panic: syn_cache_insert: cacheoverflow: impossible Stopped at db_enter+0x18: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND *484691 69801 0 0x14000 0x200 0 softnet db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:398 panic(ffffffff8239c565) at panic+0x15e sys/kern/subr_prf.c:218 syn_cache_insert(fffffd805fcb5ef0,ffff800000ada6f0) at syn_cache_insert+0x924 sys/netinet/tcp_input.c:3235 syn_cache_add(ffff80001d676100,ffff80001d6760b0,fffffd8006006868,28,fffffd805da49198,fffffd805bc18200) at syn_cache_add+0x651 tcp_input(ffff80001d676428,ffff80001d676434,6,18) at tcp_input+0x367e sys/netinet/tcp_input.c:830 ip_deliver(ffff80001d676428,ffff80001d676434,6,18) at ip_deliver+0x2a3 sys/netinet/ip_input.c:604 ip6_input_if(ffff80001d676428,ffff80001d676434,29,0,ffff800000679000) at ip6_input_if+0x155f ip6_ours sys/netinet6/ip6_input.c:536 [inline] ip6_input_if(ffff80001d676428,ffff80001d676434,29,0,ffff800000679000) at ip6_input_if+0x155f sys/netinet6/ip6_input.c:469 ipv6_input(ffff800000679000,fffffd805bc18200) at ipv6_input+0x48 sys/netinet6/ip6_input.c:171 if_input_local(ffff800000679000,fffffd805bc18200,18) at if_input_local+0x11d sys/net/if.c:771 loinput(ffff800000679000,fffffd805bc18200) at loinput+0x4d sys/net/if_loop.c:238 if_input_process(ffff800000679000,ffff80001d676568) at if_input_process+0xd2 sys/net/if.c:830 ifiq_process(ffff8000006793f0) at ifiq_process+0x80 sys/net/ifq.c:768 taskq_thread(ffff80000002b080) at taskq_thread+0x8d sys/kern/kern_task.c:449 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: cacheoverflow: impossible ddb> trace db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:398 panic(ffffffff8239c565) at panic+0x15e sys/kern/subr_prf.c:218 syn_cache_insert(fffffd805fcb5ef0,ffff800000ada6f0) at syn_cache_insert+0x924 sys/netinet/tcp_input.c:3235 syn_cache_add(ffff80001d676100,ffff80001d6760b0,fffffd8006006868,28,fffffd805da49198,fffffd805bc18200) at syn_cache_add+0x651 tcp_input(ffff80001d676428,ffff80001d676434,6,18) at tcp_input+0x367e sys/netinet/tcp_input.c:830 ip_deliver(ffff80001d676428,ffff80001d676434,6,18) at ip_deliver+0x2a3 sys/netinet/ip_input.c:604 ip6_input_if(ffff80001d676428,ffff80001d676434,29,0,ffff800000679000) at ip6_input_if+0x155f ip6_ours sys/netinet6/ip6_input.c:536 [inline] ip6_input_if(ffff80001d676428,ffff80001d676434,29,0,ffff800000679000) at ip6_input_if+0x155f sys/netinet6/ip6_input.c:469 ipv6_input(ffff800000679000,fffffd805bc18200) at ipv6_input+0x48 sys/netinet6/ip6_input.c:171 if_input_local(ffff800000679000,fffffd805bc18200,18) at if_input_local+0x11d sys/net/if.c:771 loinput(ffff800000679000,fffffd805bc18200) at loinput+0x4d sys/net/if_loop.c:238 if_input_process(ffff800000679000,ffff80001d676568) at