panic: syn_cache_insert: bucketoverflow: impossible Stopped at db_enter+0x18: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND *355592 96885 0 0x14000 0x200 0 softnet db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:398 panic(ffffffff823abf38) at panic+0x15c sys/kern/subr_prf.c:207 syn_cache_insert(fffffd8060087c70,ffff800000abf440) at syn_cache_insert+0x944 sys/netinet/tcp_input.c:3235 syn_cache_add(ffff80001d6787f8,ffff80001d6787a8,fffffd8006042068,28,fffffd80658d8c80,fffffd80581f6f00) at syn_cache_add+0x66b tcp_input(ffff80001d678b28,ffff80001d678b34,6,18) at tcp_input+0x37d8 sys/netinet/tcp_input.c:830 ip_deliver(ffff80001d678b28,ffff80001d678b34,6,18) at ip_deliver+0x2e3 sys/netinet/ip_input.c:668 ip6_input_if(ffff80001d678b28,ffff80001d678b34,29,0,ffff800000677800) at ip6_input_if+0x1526 ip6_ours sys/netinet6/ip6_input.c:538 [inline] ip6_input_if(ffff80001d678b28,ffff80001d678b34,29,0,ffff800000677800) at ip6_input_if+0x1526 sys/netinet6/ip6_input.c:471 ipv6_input(ffff800000677800,fffffd80581f6f00) at ipv6_input+0x48 sys/netinet6/ip6_input.c:171 if_input_local(ffff800000677800,fffffd80581f6f00,18) at if_input_local+0x121 sys/net/if.c:779 loinput(ffff800000677800,fffffd80581f6f00,0) at loinput+0x4f sys/net/if_loop.c:239 if_input_process(ffff800000677800,ffff80001d678c78) at if_input_process+0xf8 if_ih_input sys/net/if.c:908 [inline] if_input_process(ffff800000677800,ffff80001d678c78) at if_input_process+0xf8 sys/net/if.c:942 ifiq_process(ffff800000677bb8) at ifiq_process+0x80 sys/net/ifq.c:646 taskq_thread(ffff80000002b080) at taskq_thread+0x92 sys/kern/kern_task.c:438 end trace frame: 0x0, count: 2 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 syn_cache_insert: bucketoverflow: impossible ddb> trace db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:398 panic(ffffffff823abf38) at panic+0x15c sys/kern/subr_prf.c:207 syn_cache_insert(fffffd8060087c70,ffff800000abf440) at syn_cache_insert+0x944 sys/netinet/tcp_input.c:3235 syn_cache_add(ffff80001d6787f8,ffff80001d6787a8,fffffd8006042068,28,fffffd80658d8c80,fffffd80581f6f00) at syn_cache_add+0x66b tcp_input(ffff80001d678b28,ffff80001d678b34,6,18) at tcp_input+0x37d8 sys/netinet/tcp_input.c:830 ip_deliver(ffff80001d678b28,ffff80001d678b34,6,18) at ip_deliver+0x2e3 sys/netinet/ip_input.c:668 ip6_input_if(ffff80001d678b28,ffff80001d678b34,29,0,ffff800000677800) at ip6_input_if+0x1526 ip6_ours sys/netinet6/ip6_input.c:538 [inline] ip6_input_if(ffff80001d678b28,ffff80001d678b34,29,0,ffff800000677800) at ip6_input_if+0x1526 sys/netinet6/ip6_input.c:471 ipv6_input(ffff800000677800,fffffd80581f6f00) at ipv6_input+0x48 sys/netinet6/ip6_input.c:171 