panic: tcp_output Stopped at db_enter+0x18: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND 17703 55207 32767 0x10 0 0 syz-executor.4 * 22811 55207 32767 0x10 0x4000000 1 syz-executor.4 db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:437 panic(ffffffff8257befc) at panic+0x177 sys/kern/subr_prf.c:198 tcp_output(ffff800000bb8000) at tcp_output+0x2cd2 sys/netinet/tcp_output.c:727 tcp_send(fffffd807df25ba8,fffffd807711da00,0,fffffd806e5c3300) at tcp_send+0xc4 sys/netinet/tcp_usrreq.c:953 sosend(fffffd807df25ba8,0,ffff800027bc0130,0,fffffd806e5c3300,0) at sosend+0x62a pru_send sys/sys/protosw.h:331 [inline] sosend(fffffd807df25ba8,0,ffff800027bc0130,0,fffffd806e5c3300,0) at sosend+0x62a sys/kern/uipc_socket.c:646 sendit(ffff8000fffef510,3,ffff800027bc02b0,0,ffff800027bc03a0) at sendit+0x65d sys/kern/uipc_syscalls.c:694 sys_sendmsg(ffff8000fffef510,ffff800027bc0358,ffff800027bc03a0) at sys_sendmsg+0x198 sys/kern/uipc_syscalls.c:601 syscall(ffff800027bc0420) at syscall+0x4c3 mi_syscall sys/sys/syscall_mi.h:101 [inline] syscall(ffff800027bc0420) at syscall+0x4c3 sys/arch/amd64/amd64/trap.c:585 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x9cdaac15d0, 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{1}> ddb{1}> set $lines = 0 ddb{1}> set $maxwidth = 0 ddb{1}> show panic *cpu1: tcp_output ddb{1}> trace db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:437 panic(ffffffff8257befc) at panic+0x177 sys/kern/subr_prf.c:198 tcp_output(ffff800000bb8000) at tcp_output+0x2cd2 sys/netinet/tcp_output.c:727 tcp_send(fffffd807df25ba8,fffffd807711da00,0,fffffd806e5c3300) at tcp_send+0xc4 sys/netinet/tcp_usrreq.c:953 sosend(fffffd807df25ba8,0,ffff800027bc0130,0,fffffd806e5c3300,0) at sosend+0x62a pru_send sys/sys/protosw.h:331 [inline] sosend(fffffd807df25ba8,0,ffff800027bc0130,0,fffffd806e5c3300,0) at sosend+0x62a sys/kern/uipc_socket.c:646 sendit(ffff8000fffef510,3,ffff800027bc02b0,0,ffff800027bc03a0) at sendit+0x65d sys/kern/uipc_syscalls.c:694 sys_sendmsg(ffff8000fffef510,ffff800027bc0358,ffff800027bc03a0) at sys_sendmsg+0x198 sys/kern/uipc_syscalls.c:601 syscall(ffff800027bc0420) at syscall+0x4c3 mi_syscall sys/sys/syscall_mi.h:101 [inline] syscall(ffff800027bc0420) at syscall+0x4c3 sys/arch/amd64/amd64/trap.c:585 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x9cdaac15d0, count: -9 ddb{1}> show registers rdi 0 rsi 0x1 rbp 0xffff800027bbfd90 rbx 0xffff800020dd9b8f rdx 0xffff800000be2c00 rcx 0 rax 0xffff8000fffef510 r8 0x101010101010101 r9 0x8080808080808080 r10 0x237d41f7ee7e841b r11 0xe48978ebd07e245f r12 0xffff800020dd9990 r13 0 r14 0 r15 0x1 rip 0xffffffff823fc058 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff800027bbfd80 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{1}> show