if_input_process+0xd2 sys/net/if.c:830 ifiq_process(ffff8000006793f0) at ifiq_process+0x80 sys/net/ifq.c:768 taskq_thread(ffff80000002b080) at taskq_thread+0x8d sys/kern/kern_task.c:449 end trace frame: 0x0, count: -13 ddb> show registers rdi 0 rsi 0x1 rbp 0xffff80001d675c50 rbx 0xffff80001d675c60 rdx 0x8b rcx 0x2 rax 0x1 r8 0xffff80001d675c10 r9 0xffffffff81ebe8e0 kprintf+0x140 r10 0x1 r11 0x1b8ad5c57dd93df r12 0x3000000008 r13 0xffff80001d675d00 r14 0x100 r15 0x1 rip 0xffffffff822488b8 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff80001d675c40 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb> show proc PROC (softnet) pid=484691 stat=onproc flags process=14000 proc=200 pri=32, usrpri=50, nice=20 forw=0xffffffffffffffff, list=0xffff8000ffffe9e0,0xffff8000ffffe288 process=0xffff8000ffffc760 user=0xffff80001d671000, vmspace=0xffffffff827ca5e0 estcpu=0, cpticks=0, pctcpu=0.0 user=0, sys=0, intr=0 ddb> ps PID TID PPID UID S FLAGS WAIT COMMAND 26472 63734 36533 0 2 0 syz-executor.1 26472 33329 36533 0 3 0x4000080 netcon2 syz-executor.1 46020 308269 0 0 3 0x14280 nfsidl nfsio 64220 483920 0 0 3 0x14280 nfsidl nfsio 15200 91918 0 0 3 0x14280 nfsidl nfsio 32076 448364 0 0 3 0x14280 nfsidl nfsio 66215 174392 0 0 3 0x14280 nfsidl nfsio 23529 152003 0 0 3 0x14280 nfsidl nfsio 75860 367557 0 0 3 0x14280 nfsidl nfsio 27071 8675 0 0 3 0x14280 nfsidl nfsio 86956 93631 0 0 3 0x14280 nfsidl nfsio 22449 351592 0 0 3 0x14280 nfsidl nfsio 58020 80357 0 0 3 0x14280 nfsidl nfsio 81695 84644 0 0 3 0x14280 nfsidl nfsio 16125 5791 0 0 3 0x14280 nfsidl nfsio 14526 40183 0 0 3 0x14280 nfsidl nfsio 1487 52963 0 0 3 0x14280 nfsidl nfsio 12687 296678 0 0 3 0x14280 nfsidl nfsio 60876 323950 0 0 3 0x14280 nfsidl nfsio 38095 196470 0 0 3 0x14280 nfsidl nfsio 10005 106943 0 0 3 0x14280 nfsidl nfsio 80830 493623 0 0 3 0x14280 nfsidl nfsio 36533 16728 46700 0 3 0x82 nanosleep syz-executor.1 27185 510310 0 0 3 0x14200 acct acct 64970 129356 1 0 3 0x100083 ttyin getty 6444 385248 0 0 3 0x14200 bored sosplice 16614 203952 46700 0 3 0x82 piperd syz-executor.0 46700 318366 21113 0 3 0x82 thrsleep syz-fuzzer 46700 279844 21113 0 3 0x4000082 nanosleep syz-fuzzer 46700 88369 21113 0 2 0x4000002 syz-fuzzer 46700 331092 21113 0 3 0x4000082 thrsleep syz-fuzzer 46700 336283 21113 0 3 0x4000082 thrsleep syz-fuzzer 46700 20843 21113 0 3 0x4000082 thrsleep syz-fuzzer 46700 377079 21113 0 3 0x4000082 thrsleep syz-fuzzer 21113 478703 39700 0 3 0x10008a pause ksh 39700 169295 46589 0 3 0x92 select sshd 46589 438539 1 0 3 0x80 select sshd 92909 93312 29358 73 3 0x100090 kqread syslogd 29358 1094 1 0 3 0x100082 netio syslogd 73585 29818 1 77 3 0x100090 poll dhclient 53262 238314 1 0 3 0x80 poll dhclient 