panic: tcp_output: template len != hdrlen - optlen Stopped at db_enter+0x18: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND 295877 23728 0 0x2 0x80 0 syz-executor.1 *517974 89198 0 0x12 0 1 sshd db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:398 panic(ffffffff8241707e) at panic+0x15c sys/kern/subr_prf.c:207 tcp_output(ffff800000ada320) at tcp_output+0x2c4b tcp_setpersist sys/netinet/tcp_output.c:1130 [inline] tcp_output(ffff800000ada320) at tcp_output+0x2c4b sys/netinet/tcp_output.c:333 tcp_usrreq(fffffd806eae5c88,9,fffffd806d77c200,0,0,ffff800020e40ae0) at tcp_usrreq+0xa55 sosend(fffffd806eae5c88,0,ffff800020e04d48,0,0,80) at sosend+0x671 sys/kern/uipc_socket.c:555 dofilewritev(ffff800020e40ae0,4,ffff800020e04d48,0,ffff800020e04e30) at dofilewritev+0x1b6 sys/kern/sys_generic.c:365 sys_write(ffff800020e40ae0,ffff800020e04de0,ffff800020e04e30) at sys_write+0x83 sys/kern/sys_generic.c:285 syscall(ffff800020e04eb0) at syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:102 [inline] syscall(ffff800020e04eb0) at syscall+0x4a4 sys/arch/amd64/amd64/trap.c:570 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7f7fffff08f0, 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 tcp_output: template len != hdrlen - optlen ddb{1}> trace db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:398 panic(ffffffff8241707e) at panic+0x15c sys/kern/subr_prf.c:207 tcp_output(ffff800000ada320) at tcp_output+0x2c4b tcp_setpersist sys/netinet/tcp_output.c:1130 [inline] tcp_output(ffff800000ada320) at tcp_output+0x2c4b sys/netinet/tcp_output.c:333 tcp_usrreq(fffffd806eae5c88,9,fffffd806d77c200,0,0,ffff800020e40ae0) at tcp_usrreq+0xa55 sosend(fffffd806eae5c88,0,ffff800020e04d48,0,0,80) at sosend+0x671 sys/kern/uipc_socket.c:555 dofilewritev(ffff800020e40ae0,4,ffff800020e04d48,0,ffff800020e04e30) at dofilewritev+0x1b6 sys/kern/sys_generic.c:365 sys_write(ffff800020e40ae0,ffff800020e04de0,ffff800020e04e30) at sys_write+0x83 sys/kern/sys_generic.c:285 syscall(ffff800020e04eb0) at syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:102 [inline] syscall(ffff800020e04eb0) at syscall+0x4a4 sys/arch/amd64/amd64/trap.c:570 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7f7fffff08f0, count: -9 ddb{1}> show registers rdi 0 rsi 0x1 rbp 0xffff800020e048b0 rbx 0xffff800020e04960 rdx 0x8b rcx 0x2 rax 0x1 r8 0xffffffff819395af kprintf+0x16f r9 0x1 r10 0x2 r11 0xff0b4572dfd06ef6 r12 0x3000000008 r13 0xffff800020e048c0 r14 0x100 r15 0x1 rip 0xffffffff818b7bb8 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff800020e048a0 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{1}> show proc PROC (sshd) pid=517974 stat=onproc flags process=12 proc=0 pri=24, usrpri=50, nice=20 forw=0xffffffffffffffff, list=0xffff800020e3f280,0xffff800020e3f770 