proc PROC (syz-executor.4) pid=22811 stat=onproc flags process=10 proc=4000000 pri=32, usrpri=79, nice=20 forw=0xffffffffffffffff, list=0xffff8000fffeefd0,0xffff8000fffef7c0 process=0xffff80002129b618 user=0xffff800027bbb000, vmspace=0xfffffd8069803b98 estcpu=36, cpticks=1, pctcpu=0.0 user=0, sys=0, intr=0 ddb{1}> ps PID TID PPID UID S FLAGS WAIT COMMAND 48910 163997 9189 32767 2 0x10 syz-executor.2 68875 158610 53811 32767 2 0x10 syz-executor.0 44769 39081 48136 32767 2 0x10 syz-executor.7 55207 17703 83701 32767 7 0x10 syz-executor.4 *55207 22811 83701 32767 7 0x4000010 syz-executor.4 88112 38136 51060 32767 3 0x90 nanoslp syz-executor.6 88112 3052 51060 32767 3 0x4000090 fsleep syz-executor.6 63094 395095 42113 32767 2 0x10 syz-executor.5 41763 97910 5402 32767 2 0x10 syz-executor.3 41763 128886 5402 32767 3 0x4000090 fsleep syz-executor.3 89172 226018 8689 32767 2 0x10 syz-executor.1 89172 19651 8689 32767 3 0x4000090 pipewr syz-executor.1 89172 41733 8689 32767 3 0x4000090 fsleep syz-executor.1 68909 179695 0 0 3 0x14200 bored sosplice 51060 58108 78799 32767 3 0x90 nanoslp syz-executor.6 48136 402129 86666 32767 3 0x90 nanoslp syz-executor.7 78799 117206 84675 0 3 0x82 wait syz-executor.6 42113 250140 37762 32767 3 0x90 nanoslp syz-executor.5 86666 190434 84675 0 3 0x82 wait syz-executor.7 83701 78012 99577 32767 3 0x90 nanoslp syz-executor.4 37762 168481 84675 0 3 0x82 wait syz-executor.5 99577 184620 84675 0 3 0x82 wait syz-executor.4 5402 351887 40842 32767 3 0x90 nanoslp syz-executor.3 8689 81161 33476 32767 3 0x90 nanoslp syz-executor.1 9189 260089 84604 32767 2 0x10 syz-executor.2 40842 350545 84675 0 3 0x82 wait syz-executor.3 84604 36228 84675 0 3 0x82 wait syz-executor.2 33476 478810 84675 0 3 0x82 wait syz-executor.1 53811 415403 76173 32767 3 0x90 nanoslp syz-executor.0 76173 218553 84675 0 3 0x82 wait syz-executor.0 84675 119474 58481 0 3 0x82 wait syz-fuzzer 84675 437310 58481 0 3 0x4000082 nanoslp syz-fuzzer 84675 163700 58481 0 3 0x4000082 wait syz-fuzzer 84675 411282 58481 0 3 0x4000082 thrsleep syz-fuzzer 84675 18750 58481 0 3 0x4000082 wait syz-fuzzer 84675 148147 58481 0 3 0x4000082 wait syz-fuzzer 84675 88417 58481 0 3 0x4000082 thrsleep syz-fuzzer 84675 144972 58481 0 3 0x4000082 thrsleep syz-fuzzer 84675 116490 58481 0 3 0x4000082 wait syz-fuzzer 84675 523580 58481 0 3 0x4000082 wait syz-fuzzer 84675 514744 58481 0 3 0x4000082 wait syz-fuzzer 84675 67239 58481 0 3 0x4000082 wait syz-fuzzer 84675 314852 58481 0 3 0x4000082 thrsleep syz-fuzzer 84675 43165 58481 0 3 0x4000082 thrsleep syz-fuzzer 84675 357392 58481 0 3 0x4000082 nanoslp syz-fuzzer 84675 152075 58481 0 3 0x4000082 kqread syz-fuzzer 58481 313384 80850 0 3 0x10008a sigsusp