if_input_local(ffff800000677800,fffffd80581f6f00,18) at if_input_local+0x121 sys/net/if.c:779 loinput(ffff800000677800,fffffd80581f6f00,0) at loinput+0x4f sys/net/if_loop.c:239 if_input_process(ffff800000677800,ffff80001d678c78) at if_input_process+0xf8 if_ih_input sys/net/if.c:908 [inline] if_input_process(ffff800000677800,ffff80001d678c78) at if_input_process+0xf8 sys/net/if.c:942 ifiq_process(ffff800000677bb8) at ifiq_process+0x80 sys/net/ifq.c:646 taskq_thread(ffff80000002b080) at taskq_thread+0x92 sys/kern/kern_task.c:438 end trace frame: 0x0, count: -13 ddb> show registers rdi 0 rsi 0x1 rbp 0xffff80001d678370 rbx 0xffff80001d678420 rdx 0x2 rcx 0 rax 0x1 r8 0xffffffff814fdcef kprintf+0x15f r9 0x1 r10 0x2 r11 0x9dc01df6f5c61bc0 r12 0x3000000008 r13 0xffff80001d678380 r14 0x100 r15 0x1 rip 0xffffffff82018d68 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff80001d678360 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb> show proc PROC (softnet) pid=355592 stat=onproc flags process=14000 proc=200 pri=32, usrpri=50, nice=20 forw=0xffffffffffffffff, list=0xffff80001d652110,0xffff80001d6514f0 process=0xffff8000fffff1f8 user=0xffff80001d673000, vmspace=0xffffffff827f3770 estcpu=0, cpticks=1, pctcpu=0.37 user=0, sys=1, intr=0 ddb> ps PID TID PPID UID S FLAGS WAIT COMMAND 41209 292373 47792 0 2 0 syz-executor.0 41209 230033 47792 0 3 0x4000080 netcon2 syz-executor.0 37801 111420 0 0 3 0x14200 bored sosplice 22428 184806 64505 0 2 0x482 syz-executor.1 75565 189920 0 0 3 0x14200 acct acct 47792 60871 64505 0 2 0x482 syz-executor.0 64505 95914 34536 0 3 0x82 thrsleep syz-fuzzer 64505 278587 34536 0 3 0x4000082 thrsleep syz-fuzzer 64505 501856 34536 0 3 0x4000082 kqread syz-fuzzer 64505 407812 34536 0 3 0x4000082 thrsleep syz-fuzzer 64505 14721 34536 0 3 0x4000082 thrsleep syz-fuzzer 64505 218912 34536 0 3 0x4000082 thrsleep syz-fuzzer 64505 102138 34536 0 3 0x4000082 thrsleep syz-fuzzer 64505 471909 34536 0 3 0x4000082 thrsleep syz-fuzzer 34536 458209 20602 0 3 0x10008a pause ksh 20602 57160 16306 0 3 0x92 select sshd 71367 497198 1 0 3 0x100083 ttyin getty 16306 331784 1 0 3 0x80 select sshd 20888 284702 70848 73 3 0x100090 kqread syslogd 70848 159228 1 0 3 0x100082 netio syslogd 70970 369951 1 77 3 0x100090 poll dhclient 24947 230666 1 0 3 0x80 poll dhclient 48112 261597 0 0 3 0x14200 bored smr 63388 99831 0 0 2 0x14200 zerothread 93929 447984 0 0 3 0x14200 aiodoned aiodoned 5394 440489 0 0 3 0x14200 syncer update 41096 218287 0 0 3 0x14200 cleaner cleaner 48793 353117 0 0 3 0x14200 reaper reaper 28995 55836 0 0 3 0x14200 pgdaemon pagedaemon 47426 447595 0 0 3 0x14200 bored crynlk 67599 392737 0 0 3 0x14200 bored crypto 