process=0xffff8000fffff378 user=0xffff800020dff000, vmspace=0xfffffd806e8f7738 estcpu=0, cpticks=1, pctcpu=0.0 user=0, sys=1, intr=0 ddb{1}> ps PID TID PPID UID S FLAGS WAIT COMMAND 66750 75642 0 0 3 0x14200 bored sosplice 23728 295877 33595 0 7 0x82 syz-executor.1 17865 42719 33595 0 3 0x2 biowait syz-executor.0 33595 483937 97341 0 3 0x82 thrsleep syz-fuzzer 33595 341052 97341 0 3 0x4000082 nanosleep syz-fuzzer 33595 457020 97341 0 3 0x4000082 thrsleep syz-fuzzer 33595 435574 97341 0 3 0x4000082 thrsleep syz-fuzzer 33595 119857 97341 0 3 0x4000082 thrsleep syz-fuzzer 33595 357926 97341 0 3 0x4000082 thrsleep syz-fuzzer 33595 330247 97341 0 3 0x4000082 thrsleep syz-fuzzer 33595 441754 97341 0 3 0x4000082 thrsleep syz-fuzzer 33595 304347 97341 0 2 0x4000002 syz-fuzzer 33595 50584 97341 0 3 0x4000082 nanosleep syz-fuzzer 97341 225771 89198 0 3 0x10008a pause ksh *89198 517974 69329 0 7 0x12 sshd 50829 119343 1 0 3 0x100083 ttyin getty 69329 245131 1 0 3 0x80 select sshd 88988 104671 49947 74 3 0x100092 bpf pflogd 49947 58434 1 0 3 0x80 netio pflogd 92019 205083 18334 73 3 0x100090 kqread syslogd 18334 436774 1 0 3 0x100082 netio syslogd 25491 299158 1 77 3 0x100090 poll dhclient 54614 315953 1 0 3 0x80 poll dhclient 60975 90153 0 0 3 0x14200 bored smr 53144 258447 0 0 3 0x14200 pgzero zerothread 55859 383860 0 0 3 0x14200 aiodoned aiodoned 8383 445674 0 0 3 0x14200 syncer update 3294 232766 0 0 3 0x14200 cleaner cleaner 52364 20925 0 0 3 0x14200 reaper reaper 28300 301119 0 0 3 0x14200 pgdaemon pagedaemon 10754 101273 0 0 3 0x14200 bored crynlk 73277 453297 0 0 3 0x14200 bored crypto 37055 148662 0 0 3 0x40014200 acpi0 acpi0 73140 399830 0 0 3 0x40014200 idle1 49115 127356 0 0 3 0x14200 bored softnet 82116 171488 0 0 3 0x14200 bored systqmp 84576 21034 0 0 3 0x14200 bored systq 49746 199777 0 0 3 0x40014200 bored softclock 83428 441907 0 0 3 0x40014200 idle0 1 9465 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb{1}> show all locks Process 17865 (syz-executor.0) thread 0xffff800020ddd868 (42719) exclusive rrwlock inode r = 0 (0xfffffd8069f6f3d0) #0 witness_lock+0x4c7 stacktrace_save sys/sys/stacktrace.h:36 [inline] #0 witness_lock+0x4c7 sys/kern/subr_witness.c:1164 #1 rw_enter+0x453 sys/kern/kern_rwlock.c:311 #2 rrw_enter+0x88 sys/kern/kern_rwlock.c:462 #3 VOP_LOCK+0x4b sys/kern/vfs_vops.c:603 #4 vn_lock+0x81 sys/kern/vfs_vnops.c:575 #5 vget+0x1c8 sys/kern/vfs_subr.c:671 #6 ufs_ihashget+0x141 sys/ufs/ufs/ufs_ihash.c:119 #7 ffs_vget+0x74 sys/ufs/ffs/ffs_vfsops.c:1329 #8 ufs_lookup+0x14b7 sys/ufs/ufs/ufs_lookup.c:487 #9 VOP_LOOKUP+0x5b sys/kern/vfs_vops.c:90 #10 vfs_lookup+0x7a6 sys/kern/vfs_lookup.c:568 #11 namei+0x63c sys/kern/vfs_lookup.c:249 #12 dounlinkat+0x99 sys/kern/vfs_syscalls.c:1853 #13 syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:102 [inline] #13 syscall+0x4a4 sys/arch/amd64/amd64/trap.c:570 #14 Xsyscall+0x128 exclusive rrwlock inode r = 0 (0xfffffd8069f6fa30) #0 witness_lock+0x4c7 stacktrace_save sys/sys/stacktrace.h:36 [inline] #0 witness_lock+0x4c7 sys/kern/subr_witness.c:1164 #1 rw_enter+0x453 sys/kern/kern_rwlock.c:311 #2 rrw_enter+0x88 sys/kern/kern_rwlock.c:462 #3 VOP_LOCK+0x4b sys/kern/vfs_vops.c:603 #4 vn_lock+0x81 sys/kern/vfs_vnops.c:575 #5 vfs_lookup+0xe6 sys/kern/vfs_lookup.c:419 #6 namei+0x63c sys/kern/vfs_lookup.c:249 #7 dounlinkat+0x99 sys/kern/vfs_syscalls.c:1853 #8 syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:102 [inline] #8 syscall+0x4a4 sys/arch/amd64/amd64/trap.c:570 #9 Xsyscall+0x128 Process 89198 (sshd) thread 0xffff800020e40ae0 (517974) exclusive rwlock netlock r = 0 (0xffffffff8274fbe8) #0 witness_lock+0x4c7 stacktrace_save sys/sys/stacktrace.h:36 [inline] #0 witness_lock+0x4c7 sys/kern/subr_witness.c:1164 #1 solock+0x5a sys/kern/uipc_socket2.c:282 #2 sosend+0x559 sys/kern/uipc_socket.c:543 #3 dofilewritev+0x1b6 sys/kern/sys_generic.c:365 #4 sys_write+0x83 sys/kern/sys_generic.c:285 #5 syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:102 [inline] #5 syscall+0x4a4 sys/arch/amd64/amd64/trap.c:570 #6 Xsyscall+0x128 ddb{1}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim devbuf 9505 6410K 6792K 78643K 10761 0 pcb 13 8K 8K 78643K 45 0 rtable 116 6K 7K 78643K 295 0 ifaddr 63 13K 13K 78643K 93 0 counters 43 33K 34K 78643K 49 0 ioctlops 0 0K 4K 78643K 1496 0 iov 0 0K 12K 78643K 84 0 mount 1 1K 1K 78643K 1 0 vnodes 1220 77K 77K 78643K 1271 0 UFS quota 1 32K 32K 78643K 1 0 UFS mount 5 36K 36K 78643K 5 0 shm 2 1K 5K 78643K 3 0 VM map 2 1K 1K 78643K 2 0 sem 12 0K 0K 78643K 32 0 dirhash 12 2K 2K 78643K 12 0 ACPI 1824 197K 290K 78643K 13058 0 file desc 4 9K 25K 78643K 160 0 sigio 0 0K 0K 78643K 2 0 proc 61 63K 95K 78643K 448 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 15 0 in_multi 33 2K 2K 78643K 69 0 ether_multi 1 0K 0K 78643K 4 0 mrt 0 0K 0K 78643K 6 0 ISOFS mount 1 32K 32K 78643K 1 0 MSDOSFS mount 1 16K 16K 78643K 1 0 ttys 49 228K 228K 78643K 49 0 exec 0 0K 1K 78643K 215 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 116 55K 67K 78643K 1441 0 UVM aobj 9 2K 2K 78643K 9 0 memdesc 1 4K 4K 78643K 1 0 crypto data 1 1K 1K 78643K 1 0 ip6_options 0 0K 0K 78643K 23 0 NDP 10 0K 0K 78643K 20 0 temp 92 3863K 3927K 78643K 2370 0 kqueue 3 4K 8K 78643K 7 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 arp 64 6 0 0 1 0 1 1 0 8 0 plcache 128 20 0 0 1 0 1 1 0 8 0 rtpcb 80 27 0 25 1 0 1 1 0 8 0 rtentry 112 57 0 15 2 0 2 2 0 8 0 unpcb 120 119 0 109 1 0 1 1 0 8 0 syncache 264 4 0 4 1 1 0 1 0 8 0 tcpqe 32 709 0 709 1 1 0 1 0 8 0 tcpcb 544 48 0 44 1 0 1 1 0 8 0 inpcb 296 285 0 277 3 1 2 2 0 8 1 rttmr 72 2 0 2 1 0 1 1 0 8 1 nd6 48 13 0 8 1 0 1 