ksh 80850 449034 65382 0 3 0x9a kqread sshd 3642 35946 1 0 3 0x100083 ttyin getty 65382 430273 1 0 3 0x88 kqread sshd 16420 410655 43382 73 3 0x1100090 kqread syslogd 43382 469360 1 0 3 0x100082 netio syslogd 3456 159040 1 0 3 0x100080 kqread resolvd 22270 288021 9986 77 3 0x100092 kqread dhcpleased 77239 502823 9986 77 3 0x100092 kqread dhcpleased 9986 125540 1 0 3 0x80 kqread dhcpleased 47496 452517 0 0 3 0x14200 bored smr 48195 487657 0 0 2 0x14200 zerothread 93492 21233 0 0 3 0x14200 aiodoned aiodoned 35283 8872 0 0 3 0x14200 syncer update 86727 134782 0 0 3 0x14200 cleaner cleaner 64051 220304 0 0 3 0x14200 reaper reaper 60640 401666 0 0 3 0x14200 pgdaemon pagedaemon 53968 74581 0 0 3 0x14200 bored viomb 9726 227025 0 0 3 0x40014200 acpi0 acpi0 40894 142381 0 0 3 0x40014200 idle1 2719 78464 0 0 3 0x14200 bored softnet 61482 363955 0 0 3 0x14200 bored softnet 22708 368385 0 0 3 0x14200 bored softnet 86334 229301 0 0 3 0x14200 bored softnet 4081 438847 0 0 3 0x14200 bored systqmp 94066 151151 0 0 3 0x14200 bored systq 89478 164430 0 0 3 0x40014200 bored softclock 44820 59986 0 0 3 0x40014200 idle0 1 405972 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb{1}> show all locks Process 55207 (syz-executor.4) thread 0xffff8000fffef510 (22811) exclusive rwlock netlock r = 0 (0xffffffff8292fbb0) #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{1}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim devbuf 10200 6410K 6419K 78643K 11291 0 pcb 13 12K 14K 78643K 17 0 rtable 240 6K 7K 78643K 441 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 101 0 iov 0 0K 12K 78643K 230 0 mount 1 1K 1K 78643K 1 0 log 0 0K 0K 78643K 4 0 vnodes 1270 79K 79K 78643K 1490 0 UFS quota 1 32K 32K 78643K 1 0 UFS mount 5 36K 36K 78643K 5 0 shm 2 1K 5K 78643K 17 0 VM map 2 1K 1K 78643K 2 0 sem 12 0K 0K 78643K 299 0 dirhash 12 2K 2K 78643K 12 0 ACPI 1697 195K 286K 78643K 12548 0 file desc 26 97K 121K 78643K 1579 0 sigio 0 0K 0K 78643K 47 0 proc 56 78K 115K 78643K 610 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 51 0 in_multi 99 6K 6K 78643K 109 0 ether_multi 1 0K 0K 78643K 4 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 181 811K 811K 78643K 181 0 exec 0 0K 2K 78643K 905 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 265 83K 99K 78643K 11128 0 UVM aobj 42 2K 2K 78643K 42 0 memdesc 1 4K 4K 78643K 1 0 crypto data 1 1K 1K 78643K 1 0 ip6_options 0 0K 0K 78643K 34 0 NDP 11 0K 2K 78643K 27 0 temp 124 4726K 4854K 78643K 6595 0 kqueue 12 18K 22K 78643K 138 0 SYN cache 2 16K 16K 78643K 2 0 ddb{1}> 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 120 110 0 107 1 0 1 1 0 8 0 rtentry 112 114 0 1 4 0 4 4 0 8 0 unpcb 144 2140 0 2127 20 19 1 10 0 8 0 syncache 296 34 0 34 4 3 1 1 0 8 1 tcpqe 