73731 372859 0 0 3 0x40014200 acpi0 acpi0 *96885 355592 0 0 7 0x14200 softnet 79677 88769 0 0 3 0x14200 bored systqmp 18401 99039 0 0 3 0x14200 bored systq 91011 158038 0 0 3 0x40014200 bored softclock 49288 104467 0 0 3 0x40014200 idle0 1 119720 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 9496 6342K 6726K 78643K 11099 0 pcb 13 8K 8K 78643K 51 0 rtable 111 5K 7K 78643K 393 0 ifaddr 79 16K 16K 78643K 130 0 counters 21 16K 16K 78643K 24 0 ioctlops 0 0K 4K 78643K 72 0 iov 0 0K 12K 78643K 36 0 mount 1 1K 1K 78643K 1 0 vnodes 1216 76K 77K 78643K 1383 0 UFS quota 1 32K 32K 78643K 1 0 UFS mount 5 36K 36K 78643K 5 0 shm 2 1K 5K 78643K 4 0 VM map 2 0K 0K 78643K 2 0 sem 12 0K 0K 78643K 60 0 dirhash 12 2K 2K 78643K 12 0 ACPI 1809 195K 288K 78643K 12938 0 file desc 5 13K 25K 78643K 310 0 sigio 0 0K 0K 78643K 101 0 proc 49 38K 63K 78643K 407 0 subproc 32 2K 2K 78643K 53 0 NFS srvsock 1 0K 0K 78643K 1 0 NFS daemon 1 16K 16K 78643K 1 0 ip_moptions 0 0K 0K 78643K 94 0 in_multi 67 3K 3K 78643K 110 0 ether_multi 1 0K 0K 78643K 6 0 ISOFS mount 1 32K 32K 78643K 1 0 MSDOSFS mount 1 16K 16K 78643K 1 0 ttys 43 201K 201K 78643K 43 0 exec 0 0K 1K 78643K 218 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 130 55K 55K 78643K 1568 0 UVM aobj 6 2K 2K 78643K 10 0 memdesc 1 4K 4K 78643K 1 0 crypto data 1 1K 1K 78643K 1 0 ip6_options 0 0K 0K 78643K 55 0 NDP 11 0K 0K 78643K 21 0 temp 93 3843K 3907K 78643K 11968 0 kqueue 3 4K 10K 78643K 18 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 arp 64 9 0 3 1 0 1 1 0 8 0 rtpcb 80 39 0 37 1 0 1 1 0 8 0 rtentry 112 64 0 22 2 0 2 2 0 8 0 unpcb 120 139 0 131 1 0 1 1 0 8 0 syncache 264 5 0 4 3 2 1 1 0 8 0 tcpqe 32 170 0 170 2 2 0 1 0 8 0 tcpcb 544 248 0 241 2 0 2 2 0 8 1 inpcb 280 513 0 503 2 0 2 2 0 8 1 ip6q 72 2 0 2 1 0 1 1 0 8 1 ip6af 40 6 0 6 1 0 1 1 0 8 1 nd6 48 10 0 6 1 0 1 1 0 8 0 pkpcb 40 2 0 2 1 0 1 1 0 8 1 pfstscr 40 6 0 2 1 0 1 1 0 8 0 pfrktable 1344 44 0 41 1 0 1 1 0 8 0 pftag 88 8 0 8 2 1 1 1 0 8 1 pfstitem 24 6 0 0 1 0 1 1 0 8 0 pfstkey 112 8 0 2 1 0 1 1 0 8 0 pfstate 328 4 0 1 1 0 1 1 0 8 0 pfrule 1360 20 0 8 1 0 1 1 0 8 0 art_heap8 4096 2 0 0 2 0 2 2 0 8 0 art_heap4 256 266 0 86 13 1 12 13 0 8 0 art_table 32 268 0 86 2 0 2 2 0 8 0 art_node 16 63 0 24 1 0 1 1 0 8 0 sysvmsgpl 40 9 0 4 1 0 1 1 0 8 0 semupl 112 1 0 1 1 1 0 1 0 8 0 semapl 112 56 0 46 1 0 1 1 0 8 0 shmpl 112 8 0 4 1 0 1 1 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino2pl 256 1807 0 409 88 0 88 88 0 8 0 ffsino 240 1807 0 409 83 0 83 83 0 8 0 nchpl 144 2438 0 848 60 0 60 60 0 8 0 uvmvnodes 72 1976 0 0 36 0 36 36 0 8 0 vnodes 208 1976 0 0 104 0 104 104 0 8 0 namei 1024 6561 0 6561 1 0 1 1 0 8 1 vcpupl 1984 3 0 0 