71104 295062 0 0 3 0x14200 bored smr 76252 173173 0 0 2 0x14200 zerothread 40560 455877 0 0 3 0x14200 aiodoned aiodoned 58133 173675 0 0 3 0x14200 syncer update 2184 517850 0 0 3 0x14200 cleaner cleaner 6513 337942 0 0 3 0x14200 reaper reaper 4352 183963 0 0 3 0x14200 pgdaemon pagedaemon 30939 430669 0 0 3 0x14200 bored crynlk 28410 356691 0 0 3 0x14200 bored crypto 26812 364168 0 0 3 0x40014200 acpi0 acpi0 *69801 484691 0 0 7 0x14200 softnet 50473 14772 0 0 3 0x14200 bored systqmp 75046 129599 0 0 3 0x14200 bored systq 36741 384775 0 0 3 0x40014200 bored softclock 716 232099 0 0 3 0x40014200 idle0 1 314242 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 9528 6359K 6596K 78643K 11536 0 pcb 13 8K 8K 78643K 235 0 rtable 102 14K 18K 78643K 767 0 ifaddr 91 17K 17K 78643K 243 0 sysctl 3 1K 1K 78643K 3 0 counters 21 16K 16K 78643K 38 0 ioctlops 0 0K 4K 78643K 474 0 iov 0 0K 16K 78643K 150 0 mount 1 1K 1K 78643K 1 0 vnodes 1224 77K 77K 78643K 2039 0 UFS quota 1 32K 32K 78643K 1 0 UFS mount 5 36K 36K 78643K 5 0 shm 2 1K 5K 78643K 12 0 VM map 2 0K 0K 78643K 2 0 sem 12 1K 1K 78643K 18 0 dirhash 9 1K 2K 78643K 12 0 ACPI 1809 195K 288K 78643K 12938 0 file desc 5 13K 25K 78643K 2106 0 sigio 0 0K 0K 78643K 91 0 proc 51 38K 55K 78643K 595 0 subproc 32 2K 2K 78643K 68 0 NFS srvsock 1 0K 0K 78643K 1 0 NFS daemon 1 16K 16K 78643K 1 0 ip_moptions 0 0K 0K 78643K 126 0 in_multi 26 1K 2K 78643K 193 0 ether_multi 1 0K 0K 78643K 39 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 2K 78643K 506 0 pfkey data 0 0K 0K 78643K 2 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 162 154K 163K 78643K 5319 0 UVM aobj 69 7K 7K 78643K 71 0 memdesc 1 4K 4K 78643K 1 0 crypto data 1 1K 1K 78643K 1 0 ip6_options 2 0K 0K 78643K 198 0 NDP 16 0K 0K 78643K 46 0 temp 155 3971K 4035K 78643K 28995 0 kqueue 3 4K 17K 78643K 103 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 16 0 9 1 0 1 1 0 8 0 rtpcb 88 91 0 89 1 0 1 1 0 8 0 rtentry 112 105 0 74 2 0 2 2 0 8 0 unpcb 120 2914 0 2903 1 0 1 1 0 8 0 syncache 272 17 0 16 6 5 1 1 0 8 0 tcpqe 32 50 0 50 2 2 0 1 0 8 0 tcpcb 592 469 0 462 5 4 1 3 0 8 0 ipq 40 7 0 7 5 5 0 1 0 8 0 ipqe 40 61 0 61 5 5 0 1 0 8 0 inpcb 296 1232 0 1221 15 13 2 2 0 8 1 nd6 48 20 0 14 1 0 1 1 0 8 0 pkpcb 40 14 0 14 5 5 0 1 0 8 0 ppxss 1136 6 0 6 4 4 0 1 0 8 0 pfrktable 1344 112 0 105 4 3 1 2 0 8 0 pftag 88 30 0 28 1 0 1 1 0 8 0 pfstitem 24 2 0 0 1 0 1 1 0 8 0 pfstkey 112 2 0 0 1 0 1 1 0 8 0 pfstate 328 1 0 0 1 0 1 1 0 8 0 pfrule 1360 33 0 27 1 0 1 1 0 8 0 art_heap8 4096 1 0 0 1 0 1 1 0 8 0 art_heap4 256 495 0 325 19 8 11 13 0 8 0 art_table 32 496 0 325 2 0 2 2 0 8 0 art_node 16 104 0 76 1 0 1 1 0 8 0 sysvmsgpl 40 13 0 3 1 0 1 1 0 8 0 semupl 112 2 0 2 1 1 0 1 0 8 0 semapl 112 