panic: syn_cache_insert: cacheoverflow: impossible Stopped at db_enter+0x18: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND *254355 98041 0 0x14000 0x200 0 softnet db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:398 panic(ffffffff823ec403) at panic+0x164 sys/kern/subr_prf.c:218 syn_cache_insert(fffffd80533fdd70,ffff800000adfaa8) at syn_cache_insert+0x944 sys/netinet/tcp_input.c:3235 syn_cache_add(ffff80001d6787a8,ffff80001d678758,fffffd805bb77068,28,fffffd806b06aaf0,fffffd8057541f00) at syn_cache_add+0x66b tcp_input(ffff80001d678ad8,ffff80001d678ae4,6,18) at tcp_input+0x37f6 sys/netinet/tcp_input.c:830 ip_deliver(ffff80001d678ad8,ffff80001d678ae4,6,18) at ip_deliver+0x2e3 sys/netinet/ip_input.c:668 ip6_input_if(ffff80001d678ad8,ffff80001d678ae4,29,0,ffff800000679000) at ip6_input_if+0x15e3 ip6_ours sys/netinet6/ip6_input.c:538 [inline] ip6_input_if(ffff80001d678ad8,ffff80001d678ae4,29,0,ffff800000679000) at ip6_input_if+0x15e3 sys/netinet6/ip6_input.c:471 ipv6_input(ffff800000679000,fffffd8057541f00) at ipv6_input+0x48 sys/netinet6/ip6_input.c:171 if_input_local(ffff800000679000,fffffd8057541f00,18) at if_input_local+0x121 sys/net/if.c:773 loinput(ffff800000679000,fffffd8057541f00) at loinput+0x4d sys/net/if_loop.c:238 if_input_process(ffff800000679000,ffff80001d678c18) at if_input_process+0xda sys/net/if.c:832 ifiq_process(ffff8000006793c0) at ifiq_process+0x80 sys/net/ifq.c:768 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: cacheoverflow: impossible ddb> trace db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:398 panic(ffffffff823ec403) at panic+0x164 sys/kern/subr_prf.c:218 syn_cache_insert(fffffd80533fdd70,ffff800000adfaa8) at syn_cache_insert+0x944 sys/netinet/tcp_input.c:3235 syn_cache_add(ffff80001d6787a8,ffff80001d678758,fffffd805bb77068,28,fffffd806b06aaf0,fffffd8057541f00) at syn_cache_add+0x66b tcp_input(ffff80001d678ad8,ffff80001d678ae4,6,18) at tcp_input+0x37f6 sys/netinet/tcp_input.c:830 ip_deliver(ffff80001d678ad8,ffff80001d678ae4,6,18) at ip_deliver+0x2e3 sys/netinet/ip_input.c:668 ip6_input_if(ffff80001d678ad8,ffff80001d678ae4,29,0,ffff800000679000) at ip6_input_if+0x15e3 ip6_ours sys/netinet6/ip6_input.c:538 [inline] ip6_input_if(ffff80001d678ad8,ffff80001d678ae4,29,0,ffff800000679000) at ip6_input_if+0x15e3 sys/netinet6/ip6_input.c:471 ipv6_input(ffff800000679000,fffffd8057541f00) at ipv6_input+0x48 sys/netinet6/ip6_input.c:171 if_input_local(ffff800000679000,fffffd8057541f00,18) at if_input_local+0x121 sys/net/if.c:773 loinput(ffff800000679000,fffffd8057541f00) at loinput+0x4d sys/net/if_loop.c:238 if_input_process(ffff800000679000,ffff80001d678c18) at if_input_process+0xda sys/net/if.c:832 ifiq_process(ffff8000006793c0) at ifiq_process+0x80 sys/net/ifq.c:768 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 0xffff80001d678320 rbx 0xffff80001d6783d0 rdx 0x2 rcx 0 rax 0x1 r8 0xffffffff8109377f kprintf+0x15f r9 0x1 r10 0x2 r11 0xa565c54445e8bb03 r12 0x3000000008 r13 0xffff80001d678330 r14 0x100 r15 0x1 rip 0xffffffff82107068 