32 204 0 204 5 4 1 1 0 8 1 tcpcb 768 762 0 751 29 26 3 15 0 8 0 arp 120 19 0 0 1 0 1 1 0 8 0 inpcb 368 4367 0 4349 46 38 8 14 0 8 5 nd6 48 26 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 256 468 0 0 30 0 30 30 0 8 0 art_table 32 469 0 0 4 0 4 4 0 8 0 art_node 16 113 0 10 1 0 1 1 0 8 0 sysvmsgpl 40 3 0 3 1 1 0 1 0 8 0 semupl 112 3 0 3 1 1 0 1 0 8 0 semapl 112 297 0 287 1 0 1 1 0 8 0 shmpl 112 39 0 0 2 0 2 2 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino2pl 256 3472 0 2035 91 0 91 91 0 8 0 ffsino 272 3472 0 2035 97 0 97 97 0 8 0 nchpl 144 5703 0 4031 63 0 63 63 0 8 0 uvmvnodes 80 3585 0 0 74 0 74 74 0 8 0 vnodes 216 3585 0 0 200 0 200 200 0 8 0 namei 1024 19645 0 19645 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 16325 0 16325 11 10 1 8 0 8 1 plimitpl 152 540 0 518 2 1 1 2 0 8 0 sigapl 424 1866 0 1811 7 0 7 7 0 8 0 futexpl 64 14983 0 14980 1 0 1 1 0 8 0 knotepl 120 333 0 0 10 0 10 10 0 8 0 kqueuepl 216 217 0 209 1 0 1 1 0 8 0 pipepl 320 571 0 542 15 12 3 9 0 8 0 fdescpl 496 1848 0 1811 7 2 5 6 0 8 0 filepl 152 14410 0 14171 32 20 12 19 0 8 2 lockfpl 104 171 0 168 1 0 1 1 0 8 0 lockfspl 48 54 0 51 1 0 1 1 0 8 0 sessionpl 144 23 0 7 1 0 1 1 0 8 0 pgrppl 48 58 0 42 1 0 1 1 0 8 0 ucredpl 104 1804 0 1786 1 0 1 1 0 8 0 zombiepl 144 1811 0 1811 1 0 1 1 0 8 1 processpl 1064 1866 0 1811 5 1 4 5 0 8 0 procpl 672 4948 0 4873 9 1 8 9 0 8 0 sosppl 168 29 0 29 2 2 0 1 0 8 0 sockpl 488 6697 0 6665 154 142 12 35 0 8 7 mcl64k 65536 17 0 0 3 0 3 3 0 8 0 mcl16k 16384 13 0 0 2 0 2 2 0 8 0 mcl12k 12288 10 0 0 1 0 1 1 0 8 0 mcl9k 9216 7 0 0 1 0 1 1 0 8 0 mcl8k 8192 17 0 0 3 0 3 3 0 8 0 mcl4k 4096 17 0 0 3 0 3 3 0 8 0 mcl2k2 2112 2 0 0 1 0 1 1 0 8 0 mcl2k 2048 321 0 0 40 0 40 40 0 8 0 mtagpl 96 3 0 0 1 0 1 1 0 8 0 mbufpl 256 381 0 0 23 0 23 23 0 8 0 bufpl 288 5726 0 124 401 0 401 401 0 8 0 anonpl 24 348056 0 335502 120 16 104 104 0 186 18 amapchunkpl 152 34315 0 33662 64 28 36 41 0 158 8 amappl16 200 4489 0 4114 40 12 28 33 0 8 7 amappl15 192 89 0 84 1 0 1 1 0 8 0 amappl14 184 180 0 176 1 0 1 1 0 8 0 amappl13 176 85 0 82 1 0 1 1 0 8 0 amappl12 168 189 0 181 1 0 1 1 0 8 0 amappl11 160 461 0 442 1 0 1 1 0 8 0 amappl10 152 211 0 204 1 0 1 1 0 8 0 amappl9 144 870 0 862 1 0 1 1 0 8 0 amappl8 136 768 0 703 3 0 3 3 0 8 0 amappl7 128 323 0 300 1 0 1 1 0 8 0 amappl6 120 568 0 555 2 1 1 2 0 8 0 amappl5 112 1383 0 1363 1 0 1 1 0 8 0 amappl4 104 1579 0 1538 3 1 2 3 0 8 0 amappl3 96 5272 0 5214 2 0 2 2 0 8 0 amappl2 88 500 0 467 2 0 2 2 0 8 0 amappl1 80 47784 0 47054 19 2 17 19 0 8 0 amappl 88 10580 0 10409 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 41 0 0 1 0 1 1 0 8 0 uaddrrnd 24 1848 0 1811 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 1848 0 1811 1 0 1 1 0 8 0 vmmpekpl 168 