1 0 8 0 pkpcb 40 2 0 2 1 1 0 1 0 8 0 ppxss 1128 1 0 1 1 0 1 1 0 8 1 pffrag 232 1 0 1 1 1 0 1 0 482 0 pffrnode 88 1 0 1 1 1 0 1 0 8 0 pffrent 40 45 0 45 1 1 0 1 0 8 0 pfosfp 40 846 0 423 5 0 5 5 0 8 0 pfosfpen 112 1428 0 714 21 0 21 21 0 8 0 pfrktable 1344 12 0 8 2 1 1 1 0 8 0 pfstitem 24 19 0 5 1 0 1 1 0 8 0 pfstkey 112 19 0 5 1 0 1 1 0 8 0 pfstate 328 19 0 5 2 0 2 2 0 8 0 pfrule 1360 29 0 18 2 1 1 2 0 8 0 art_heap8 4096 1 0 0 1 0 1 1 0 8 0 art_heap4 256 233 0 54 12 0 12 12 0 8 0 art_table 32 234 0 54 2 0 2 2 0 8 0 art_node 16 56 0 17 1 0 1 1 0 8 0 sysvmsgpl 40 8 0 2 1 0 1 1 0 8 0 semupl 112 2 0 2 1 0 1 1 0 8 1 semapl 112 29 0 19 1 0 1 1 0 8 0 shmpl 112 6 0 0 1 0 1 1 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino2pl 256 1592 0 186 89 0 89 89 0 8 1 ffsino 272 1592 0 186 95 1 94 94 0 8 0 nchpl 144 2022 0 413 61 0 61 61 0 8 1 uvmvnodes 72 1674 0 0 31 0 31 31 0 8 0 vnodes 208 1674 0 0 89 0 89 89 0 8 0 namei 1024 5408 0 5408 3 2 1 1 0 8 1 percpumem 16 35 0 3 1 0 1 1 0 8 0 vcpupl 1984 3 0 0 1 0 1 1 0 8 0 vmpool 560 7 0 4 1 0 1 1 0 8 0 pfiaddrpl 120 6 0 2 2 1 1 1 0 8 0 scxspl 192 6105 0 6104 10 8 2 7 0 8 1 plimitpl 152 27 0 19 1 0 1 1 0 8 0 sigapl 424 376 0 345 4 0 4 4 0 8 0 futexpl 56 2046 0 2046 2 1 1 1 0 8 1 knotepl 112 69 0 50 1 0 1 1 0 8 0 kqueuepl 144 16 0 14 1 0 1 1 0 8 0 pipepl 304 91 0 81 1 0 1 1 0 8 0 fdescpl 496 360 0 345 3 0 3 3 0 8 0 filepl 152 2040 0 1940 6 1 5 5 0 8 1 lockfpl 104 23 0 22 1 0 1 1 0 8 0 lockfspl 48 10 0 9 1 0 1 1 0 8 0 sessionpl 112 18 0 7 1 0 1 1 0 8 0 pgrppl 48 18 0 7 1 0 1 1 0 8 0 ucredpl 96 148 0 139 1 0 1 1 0 8 0 zombiepl 144 345 0 345 2 1 1 1 0 8 1 processpl 992 376 0 345 6 1 5 5 0 8 0 procpl 624 681 0 641 4 0 4 4 0 8 0 sosppl 128 3 0 3 1 0 1 1 0 8 1 sockpl 400 434 0 415 5 1 4 4 0 8 2 mcl64k 65536 4 0 0 1 0 1 1 0 8 0 mcl16k 16384 1 0 0 1 0 1 1 0 8 0 mcl12k 12288 2 0 0 1 0 1 1 0 8 0 mcl9k 9216 2 0 0 1 0 1 1 0 8 0 mcl8k 8192 1 0 0 1 0 1 1 0 8 0 mcl4k 4096 3 0 0 1 0 1 1 0 8 0 mcl2k 2048 215 0 0 26 0 26 26 0 8 0 mtagpl 96 14 0 0 1 0 1 1 0 8 0 mbufpl 256 252 0 0 16 0 16 16 0 8 0 bufpl 280 3704 0 132 256 0 256 256 0 8 0 anonpl 16 52572 0 35857 83 1 82 82 0 124 14 amapchunkpl 152 1769 0 1608 9 1 8 9 0 158 0 amappl16 192 1798 0 917 55 2 53 55 0 8 8 amappl15 184 9 0 7 1 0 1 1 0 8 0 amappl14 176 31 0 25 1 0 1 1 0 8 0 amappl13 168 28 0 25 1 0 1 1 0 8 0 amappl12 160 9 0 6 1 0 1 1 0 8 0 amappl11 152 50 0 35 1 0 1 1 0 8 0 amappl10 144 19 0 14 1 0 1 1 0 8 0 amappl9 136 514 0 511 1 0 1 1 0 8 0 amappl8 128 402 0 376 1 0 1 1 0 8 0 amappl7 120 116 0 106 1 0 1 1 0 8 0 amappl6 112 30 0 24 1 0 1 1 0 8 0 amappl5 104 253 0 239 1 0 1 1 0 8 0 amappl4 96 484 0 457 1 0 1 1 0 8 0 amappl3 88 107 0 101 1 0 1 1 0 8 0 amappl2 80 1924 0 1862 2 0 2 2 0 8 0 amappl1 72 17843 0 17417 23 13 10 18 0 8 0 amappl 80 931 0 886 2 0 2 2 