1 0 1 1 0 8 0 vmpool 528 3 0 0 1 0 1 1 0 8 0 pfiaddrpl 120 14 0 12 1 0 1 1 0 8 0 scxspl 192 7616 0 7616 1 0 1 1 0 8 1 plimitpl 152 46 0 38 1 0 1 1 0 8 0 sigapl 424 495 0 465 4 0 4 4 0 8 0 futexpl 56 6409 0 6409 1 0 1 1 0 8 1 knotepl 112 93 0 74 1 0 1 1 0 8 0 kqueuepl 144 50 0 48 1 0 1 1 0 8 0 pipelkpl 16 246 0 236 1 0 1 1 0 8 0 pipepl 120 492 0 473 2 0 2 2 0 8 1 fdescpl 432 479 0 465 2 0 2 2 0 8 0 filepl 120 3098 0 3001 4 0 4 4 0 8 1 lockfpl 104 90 0 89 1 0 1 1 0 8 0 lockfspl 48 27 0 26 1 0 1 1 0 8 0 sessionpl 112 18 0 8 1 0 1 1 0 8 0 pgrppl 48 20 0 10 1 0 1 1 0 8 0 ucredpl 96 267 0 260 1 0 1 1 0 8 0 zombiepl 144 465 0 464 1 0 1 1 0 8 0 processpl 920 495 0 464 4 0 4 4 0 8 0 procpl 624 810 0 771 4 0 4 4 0 8 1 sosppl 128 2 0 2 1 0 1 1 0 8 1 sockpl 400 693 0 673 5 1 4 4 0 8 2 mcl64k 65536 17 0 17 1 0 1 1 0 8 1 mcl16k 16384 2 0 2 1 0 1 1 0 8 1 mcl12k 12288 7 0 7 1 0 1 1 0 8 1 mcl9k 9216 2 0 2 1 0 1 1 0 8 1 mcl8k 8192 9 0 9 1 0 1 1 0 8 1 mcl4k 4096 25 0 25 2 1 1 1 0 8 1 mcl2k2 2112 2 0 2 1 0 1 1 0 8 1 mcl2k 2048 73692 0 73639 20 11 9 17 0 8 2 mtagpl 80 43 0 17 2 1 1 1 0 8 0 mbufpl 256 119511 0 119372 18 3 15 15 0 8 3 bufpl 280 4312 0 128 299 0 299 299 0 8 0 anonpl 16 62413 0 46927 81 2 79 79 0 107 15 amapchunkpl 152 2023 0 1898 8 2 6 8 0 158 0 amappl16 192 2399 0 1514 57 4 53 57 0 8 8 amappl15 184 1 0 0 1 0 1 1 0 8 0 amappl14 176 41 0 35 1 0 1 1 0 8 0 amappl13 168 33 0 30 1 0 1 1 0 8 0 amappl12 160 11 0 10 2 1 1 1 0 8 0 amappl11 152 50 0 41 1 0 1 1 0 8 0 amappl10 144 156 0 149 1 0 1 1 0 8 0 amappl9 136 484 0 482 1 0 1 1 0 8 0 amappl8 128 464 0 425 2 0 2 2 0 8 0 amappl7 120 253 0 239 1 0 1 1 0 8 0 amappl6 112 27 0 20 1 0 1 1 0 8 0 amappl5 104 435 0 424 1 0 1 1 0 8 0 amappl4 96 445 0 415 1 0 1 1 0 8 0 amappl3 88 111 0 106 1 0 1 1 0 8 0 amappl2 80 2944 0 2881 2 0 2 2 0 8 0 amappl1 72 18105 0 17689 24 15 9 17 0 8 0 amappl 80 1050 0 1009 1 0 1 1 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 9 0 4 1 0 1 1 0 8 0 uaddrrnd 24 482 0 465 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 482 0 465 1 0 1 1 0 8 0 vmmpekpl 168 7893 0 7866 2 0 2 2 0 8 0 vmmpepl 168 64276 0 62308 129 9 120 120 0 357 31 vmsppl 272 481 0 465 2 0 2 2 0 8 0 pdppl 4096 970 0 933 6 1 5 6 0 8 0 pvpl 32 189159 0 170691 181 0 181 181 0 265 31 pmappl 200 481 0 465 1 0 1 1 0 8 0 extentpl 40 53 0 36 1 0 1 1 0 8 0 phpool 112 255 0 20 7 0 7 7 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:398 panic(ffffffff823abf38) at panic+0x15c sys/kern/subr_prf.c:207 syn_cache_insert(fffffd8060087c70,ffff800000abf440) at syn_cache_insert+0x944 sys/netinet/tcp_input.c:3235 syn_cache_add(ffff80001d6787f8,ffff80001d6787a8,fffffd8006042068,28,fffffd80658d8c80,fffffd80581f6f00) at