10 0 0 1 0 1 1 0 8 0 shmpl 112 68 0 2 2 0 2 2 0 8 0 dirhash 1024 17 0 10 3 1 2 3 0 8 0 dino2pl 256 4761 0 3364 88 0 88 88 0 8 0 ffsino 240 4761 0 3364 83 0 83 83 0 8 0 nchpl 144 8825 0 7253 60 0 60 60 0 8 0 uvmvnodes 72 5033 0 0 92 0 92 92 0 8 0 vnodes 208 5033 0 0 265 0 265 265 0 8 0 namei 1024 23338 0 23338 6 5 1 1 0 8 1 vcpupl 1984 15 0 0 2 0 2 2 0 8 0 vmpool 528 30 0 15 6 5 1 2 0 8 0 pfiaddrpl 120 36 0 30 1 0 1 1 0 8 0 scsiplug 72 1 0 1 1 1 0 1 0 8 0 scxspl 200 22839 0 22839 9 8 1 1 0 8 1 plimitpl 152 91 0 84 1 0 1 1 0 8 0 sigapl 424 2310 0 2260 6 0 6 6 0 8 0 futexpl 56 39959 0 39959 6 5 1 1 0 8 1 knotepl 112 211 0 191 1 0 1 1 0 8 0 kqueuepl 152 244 0 237 1 0 1 1 0 8 0 pipepl 272 380 0 369 4 2 2 2 0 8 0 fdescpl 432 2274 0 2260 2 0 2 2 0 8 0 filepl 120 15166 0 15067 6 2 4 4 0 8 0 lockfpl 104 1473 0 1472 1 0 1 1 0 8 0 lockfspl 48 455 0 454 1 0 1 1 0 8 0 sessionpl 120 21 0 11 1 0 1 1 0 8 0 pgrppl 48 111 0 101 1 0 1 1 0 8 0 ucredpl 96 1052 0 1045 1 0 1 1 0 8 0 zombiepl 144 2260 0 2260 3 2 1 1 0 8 1 processpl 944 2310 0 2260 7 0 7 7 0 8 0 procpl 632 4705 0 4648 7 2 5 6 0 8 0 sosppl 144 11 0 11 5 5 0 1 0 8 0 sockpl 400 4256 0 4232 23 19 4 4 0 8 1 mcl64k 65536 316 0 316 52 51 1 33 0 8 1 mcl16k 16384 4 0 4 4 4 0 1 0 8 0 mcl12k 12288 59 0 59 19 19 0 1 0 8 0 mcl9k 9216 21 0 21 18 18 0 1 0 8 0 mcl8k 8192 98 0 98 21 20 1 1 0 8 1 mcl4k 4096 175 0 175 20 19 1 1 0 8 1 mcl2k2 2112 17 0 17 12 11 1 1 0 8 1 mcl2k 2048 92563 0 92514 18 11 7 13 0 8 0 mtagpl 96 60 0 48 3 2 1 2 0 8 0 mbufpl 256 158933 0 158810 47 36 11 23 0 8 0 bufpl 280 7911 0 2537 384 0 384 384 0 8 0 anonpl 16 203298 0 185182 136 61 75 90 0 107 0 amapchunkpl 152 9191 0 8987 45 36 9 22 0 158 0 amappl16 192 8801 0 7825 98 49 49 61 0 8 0 amappl15 184 502 0 501 1 0 1 1 0 8 0 amappl14 176 1207 0 1200 1 0 1 1 0 8 0 amappl13 168 139 0 137 1 0 1 1 0 8 0 amappl12 160 10 0 7 2 1 1 1 0 8 0 amappl11 152 53 0 44 1 0 1 1 0 8 0 amappl10 144 6 0 3 1 0 1 1 0 8 0 amappl9 136 357 0 356 3 2 1 1 0 8 0 amappl8 128 194 0 130 3 0 3 3 0 8 0 amappl7 120 248 0 243 1 0 1 1 0 8 0 amappl6 112 125 0 109 1 0 1 1 0 8 0 amappl5 104 2288 0 2276 1 0 1 1 0 8 0 amappl4 96 399 0 367 1 0 1 1 0 8 0 amappl3 88 1428 0 1419 1 0 1 1 0 8 0 amappl2 80 15783 0 15713 3 1 2 3 0 8 0 amappl1 72 63051 0 62616 23 13 10 18 0 8 0 amappl 80 4968 0 4901 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 70 0 2 2 0 2 2 0 8 0 uaddrrnd 24 2304 0 2275 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 2304 0 2275 1 0 1 1 0 8 0 vmmpekpl 168 15665 0 15633 2 0 2 2 0 8 0 vmmpepl 168 277775 0 275600 231 135 96 134 0 357 0 vmsppl 272 2303 0 2275 3 1 2 2 0 8 0 pdppl 4096 4614 0 4565 10 3 7 7 0 8 0 pvpl 32 574820 0 553804 316 138 178 208 0 265 5 pmappl 200 2303 0 2275 3 1 2 2 0 8 0 