 syz-executor.2 *176441 31883 32767 0x10 0x4000000 0 syz-executor.2 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(ffff800000bcf200) at tcp_output+0x2cd2 sys/netinet/tcp_output.c:727 tcp_send(fffffd80675b4418,fffffd8072cee000,0,fffffd806be37e00) at tcp_send+0xc4 sys/netinet/tcp_usrreq.c:953 sosend(fffffd80675b4418,0,ffff80002e4b2f60,0,fffffd806be37e00,0) at sosend+0x62a pru_send sys/sys/protosw.h:331 [inline] sosend(fffffd80675b4418,0,ffff80002e4b2f60,0,fffffd806be37e00,0) at sosend+0x62a sys/kern/uipc_socket.c:646 sendit(ffff80002ca797a0,4,ffff80002e4b30e0,0,ffff80002e4b31d0) at sendit+0x65d sys/kern/uipc_syscalls.c:694 sys_sendmsg(ffff80002ca797a0,ffff80002e4b3188,ffff80002e4b31d0) at sys_sendmsg+0x198 sys/kern/uipc_syscalls.c:601 syscall(ffff80002e4b3250) at syscall+0x4c3 mi_syscall sys/sys/syscall_mi.h:101 [inline] syscall(ffff80002e4b3250) at syscall+0x4c3 sys/arch/amd64/amd64/trap.c:585 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x36c44dd48b0, 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(ffff800000bcf200) at tcp_output+0x2cd2 sys/netinet/tcp_output.c:727 tcp_send(fffffd80675b4418,fffffd8072cee000,0,fffffd806be37e00) at tcp_send+0xc4 sys/netinet/tcp_usrreq.c:953 sosend(fffffd80675b4418,0,ffff80002e4b2f60,0,fffffd806be37e00,0) at sosend+0x62a pru_send sys/sys/protosw.h:331 [inline] sosend(fffffd80675b4418,0,ffff80002e4b2f60,0,fffffd806be37e00,0) at sosend+0x62a sys/kern/uipc_socket.c:646 sendit(ffff80002ca797a0,4,ffff80002e4b30e0,0,ffff80002e4b31d0) at sendit+0x65d sys/kern/uipc_syscalls.c:694 sys_sendmsg(ffff80002ca797a0,ffff80002e4b3188,ffff80002e4b31d0) at sys_sendmsg+0x198 sys/kern/uipc_syscalls.c:601 syscall(ffff80002e4b3250) at syscall+0x4c3 mi_syscall sys/sys/syscall_mi.h:101 [inline] syscall(ffff80002e4b3250) at syscall+0x4c3 sys/arch/amd64/amd64/trap.c:585 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x36c44dd48b0, count: -9 ddb{0}> show registers rdi 0 rsi 0x1 rbp 0xffff80002e4b2bc0 rbx 0xffffffff829a1b8f cpu_info_full_primary+0x2b8f rdx 0xffff800000bdb5c0 rcx 0 rax 0xffff80002ca797a0 r8 0x101010101010101 r9 0x8080808080808080 r10 0xed16c8986910a022 r11 0x28ca075e4dd8208a r12 0xffffffff829a1990 cpu_info_full_primary+0x2990 r13 0 r14 0 r15 0x1 rip 0xffffffff81a16d08 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff80002e4b2bb0 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{0}> show proc PROC (syz-executor.2) pid=176441 stat=onproc flags process=10 proc=4000000 pri=32, usrpri=76, nice=20 forw=0xffffffffffffffff, list=0xffff8000212f1268,0xffff80002ca78010 process=0xffff800022337620 user=0xffff80002e4ae000, vmspace=0xfffffd8067d8d018 estcpu=26, cpticks=1, pctcpu=0.0 user=0, sys=1, intr=0 ddb{0}> ps PID TID PPID UID S FLAGS WAIT COMMAND 37350 380292 81395 32767 2 0x10 syz-executor.5 24618 475757 56408 32767 2 0x10 syz-executor.0 24618 275281 56408 32767 2 0x4000010 syz-executor.0 79733 376582 76037 32767 2 0x10 syz-executor.4 79733 405370 76037 32767 3 0x4000090 fsleep syz-executor.4 31883 21225 82835 32767 7 0x10 syz-executor.2 *31883 176441 82835 32767 7 