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff80001d678310 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb> show proc PROC (softnet) pid=254355 stat=onproc flags process=14000 proc=200 pri=32, usrpri=50, nice=20 forw=0xffffffffffffffff, list=0xffff80001d6519c0,0xffff80001d651010 process=0xffff8000fffff220 user=0xffff80001d673000, vmspace=0xffffffff8282f660 estcpu=0, cpticks=0, pctcpu=0.36 user=0, sys=0, intr=0 ddb> ps PID TID PPID UID S FLAGS WAIT COMMAND 44398 451086 19123 0 2 0 syz-executor.1 44398 143974 19123 0 3 0x4000080 netcon2 syz-executor.1 77754 45192 0 0 3 0x14200 bored sosplice 19123 160627 54959 0 3 0x82 nanosleep syz-executor.1 869 87775 54959 0 3 0x82 nanosleep syz-executor.0 54959 386994 85480 0 3 0x82 kqread syz-fuzzer 54959 463571 85480 0 3 0x4000082 nanosleep syz-fuzzer 54959 98252 85480 0 3 0x4000082 thrsleep syz-fuzzer 54959 58428 85480 0 3 0x4000082 thrsleep syz-fuzzer 54959 330850 85480 0 3 0x4000082 thrsleep syz-fuzzer 54959 377199 85480 0 3 0x4000082 thrsleep syz-fuzzer 54959 331015 85480 0 3 0x4000082 thrsleep syz-fuzzer 85480 104359 5017 0 3 0x10008a pause ksh 5017 313173 96350 0 3 0x92 select sshd 97684 390106 1 0 3 0x100083 ttyin getty 96350 102450 1 0 3 0x80 select sshd 51828 231888 91836 73 3 0x100090 kqread syslogd 91836 427852 1 0 3 0x100082 netio syslogd 48027 172318 1 77 3 0x100090 poll dhclient 62523 5280 1 0 3 0x80 poll dhclient 85191 374600 0 0 3 0x14200 bored smr 11872 249458 0 0 2 0x14200 zerothread 51033 49087 0 0 3 0x14200 aiodoned aiodoned 48282 371522 0 0 3 0x14200 syncer update 10653 49921 0 0 3 0x14200 cleaner cleaner 62261 100952 0 0 3 0x14200 reaper reaper 46437 128313 0 0 3 0x14200 pgdaemon pagedaemon 77086 490776 0 0 3 0x14200 bored crynlk 2978 254529 0 0 3 0x14200 bored crypto 29712 23623 0 0 3 0x40014200 acpi0 acpi0 *98041 254355 0 0 7 0x14200 softnet 34936 465989 0 0 3 0x14200 bored systqmp 43024 246972 0 0 3 0x14200 bored systq 10761 238919 0 0 3 0x40014200 bored softclock 16724 366162 0 0 3 0x40014200 idle0 1 354510 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 9486 6338K 7045K 78643K 11497 0 pcb 13 8K 8K 78643K 33 0 rtable 108 3K 7K 78643K 355 0 ifaddr 62 12K 13K 78643K 104 0 sysctl 2 0K 0K 78643K 2 0 counters 21 16K 16K 78643K 23 0 ioctlops 0 0K 4K 78643K 69 0 iov 0 0K 32K 78643K 116 0 mount 1 1K 1K 78643K 1 0 vnodes 1222 77K 77K 78643K 1441 0 UFS quota 1 32K 32K 78643K 1 0 UFS mount 5 36K 36K 78643K 5 0 shm 2 1K 5K 78643K 5 0 VM map 2 0K 0K 78643K 2 0 sem 12 0K 0K 78643K 46 0 dirhash 12 2K 2K 78643K 12 0 ACPI 1809 195K 288K 78643K 12938 0 file desc 5 13K 25K 78643K 243 0 sigio 0 0K 0K 78643K 22 0 proc 49 38K 54K 78643K 376 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 19 0 in_multi 40 2K 2K 78643K 75 0 ether_multi 1 0K 0K 78643K 5 0 mrt 0 0K 0K 78643K 2 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 197 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 137 87K 112K 78643K 1419 0 UVM aobj 22 2K 2K 78643K 27 0 memdesc 1 4K 4K 78643K 1 0 crypto data 1 1K 1K 78643K 1 0 ip6_options 0 0K 0K 78643K 