extentpl 40 53 0 36 1 0 1 1 0 8 0 phpool 112 411 0 187 8 0 8 8 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(ffffffff8239c565) at panic+0x15e sys/kern/subr_prf.c:218 syn_cache_insert(fffffd805fcb5ef0,ffff800000ada6f0) at syn_cache_insert+0x924 sys/netinet/tcp_input.c:3235 syn_cache_add(ffff80001d676100,ffff80001d6760b0,fffffd8006006868,28,fffffd805da49198,fffffd805bc18200) at syn_cache_add+0x651 tcp_input(ffff80001d676428,ffff80001d676434,6,18) at tcp_input+0x367e sys/netinet/tcp_input.c:830 ip_deliver(ffff80001d676428,ffff80001d676434,6,18) at ip_deliver+0x2a3 sys/netinet/ip_input.c:604 ip6_input_if(ffff80001d676428,ffff80001d676434,29,0,ffff800000679000) at ip6_input_if+0x155f ip6_ours sys/netinet6/ip6_input.c:536 [inline] ip6_input_if(ffff80001d676428,ffff80001d676434,29,0,ffff800000679000) at ip6_input_if+0x155f sys/netinet6/ip6_input.c:469 ipv6_input(ffff800000679000,fffffd805bc18200) at ipv6_input+0x48 sys/netinet6/ip6_input.c:171 if_input_local(ffff800000679000,fffffd805bc18200,18) at if_input_local+0x11d sys/net/if.c:771 loinput(ffff800000679000,fffffd805bc18200) at loinput+0x4d sys/net/if_loop.c:238 if_input_process(ffff800000679000,ffff80001d676568) at if_input_process+0xd2 sys/net/if.c:830 ifiq_process(ffff8000006793f0) at ifiq_process+0x80 sys/net/ifq.c:768 taskq_thread(ffff80000002b080) at taskq_thread+0x8d sys/kern/kern_task.c:449 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(ffffffff8239c565) at panic+0x15e sys/kern/subr_prf.c:218 syn_cache_insert(fffffd805fcb5ef0,ffff800000ada6f0) at syn_cache_insert+0x924 sys/netinet/tcp_input.c:3235 syn_cache_add(ffff80001d676100,ffff80001d6760b0,fffffd8006006868,28,fffffd805da49198,fffffd805bc18200) at syn_cache_add+0x651 tcp_input(ffff80001d676428,ffff80001d676434,6,18) at tcp_input+0x367e sys/netinet/tcp_input.c:830 ip_deliver(ffff80001d676428,ffff80001d676434,6,18) at ip_deliver+0x2a3 sys/netinet/ip_input.c:604 ip6_input_if(ffff80001d676428,ffff80001d676434,29,0,ffff800000679000) at ip6_input_if+0x155f ip6_ours sys/netinet6/ip6_input.c:536 [inline] ip6_input_if(ffff80001d676428,ffff80001d676434,29,0,ffff800000679000) at ip6_input_if+0x155f sys/netinet6/ip6_input.c:469 ipv6_input(ffff800000679000,fffffd805bc18200) at ipv6_input+0x48 sys/netinet6/ip6_input.c:171 if_input_local(ffff800000679000,fffffd805bc18200,18) at if_input_local+0x11d sys/net/if.c:771 loinput(ffff800000679000,fffffd805bc18200) at loinput+0x4d sys/net/if_loop.c:238 if_input_process(ffff800000679000,ffff80001d676568) at if_input_process+0xd2 sys/net/if.c:830 ifiq_process(ffff8000006793f0) at ifiq_process+0x80 sys/net/ifq.c:768 taskq_thread(ffff80000002b080) at taskq_thread+0x8d sys/kern/kern_task.c:449 end trace frame: 0x0, count: -13