syn_cache_add+0x66b tcp_input(ffff80001d678b28,ffff80001d678b34,6,18) at tcp_input+0x37d8 sys/netinet/tcp_input.c:830 ip_deliver(ffff80001d678b28,ffff80001d678b34,6,18) at ip_deliver+0x2e3 sys/netinet/ip_input.c:668 ip6_input_if(ffff80001d678b28,ffff80001d678b34,29,0,ffff800000677800) at ip6_input_if+0x1526 ip6_ours sys/netinet6/ip6_input.c:538 [inline] ip6_input_if(ffff80001d678b28,ffff80001d678b34,29,0,ffff800000677800) at ip6_input_if+0x1526 sys/netinet6/ip6_input.c:471 ipv6_input(ffff800000677800,fffffd80581f6f00) at ipv6_input+0x48 sys/netinet6/ip6_input.c:171 if_input_local(ffff800000677800,fffffd80581f6f00,18) at if_input_local+0x121 sys/net/if.c:779 loinput(ffff800000677800,fffffd80581f6f00,0) at loinput+0x4f sys/net/if_loop.c:239 if_input_process(ffff800000677800,ffff80001d678c78) at if_input_process+0xf8 if_ih_input sys/net/if.c:908 [inline] if_input_process(ffff800000677800,ffff80001d678c78) at if_input_process+0xf8 sys/net/if.c:942 ifiq_process(ffff800000677bb8) at ifiq_process+0x80 sys/net/ifq.c:646 taskq_thread(ffff80000002b080) at taskq_thread+0x92 sys/kern/kern_task.c:438 end trace frame: 0x0, count: -13 ddb> machine ddbcpu 1 No such command ddb> trace db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:398 panic(ffffffff823abf38) at panic+0x15c sys/kern/subr_prf.c:207 syn_cache_insert(fffffd8060087c70,ffff800000abf440) at syn_cache_insert+0x944 sys/netinet/tcp_input.c:3235 syn_cache_add(ffff80001d6787f8,ffff80001d6787a8,fffffd8006042068,28,fffffd80658d8c80,fffffd80581f6f00) at syn_cache_add+0x66b tcp_input(ffff80001d678b28,ffff80001d678b34,6,18) at tcp_input+0x37d8 sys/netinet/tcp_input.c:830 ip_deliver(ffff80001d678b28,ffff80001d678b34,6,18) at ip_deliver+0x2e3 sys/netinet/ip_input.c:668 ip6_input_if(ffff80001d678b28,ffff80001d678b34,29,0,ffff800000677800) at ip6_input_if+0x1526 ip6_ours sys/netinet6/ip6_input.c:538 [inline] ip6_input_if(ffff80001d678b28,ffff80001d678b34,29,0,ffff800000677800) at ip6_input_if+0x1526 sys/netinet6/ip6_input.c:471 ipv6_input(ffff800000677800,fffffd80581f6f00) at ipv6_input+0x48 sys/netinet6/ip6_input.c:171 if_input_local(ffff800000677800,fffffd80581f6f00,18) at if_input_local+0x121 sys/net/if.c:779 loinput(ffff800000677800,fffffd80581f6f00,0) at loinput+0x4f sys/net/if_loop.c:239 if_input_process(ffff800000677800,ffff80001d678c78) at if_input_process+0xf8 if_ih_input sys/net/if.c:908 [inline] if_input_process(ffff800000677800,ffff80001d678c78) at if_input_process+0xf8 sys/net/if.c:942 ifiq_process(ffff800000677bb8) at ifiq_process+0x80 sys/net/ifq.c:646 taskq_thread(ffff80000002b080) at taskq_thread+0x92 sys/kern/kern_task.c:438 end trace frame: 0x0, count: -13