24 0 NDP 10 0K 0K 78643K 20 0 temp 102 3857K 3923K 78643K 5276 0 kqueue 3 4K 8K 78643K 12 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 6 0 0 1 0 1 1 0 8 0 rtpcb 80 39 0 37 1 0 1 1 0 8 0 rtentry 112 54 0 11 2 0 2 2 0 8 0 unpcb 120 129 0 121 1 0 1 1 0 8 0 syncache 264 5 0 4 2 1 1 1 0 8 0 tcpqe 32 314 0 314 1 1 0 1 0 8 0 tcpcb 544 140 0 126 2 0 2 2 0 8 0 ipq 40 37 0 37 1 1 0 1 0 8 0 ipqe 40 111 0 111 1 1 0 1 0 8 0 inpcb 296 280 0 271 2 0 2 2 0 8 1 rttmr 72 1 0 1 1 0 1 1 0 8 1 nd6 48 10 0 5 1 0 1 1 0 8 0 pfrktable 1344 45 0 45 1 0 1 1 0 8 1 pftag 88 10 0 10 2 1 1 1 0 8 1 pfrule 1360 16 0 10 1 0 1 1 0 8 0 art_heap8 4096 1 0 0 1 0 1 1 0 8 0 art_heap4 256 213 0 40 13 0 13 13 0 8 0 art_table 32 214 0 40 2 0 2 2 0 8 0 art_node 16 53 0 14 1 0 1 1 0 8 0 semupl 112 4 0 4 1 1 0 1 0 8 0 semapl 112 42 0 32 1 0 1 1 0 8 0 shmpl 112 24 0 6 1 0 1 1 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino2pl 256 1680 0 283 88 0 88 88 0 8 0 ffsino 240 1680 0 283 83 0 83 83 0 8 0 nchpl 144 2245 0 643 60 0 60 60 0 8 0 uvmvnodes 72 1924 0 0 35 0 35 35 0 8 0 vnodes 208 1924 0 0 102 0 102 102 0 8 0 namei 1024 5741 0 5741 1 0 1 1 0 8 1 vcpupl 1984 6 0 0 1 0 1 1 0 8 0 vmpool 528 11 0 5 1 0 1 1 0 8 0 pfiaddrpl 120 14 0 14 1 0 1 1 0 8 1 scxspl 192 6549 0 6549 1 0 1 1 0 8 1 plimitpl 152 24 0 17 1 0 1 1 0 8 0 sigapl 424 430 0 401 4 0 4 4 0 8 0 futexpl 56 4790 0 4790 1 0 1 1 0 8 1 knotepl 112 73 0 53 1 0 1 1 0 8 0 kqueuepl 144 34 0 32 1 0 1 1 0 8 0 pipepl 272 116 0 105 2 0 2 2 0 8 1 fdescpl 432 415 0 401 2 0 2 2 0 8 0 filepl 120 2385 0 2286 4 0 4 4 0 8 0 lockfpl 104 30 0 29 1 0 1 1 0 8 0 lockfspl 48 15 0 14 1 0 1 1 0 8 0 sessionpl 112 17 0 7 1 0 1 1 0 8 0 pgrppl 48 19 0 9 1 0 1 1 0 8 0 ucredpl 96 155 0 148 1 0 1 1 0 8 0 zombiepl 144 401 0 400 1 0 1 1 0 8 0 processpl 928 430 0 400 4 0 4 4 0 8 0 procpl 624 710 0 673 4 0 4 4 0 8 1 sosppl 128 5 0 5 1 1 0 1 0 8 0 sockpl 400 448 0 429 4 1 3 4 0 8 1 mcl64k 65536 23 0 23 1 0 1 1 0 8 1 mcl12k 12288 10 0 10 1 0 1 1 0 8 1 mcl9k 9216 3 0 3 1 0 1 1 0 8 1 mcl8k 8192 9 0 9 1 0 1 1 0 8 1 mcl4k 4096 29 0 29 2 1 1 1 0 8 1 mcl2k2 2112 1 0 1 1 1 0 1 0 8 0 mcl2k 2048 94158 0 94104 21 13 8 16 0 8 0 mtagpl 96 146 0 9 5 1 4 4 0 8 0 mbufpl 256 153480 0 153094 120 88 32 103 0 8 7 bufpl 280 3736 0 116 259 0 259 259 0 8 0 anonpl 16 53814 0 37201 75 7 68 72 0 107 1 amapchunkpl 152 2459 0 2283 25 4 21 21 0 158 13 amappl16 192 1941 0 1064 46 1 45 45 0 8 1 amappl15 184 3 0 1 1 0 1 1 0 8 0 amappl14 176 1 0 0 1 0 1 1 0 8 0 amappl13 168 131 0 126 1 0 1 1 0 8 0 amappl12 160 126 0 121 1 0 1 1 0 8 0 amappl11 152 48 0 39 1 0 1 1 0 8 0 amappl10 144 10 0 7 1 0 1 1 0 8 0 amappl9 136 357 0 356 1 0 1 1 0 8 0 amappl8 128 287 0 261 1 0 1 1 0 8 0 amappl7 120 111 0 99 1 0 1 1 0 8 0 amappl6 112 26 0 22 1 0 1 1 0 8 0 amappl5 104 240 0 230 1 0 1 1 0 8 0 amappl4 96 528 0 499 1 0 1 1 0 8 0 amappl3 88 234 0 222 1 0 1 1 0 8 0 amappl2 80 2506 0 2436 2 0 2 2 0 8 0 amappl1 72 18494 0 18063 23 14 9 17 0 8 0 amappl 80 949 0 892 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 26 0 5 1 0 1 1 0 8 0 uaddrrnd 24 