0x4000010 syz-executor.2 56375 338164 92032 32767 2 0x10 syz-executor.1 56375 6275 92032 32767 3 0x4000090 msgwait syz-executor.1 56375 377537 92032 32767 3 0x4000090 fsleep syz-executor.1 80729 114550 0 0 3 0x14200 bored sosplice 1710 465655 38768 32767 2 0x10 syz-executor.7 38768 298128 20677 0 3 0x82 wait syz-executor.7 76037 6637 94891 32767 3 0x90 nanoslp syz-executor.4 81395 348047 81968 32767 3 0x90 nanoslp syz-executor.5 12769 477532 89724 32767 2 0x10 syz-executor.6 89724 129857 20677 0 3 0x82 wait syz-executor.6 81968 95260 20677 0 3 0x82 wait syz-executor.5 94891 482002 20677 0 3 0x82 wait syz-executor.4 2243 17026 9459 32767 2 0x10 syz-executor.3 82835 343670 87486 32767 3 0x90 nanoslp syz-executor.2 92032 199154 74839 32767 2 0x10 syz-executor.1 9459 140083 20677 0 3 0x82 wait syz-executor.3 56408 45911 97474 32767 3 0x90 nanoslp syz-executor.0 74839 202108 20677 0 3 0x82 wait syz-executor.1 87486 167414 20677 0 3 0x82 wait syz-executor.2 97474 110717 20677 0 3 0x82 wait syz-executor.0 20677 146818 5614 0 3 0x82 wait syz-fuzzer 20677 328143 5614 0 3 0x4000082 thrsleep syz-fuzzer 20677 432599 5614 0 3 0x4000082 kqread syz-fuzzer 20677 95607 5614 0 3 0x4000082 thrsleep syz-fuzzer 20677 311244 5614 0 3 0x4000082 wait syz-fuzzer 20677 290094 5614 0 3 0x4000082 wait syz-fuzzer 20677 93626 5614 0 3 0x4000082 thrsleep syz-fuzzer 20677 460903 5614 0 3 0x4000082 thrsleep syz-fuzzer 20677 448640 5614 0 3 0x4000082 wait syz-fuzzer 20677 58843 5614 0 3 0x4000082 wait syz-fuzzer 20677 349149 5614 0 3 0x4000082 wait syz-fuzzer 20677 446227 5614 0 3 0x4000082 wait syz-fuzzer 20677 501201 5614 0 3 0x4000082 thrsleep syz-fuzzer 20677 350043 5614 0 3 0x4000082 thrsleep syz-fuzzer 20677 361880 5614 0 3 0x4000082 wait syz-fuzzer 20677 39458 5614 0 3 0x4000082 thrsleep syz-fuzzer 5614 104300 3531 0 3 0x10008a sigsusp ksh 3531 505395 22719 0 3 0x9a kqread sshd 56102 160278 1 0 3 0x100083 ttyin getty 22719 181572 1 0 3 0x88 kqread sshd 95681 511732 68225 73 3 0x1100090 kqread syslogd 68225 518969 1 0 3 0x100082 netio syslogd 72277 320721 1 0 3 0x100080 kqread resolvd 42625 467195 34710 77 3 0x100092 kqread dhcpleased 75771 408955 34710 77 3 0x100092 kqread dhcpleased 34710 509237 1 0 3 0x80 kqread dhcpleased 52836 66997 0 0 3 0x14200 bored smr 54349 385809 0 0 2 0x14200 zerothread 27067 383374 0 0 3 0x14200 aiodoned aiodoned 59509 419724 0 0 3 0x14200 syncer update 89876 248359 0 0 3 0x14200 cleaner cleaner 27176 422146 0 0 3 0x14200 reaper reaper 38634 66664 0 0 3 0x14200 pgdaemon pagedaemon 61692 249078 0 0 3 0x14200 bored viomb 72211 467746 0 0 3 0x40014200 acpi0 acpi0 5416 90985 0 0 3 0x40014200 idle1 79344 53279 0 0 3 0x14200 bored softnet 52405 282989 0 0 3 0x14200 bored softnet 69429 109788 0 0 3 0x14200 bored softnet 70405 165568 0 0 3 0x14200 bored softnet 27044 323600 0 0 3 0x14200 bored systqmp 37951 320912 0 0 3 0x14200 bored systq 99417 264739 0 0 3 0x40014200 bored softclock 88863 110302 0 0 3 0x40014200 idle0 1 481900 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb{0}> show all locks Process 31883 (syz-executor.2) thread 0xffff80002ca797a0 (176441) 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 ddb{0}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim devbuf 10180 6408K 6419K 78643K 11270 0 pcb 13 8K 8K 78643K 13 0 rtable 234 6K 6K 78643K 358 0 ifaddr 82 16K 16K 78643K 84 0 sysctl 2 0K 0K 78643K 2 0 counters 56 35K 35K 78643K 56 0 ioctlops 0 0K 2K 78643K 33 0 iov 0 0K 16K 78643K 11 0 mount 1 1K 1K 78643K 1 0 log 0 0K 0K 78643K 4 0 vnodes 1270 79K 79K 78643K 1327 0 UFS quota 1 32K 32K 78643K 1 0 UFS mount 5 36K 36K 78643K 5 0 shm 2 1K 5K 78643K 16 0 VM map 2 1K 1K 78643K 2 0 sem 8 0K 0K 78643K 8 0 dirhash 12 2K 2K 78643K 12 0 ACPI 1697 195K 286K 78643K 12548 0 file desc 23 85K 121K 78643K 426 0 proc 56 78K 115K 78643K 484 0 subproc 104 6K 6K 78643K 104 0 NFS srvsock 1 0K 0K 78643K 1 0 NFS daemon 1 16K 16K 78643K 1 0 ip_moptions 0 0K 0K 78643K 9 0 in_multi 99 6K 6K 78643K 99 0 ether_multi 1 0K 0K 78643K 1 0 ISOFS mount 1 32K 32K 78643K 1 0 MSDOSFS mount 1 16K 16K 78643K 1 0 ttys 61 281K 281K 78643K 61 0 exec 0 0K 2K 78643K 676 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 241 82K 83K 78643K 3958 0 UVM aobj 24 6K 6K 78643K 30 0 memdesc 1 4K 4K 78643K 1 0 crypto data 1 1K 1K 78643K 1 0 ip6_options 0 0K 0K 78643K 10 0 NDP 11 0K 2K 78643K 27 0 temp 107 4721K 4785K 78643K 3970 0 kqueue 12 18K 24K 78643K 38 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 92 0 89 2 1 1 2 0 8 0 rtentry 112 111 0 1 4 0 4 4 0 8 0 unpcb 144 456 0 443 6 4 2 6 0 8 1 syncache 296 12 0 12 2 1 1 1 0 8 1 tcpqe 32 3 0 3 1 0 1 1 0 8 1 tcpcb 768 143 0 133 8 3 5 8 0 8 3 arp 120 18 0 0 1 0 1 1 0 8 0 inpcb 368 291 0 278 9 1 8 8 0 8 6 nd6 48 24 0 0 1 0 1 1 0 8 0 kcovpl 48 8 0 0 1 0 1 1 0 8 0 art_heap8 4096 1 0 0 1 0 1 1 0 8 0 art_heap4 256 452 0 0 29 0 29 29 0 8 0 art_table 32 453 0 0 4 0 4 4 0 8 0 art_node 16 110 0 10 1 0 1 1 0 8 0 sysvmsgpl 40 12 0 4 1 0 1 1 0 8 0 semupl 112 3 0 3 1 1 0 1 0 8 0 semapl 112 6 0 0 1 0 1 1 0 8 0 shmpl 112 27 0 6 1 0 1 1 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino2pl 256 1855 0 427 90 0 90 90 0 8 0 ffsino 272 1855 0 427 96 0 96 96 0 8 0 nchpl 144 2675 0 998 63 0 63 63 0 8 0 uvmvnodes 80 1968 0 0 41 0 41 41 0 8 0 vnodes 216 1968 0 0 110 0 110 110 0 8 0 namei 1024 9336 0 9336 2 1 1 2 0 8 1 percpumem 16 40 0 0 1 0 1 1 0 8 0 kstatmem 264 22 0 0 2 0 2 2 0 8 0 scxspl 216 7406 0 7406 9 1 8 8 0 8 8 plimitpl 152 53 0 31 2 1 1 2 0 8 0 sigapl 424 702 0 647 7 0 7 7 0 8 0 futexpl 64 3307 0 3305 1 0 1 1 0 8 0 knotepl 120 159 0 0 5 0 5 5 0 8 0 kqueuepl 216 145 0 136 5 1 4 5 0 8 3 pipepl 320 140 0 111 3 0 3 3 0 8 0 fdescpl 496 684 0 650 7 2 5 6 0 8 0 filepl 152 4619 0 4380 15 1 14 15 0 8 2 lockfpl 104 17 0 15 1 0 1 1 0 8 0 lockfspl 48 9 0 7 1 0 1 1 0 8 0 sessionpl 144 23 0 7 1 0 1 1 0 8 0 pgrppl 48 23 0 7 1 0 1 1 0 8 0 ucredpl 104 376 0 358 1 0 1 1 0 8 0 zombiepl 144 650 0 647 1 0 1 1 0 8 0 processpl 1064 702 0 647 5 1 4 5 0 8 0 procpl 672 1366 0 1291 10 2 8 10 0 8 0 sosppl 168 10 0 10 1 0 1 1 0 8 1 sockpl 488 842 0 813 32 20 12 21 0 8 7 mcl64k 65536 13 0 0 2 0 2 2 0 8 0 mcl16k 16384 6 0 0 1 0 1 1 0 8 