19134 0 19073 4 0 4 4 0 8 0 vmmpepl 168 182604 0 179780 142 3 139 139 0 357 12 vmsppl 368 1847 0 1811 4 0 4 4 0 8 0 rwobjpl 56 49281 0 44297 74 1 73 73 0 8 0 pdppl 4096 3703 0 3622 139 58 81 93 0 8 0 pvpl 32 753947 0 736312 246 62 184 233 0 265 32 pmappl 248 1847 0 1811 4 1 3 3 0 8 0 extentpl 40 56 0 38 1 0 1 1 0 8 0 phpool 112 891 0 99 23 0 23 23 0 8 0 ddb{1}> machine ddbcpu 0 Stopped at x86_ipi_db+0x1a: addq $0x8,%rsp x86_ipi_db(ffffffff82933ff0) 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: 0x7f7ffffd12d0, count: 12 ddb{0}> trace x86_ipi_db(ffffffff82933ff0) 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: 0x7f7ffffd12d0, count: -3 ddb{0}> machine ddbcpu 1 Stopped at db_enter+0x18: addq $0x8,%rsp db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:437 panic(ffffffff8257befc) at panic+0x177 sys/kern/subr_prf.c:198 tcp_output(ffff800000bb8000) at tcp_output+0x2cd2 sys/netinet/tcp_output.c:727 tcp_send(fffffd807df25ba8,fffffd807711da00,0,fffffd806e5c3300) at tcp_send+0xc4 sys/netinet/tcp_usrreq.c:953 sosend(fffffd807df25ba8,0,ffff800027bc0130,0,fffffd806e5c3300,0) at sosend+0x62a pru_send sys/sys/protosw.h:331 [inline] sosend(fffffd807df25ba8,0,ffff800027bc0130,0,fffffd806e5c3300,0) at sosend+0x62a sys/kern/uipc_socket.c:646 sendit(ffff8000fffef510,3,ffff800027bc02b0,0,ffff800027bc03a0) at sendit+0x65d sys/kern/uipc_syscalls.c:694 sys_sendmsg(ffff8000fffef510,ffff800027bc0358,ffff800027bc03a0) at sys_sendmsg+0x198 sys/kern/uipc_syscalls.c:601 syscall(ffff800027bc0420) at syscall+0x4c3 mi_syscall sys/sys/syscall_mi.h:101 [inline] syscall(ffff800027bc0420) at syscall+0x4c3 sys/arch/amd64/amd64/trap.c:585 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x9cdaac15d0, count: 6 ddb{1}> trace db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:437 panic(ffffffff8257befc) at panic+0x177 sys/kern/subr_prf.c:198 tcp_output(ffff800000bb8000) at tcp_output+0x2cd2 sys/netinet/tcp_output.c:727 tcp_send(fffffd807df25ba8,fffffd807711da00,0,fffffd806e5c3300) at tcp_send+0xc4 sys/netinet/tcp_usrreq.c:953 sosend(fffffd807df25ba8,0,ffff800027bc0130,0,fffffd806e5c3300,0) at sosend+0x62a pru_send sys/sys/protosw.h:331 [inline] sosend(fffffd807df25ba8,0,ffff800027bc0130,0,fffffd806e5c3300,0) at sosend+0x62a sys/kern/uipc_socket.c:646 sendit(ffff8000fffef510,3,ffff800027bc02b0,0,ffff800027bc03a0) at sendit+0x65d sys/kern/uipc_syscalls.c:694 sys_sendmsg(ffff8000fffef510,ffff800027bc0358,ffff800027bc03a0) at sys_sendmsg+0x198 sys/kern/uipc_syscalls.c:601 syscall(ffff800027bc0420) at syscall+0x4c3 mi_syscall sys/sys/syscall_mi.h:101 [inline] syscall(ffff800027bc0420) at syscall+0x4c3 sys/arch/amd64/amd64/trap.c:585 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x9cdaac15d0, count: -9