426 0 406 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 426 0 406 1 0 1 1 0 8 0 vmmpekpl 168 6657 0 6629 2 0 2 2 0 8 0 vmmpepl 168 57440 0 55445 119 16 103 114 0 357 15 vmsppl 272 425 0 406 2 0 2 2 0 8 0 pdppl 4096 858 0 818 6 0 6 6 0 8 0 pvpl 32 173552 0 153953 172 8 164 172 0 265 4 pmappl 200 425 0 406 2 0 2 2 0 8 0 extentpl 40 53 0 36 1 0 1 1 0 8 0 phpool 112 357 0 105 11 1 10 10 0 8 1 ddb> machine ddbcpu 0 No such command ddb> trace db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:398 panic(ffffffff823ec403) at panic+0x164 sys/kern/subr_prf.c:218 syn_cache_insert(fffffd80533fdd70,ffff800000adfaa8) at syn_cache_insert+0x944 sys/netinet/tcp_input.c:3235 syn_cache_add(ffff80001d6787a8,ffff80001d678758,fffffd805bb77068,28,fffffd806b06aaf0,fffffd8057541f00) at syn_cache_add+0x66b tcp_input(ffff80001d678ad8,ffff80001d678ae4,6,18) at tcp_input+0x37f6 sys/netinet/tcp_input.c:830 ip_deliver(ffff80001d678ad8,ffff80001d678ae4,6,18) at ip_deliver+0x2e3 sys/netinet/ip_input.c:668 ip6_input_if(ffff80001d678ad8,ffff80001d678ae4,29,0,ffff800000679000) at ip6_input_if+0x15e3 ip6_ours sys/netinet6/ip6_input.c:538 [inline] ip6_input_if(ffff80001d678ad8,ffff80001d678ae4,29,0,ffff800000679000) at ip6_input_if+0x15e3 sys/netinet6/ip6_input.c:471 ipv6_input(ffff800000679000,fffffd8057541f00) at ipv6_input+0x48 sys/netinet6/ip6_input.c:171 if_input_local(ffff800000679000,fffffd8057541f00,18) at if_input_local+0x121 sys/net/if.c:773 loinput(ffff800000679000,fffffd8057541f00) at loinput+0x4d sys/net/if_loop.c:238 if_input_process(ffff800000679000,ffff80001d678c18) at if_input_process+0xda sys/net/if.c:832 ifiq_process(ffff8000006793c0) at ifiq_process+0x80 sys/net/ifq.c:768 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(ffffffff823ec403) at panic+0x164 sys/kern/subr_prf.c:218 syn_cache_insert(fffffd80533fdd70,ffff800000adfaa8) at syn_cache_insert+0x944 sys/netinet/tcp_input.c:3235 syn_cache_add(ffff80001d6787a8,ffff80001d678758,fffffd805bb77068,28,fffffd806b06aaf0,fffffd8057541f00) at syn_cache_add+0x66b tcp_input(ffff80001d678ad8,ffff80001d678ae4,6,18) at tcp_input+0x37f6 sys/netinet/tcp_input.c:830 ip_deliver(ffff80001d678ad8,ffff80001d678ae4,6,18) at ip_deliver+0x2e3 sys/netinet/ip_input.c:668 ip6_input_if(ffff80001d678ad8,ffff80001d678ae4,29,0,ffff800000679000) at ip6_input_if+0x15e3 ip6_ours sys/netinet6/ip6_input.c:538 [inline] ip6_input_if(ffff80001d678ad8,ffff80001d678ae4,29,0,ffff800000679000) at ip6_input_if+0x15e3 sys/netinet6/ip6_input.c:471 ipv6_input(ffff800000679000,fffffd8057541f00) at ipv6_input+0x48 sys/netinet6/ip6_input.c:171 if_input_local(ffff800000679000,fffffd8057541f00,18) at if_input_local+0x121 sys/net/if.c:773 loinput(ffff800000679000,fffffd8057541f00) at loinput+0x4d sys/net/if_loop.c:238 if_input_process(ffff800000679000,ffff80001d678c18) at if_input_process+0xda sys/net/if.c:832 ifiq_process(ffff8000006793c0) at ifiq_process+0x80 sys/net/ifq.c:768 taskq_thread(ffff80000002b080) at taskq_thread+0x92 sys/kern/kern_task.c:438 end trace frame: 0x0, count: -13