0 mcl12k 12288 11 0 0 2 0 2 2 0 8 0 mcl9k 9216 4 0 0 1 0 1 1 0 8 0 mcl8k 8192 9 0 0 2 0 2 2 0 8 0 mcl4k 4096 7 0 0 1 0 1 1 0 8 0 mcl2k2 2112 1 0 0 1 0 1 1 0 8 0 mcl2k 2048 340 0 0 43 0 43 43 0 8 0 mtagpl 96 2 0 0 1 0 1 1 0 8 0 mbufpl 256 383 0 0 24 0 24 24 0 8 0 bufpl 288 3863 0 128 267 0 267 267 0 8 0 anonpl 24 137695 0 125415 113 3 110 110 0 186 23 amapchunkpl 152 9885 0 9272 32 2 30 30 0 158 2 amappl16 200 2520 0 2149 40 11 29 33 0 8 8 amappl15 192 211 0 202 1 0 1 1 0 8 0 amappl14 184 144 0 134 1 0 1 1 0 8 0 amappl13 176 80 0 78 1 0 1 1 0 8 0 amappl12 168 10 0 6 1 0 1 1 0 8 0 amappl11 160 81 0 65 1 0 1 1 0 8 0 amappl10 152 47 0 44 1 0 1 1 0 8 0 amappl9 144 532 0 527 1 0 1 1 0 8 0 amappl8 136 593 0 533 3 0 3 3 0 8 0 amappl7 128 167 0 147 1 0 1 1 0 8 0 amappl6 120 226 0 214 2 1 1 2 0 8 0 amappl5 112 383 0 361 1 0 1 1 0 8 0 amappl4 104 845 0 818 2 1 1 2 0 8 0 amappl3 96 1474 0 1420 2 0 2 2 0 8 0 amappl2 88 415 0 384 2 0 2 2 0 8 0 amappl1 80 18529 0 17825 20 3 17 20 0 8 0 amappl 88 3508 0 3348 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 29 0 6 1 0 1 1 0 8 0 uaddrrnd 24 684 0 650 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 684 0 650 1 0 1 1 0 8 0 vmmpekpl 168 9997 0 9944 3 0 3 3 0 8 0 vmmpepl 168 69912 0 67323 139 2 137 138 0 357 19 vmsppl 368 683 0 650 4 0 4 4 0 8 0 rwobjpl 56 21117 0 17793 52 1 51 51 0 8 0 pdppl 4096 1375 0 1300 109 28 81 93 0 8 6 pvpl 32 357980 0 340792 256 12 244 256 0 265 87 pmappl 248 683 0 650 4 1 3 3 0 8 0 extentpl 40 56 0 38 1 0 1 1 0 8 0 phpool 112 686 0 32 19 0 19 19 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(ffff800000bcf200) at tcp_output+0x2cd2 sys/netinet/tcp_output.c:727 tcp_send(fffffd80675b4418,fffffd8072cee000,0,fffffd806be37e00) at tcp_send+0xc4 sys/netinet/tcp_usrreq.c:953 sosend(fffffd80675b4418,0,ffff80002e4b2f60,0,fffffd806be37e00,0) at sosend+0x62a pru_send sys/sys/protosw.h:331 [inline] sosend(fffffd80675b4418,0,ffff80002e4b2f60,0,fffffd806be37e00,0) at sosend+0x62a sys/kern/uipc_socket.c:646 sendit(ffff80002ca797a0,4,ffff80002e4b30e0,0,ffff80002e4b31d0) at sendit+0x65d sys/kern/uipc_syscalls.c:694 sys_sendmsg(ffff80002ca797a0,ffff80002e4b3188,ffff80002e4b31d0) at sys_sendmsg+0x198 sys/kern/uipc_syscalls.c:601 syscall(ffff80002e4b3250) at syscall+0x4c3 mi_syscall sys/sys/syscall_mi.h:101 [inline] syscall(ffff80002e4b3250) at syscall+0x4c3 sys/arch/amd64/amd64/trap.c:585 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x36c44dd48b0, count: -9 ddb{0}> machine ddbcpu 1 Stopped at x86_ipi_db+0x1a: addq $0x8,%rsp x86_ipi_db(ffff800020dd8ff0) at x86_ipi_db+0x1a sys/arch/amd64/amd64/db_interface.c:393 x86_ipi_handler() at x86_ipi_handler+0xb7 sys/arch/amd64/amd64/ipi.c:106 Xresume_lapic_ipi() at Xresume_lapic_ipi+0x23 end of kernel end trace frame: 0x7f7ffffda030, count: 12 ddb{1}> trace x86_ipi_db(ffff800020dd8ff0) at x86_ipi_db+0x1a sys/arch/amd64/amd64/db_interface.c:393 x86_ipi_handler() at x86_ipi_handler+0xb7 sys/arch/amd64/amd64/ipi.c:106 Xresume_lapic_ipi() at Xresume_lapic_ipi+0x23 end of kernel end trace frame: 0x7f7ffffda030, count: -3