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 8 0 0 1 0 1 1 0 8 0 uaddrrnd 24 367 0 349 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 367 0 349 1 0 1 1 0 8 0 vmmpekpl 168 6860 0 6824 2 0 2 2 0 8 0 vmmpepl 168 51987 0 50051 127 13 114 115 0 357 20 vmsppl 368 366 0 349 2 0 2 2 0 8 0 pdppl 4096 741 0 701 7 1 6 6 0 8 0 pvpl 32 168492 0 148725 193 0 193 193 0 265 30 pmappl 232 366 0 349 3 1 2 2 0 8 0 extentpl 40 53 0 36 1 0 1 1 0 8 0 phpool 112 272 0 8 8 0 8 8 0 8 0 ddb{1}> machine ddbcpu 0 Stopped at x86_ipi_db+0x1a: addq $0x8,%rsp x86_ipi_db(ffffffff8270eff0) at x86_ipi_db+0x1a sys/arch/amd64/amd64/db_interface.c:352 x86_ipi_handler() at x86_ipi_handler+0xc6 sys/arch/amd64/amd64/ipi.c:106 Xresume_lapic_ipi() at Xresume_lapic_ipi+0x23 __mp_lock(ffffffff829011d8) at __mp_lock+0x127 __mp_lock_spin sys/kern/kern_lock.c:116 [inline] __mp_lock(ffffffff829011d8) at __mp_lock+0x127 sys/kern/kern_lock.c:147 __mp_acquire_count(ffffffff829011d8,1) at __mp_acquire_count+0x51 sys/kern/kern_lock.c:227 mi_switch() at mi_switch+0x392 sys/kern/sched_bsd.c:435 sleep_finish(ffff8000230faf40,1) at sleep_finish+0x113 sys/kern/kern_synch.c:418 sleep_finish_all(ffff8000230faf40,1) at sleep_finish_all+0x32 sleep_finish_timeout sys/kern/kern_synch.c:447 [inline] sleep_finish_all(ffff8000230faf40,1) at sleep_finish_all+0x32 sys/kern/kern_synch.c:393 rwsleep(fffffd807aac0670,fffffd807aac06f0,110,ffffffff824823cc,0) at rwsleep+0x11b sys/kern/kern_synch.c:313 pipe_iosleep(fffffd807aac0670,ffffffff824823cc) at pipe_iosleep+0xad sys/kern/sys_pipe.c:348 pipe_read(fffffd80675fab68,ffff8000230fb148,0) at pipe_read+0x290 sys/kern/sys_pipe.c:446 dofilereadv(ffff800020e0aae8,f9,ffff8000230fb148,0,ffff8000230fb230) at dofilereadv+0x1a1 sys/kern/sys_generic.c:237 sys_read(ffff800020e0aae8,ffff8000230fb1e0,ffff8000230fb230) at sys_read+0x83 sys/kern/sys_generic.c:157 syscall(ffff8000230fb2b0) at syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:102 [inline] syscall(ffff8000230fb2b0) at syscall+0x4a4 sys/arch/amd64/amd64/trap.c:570 end trace frame: 0xffff8000230fb330, count: 0 ddb{0}> trace x86_ipi_db(ffffffff8270eff0) at x86_ipi_db+0x1a sys/arch/amd64/amd64/db_interface.c:352 x86_ipi_handler() at x86_ipi_handler+0xc6 sys/arch/amd64/amd64/ipi.c:106 Xresume_lapic_ipi() at Xresume_lapic_ipi+0x23 __mp_lock(ffffffff829011d8) at __mp_lock+0x127 __mp_lock_spin sys/kern/kern_lock.c:116 [inline] __mp_lock(ffffffff829011d8) at __mp_lock+0x127 sys/kern/kern_lock.c:147 __mp_acquire_count(ffffffff829011d8,1) at __mp_acquire_count+0x51 sys/kern/kern_lock.c:227 mi_switch() at mi_switch+0x392 sys/kern/sched_bsd.c:435 sleep_finish(ffff8000230faf40,1) at sleep_finish+0x113 sys/kern/kern_synch.c:418 sleep_finish_all(ffff8000230faf40,1) at sleep_finish_all+0x32 sleep_finish_timeout sys/kern/kern_synch.c:447 [inline] sleep_finish_all(ffff8000230faf40,1) at sleep_finish_all+0x32 sys/kern/kern_synch.c:393 rwsleep(fffffd807aac0670,fffffd807aac06f0,110,ffffffff824823cc,0) at rwsleep+0x11b sys/kern/kern_synch.c:313 pipe_iosleep(fffffd807aac0670,ffffffff824823cc) at pipe_iosleep+0xad sys/kern/sys_pipe.c:348 pipe_read(fffffd80675fab68,ffff8000230fb148,0) at pipe_read+0x290 sys/kern/sys_pipe.c:446 dofilereadv(ffff800020e0aae8,f9,ffff8000230fb148,0,ffff8000230fb230) at dofilereadv+0x1a1 sys/kern/sys_generic.c:237 sys_read(ffff800020e0aae8,ffff8000230fb1e0,ffff8000230fb230) at sys_read+0x83 sys/kern/sys_generic.c:157 syscall(ffff8000230fb2b0) at syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:102 [inline] syscall(ffff8000230fb2b0) at syscall+0x4a4 sys/arch/amd64/amd64/trap.c:570 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7f7fffff00d0, count: -15 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:398 panic(ffffffff8241707e) at panic+0x15c sys/kern/subr_prf.c:207 tcp_output(ffff800000ada320) at tcp_output+0x2c4b tcp_setpersist sys/netinet/tcp_output.c:1130 [inline] tcp_output(ffff800000ada320) at tcp_output+0x2c4b sys/netinet/tcp_output.c:333 tcp_usrreq(fffffd806eae5c88,9,fffffd806d77c200,0,0,ffff800020e40ae0) at tcp_usrreq+0xa55 sosend(fffffd806eae5c88,0,ffff800020e04d48,0,0,80) at sosend+0x671 sys/kern/uipc_socket.c:555 dofilewritev(ffff800020e40ae0,4,ffff800020e04d48,0,ffff800020e04e30) at dofilewritev+0x1b6 sys/kern/sys_generic.c:365 sys_write(ffff800020e40ae0,ffff800020e04de0,ffff800020e04e30) at sys_write+0x83 sys/kern/sys_generic.c:285 syscall(ffff800020e04eb0) at syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:102 [inline] syscall(ffff800020e04eb0) at syscall+0x4a4 sys/arch/amd64/amd64/trap.c:570 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7f7fffff08f0, count: 6 ddb{1}> trace db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:398 panic(ffffffff8241707e) at panic+0x15c sys/kern/subr_prf.c:207 tcp_output(ffff800000ada320) at tcp_output+0x2c4b tcp_setpersist sys/netinet/tcp_output.c:1130 [inline] tcp_output(ffff800000ada320) at tcp_output+0x2c4b sys/netinet/tcp_output.c:333 tcp_usrreq(fffffd806eae5c88,9,fffffd806d77c200,0,0,ffff800020e40ae0) at tcp_usrreq+0xa55 sosend(fffffd806eae5c88,0,ffff800020e04d48,0,0,80) at sosend+0x671 sys/kern/uipc_socket.c:555 dofilewritev(ffff800020e40ae0,4,ffff800020e04d48,0,ffff800020e04e30) at dofilewritev+0x1b6 sys/kern/sys_generic.c:365 sys_write(ffff800020e40ae0,ffff800020e04de0,ffff800020e04e30) at sys_write+0x83 sys/kern/sys_generic.c:285 syscall(ffff800020e04eb0) at syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:102 [inline] syscall(ffff800020e04eb0) at syscall+0x4a4 sys/arch/amd64/amd64/trap.c:570 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7f7fffff08f0, count: -9