panic: syn_cache_insert: cacheoverflow: impossible Stopped at db_enter+0x18: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND * 44268 30946 0 0x14000 0x200 0 softnet db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:398 panic(ffffffff823e79fb) at panic+0x164 sys/kern/subr_prf.c:218 syn_cache_insert(fffffd8053a42e88,ffff800000b53770) at syn_cache_insert+0x944 sys/netinet/tcp_input.c:3235 syn_cache_add(ffff80001d678088,ffff80001d678038,fffffd805a228cc4,14,fffffd805da6be18,fffffd805a228c00) at syn_cache_add+0x66b tcp_input(ffff80001d678388,ffff80001d678394,6,2) at tcp_input+0x37f6 sys/netinet/tcp_input.c:830 ip_deliver(ffff80001d678388,ffff80001d678394,6,2) at ip_deliver+0x2e3 sys/netinet/ip_input.c:668 ip_ours(ffff80001d678388,ffff80001d678394,0,0) at ip_ours+0x4fe sys/netinet/ip_input.c:563 ip_input_if(ffff80001d678388,ffff80001d678394,4,0,ffff800000679000) at ip_input_if+0x571 ipv4_input(ffff800000679000,fffffd805a228c00) at ipv4_input+0x48 sys/netinet/ip_input.c:215 if_input_local(ffff800000679000,fffffd805a228c00,2) at if_input_local+0xf9 sys/net/if.c:769 loinput(ffff800000679000,fffffd805a228c00) at loinput+0x4d sys/net/if_loop.c:238 if_input_process(ffff800000679000,ffff80001d6784c8) 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: 1 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(ffffffff823e79fb) at panic+0x164 sys/kern/subr_prf.c:218 syn_cache_insert(fffffd8053a42e88,ffff800000b53770) at syn_cache_insert+0x944 sys/netinet/tcp_input.c:3235 syn_cache_add(ffff80001d678088,ffff80001d678038,fffffd805a228cc4,14,fffffd805da6be18,fffffd805a228c00) at syn_cache_add+0x66b tcp_input(ffff80001d678388,ffff80001d678394,6,2) at tcp_input+0x37f6 sys/netinet/tcp_input.c:830 ip_deliver(ffff80001d678388,ffff80001d678394,6,2) at ip_deliver+0x2e3 sys/netinet/ip_input.c:668 ip_ours(ffff80001d678388,ffff80001d678394,0,0) at ip_ours+0x4fe sys/netinet/ip_input.c:563 ip_input_if(ffff80001d678388,ffff80001d678394,4,0,ffff800000679000) at ip_input_if+0x571 ipv4_input(ffff800000679000,fffffd805a228c00) at ipv4_input+0x48 sys/netinet/ip_input.c:215 if_input_local(ffff800000679000,fffffd805a228c00,2) at if_input_local+0xf9 sys/net/if.c:769 loinput(ffff800000679000,fffffd805a228c00) at loinput+0x4d sys/net/if_loop.c:238 if_input_process(ffff800000679000,ffff80001d6784c8) 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: -14 ddb> show registers rdi 0 rsi 0x1 rbp 0xffff80001d677c00 rbx 0xffff80001d677cb0 rdx 0x8b rcx 0x2 rax 0x1 r8 0xffff80001d677bc0 r9 0xffffffff817fa6cf kprintf+0x15f r10 0x1 r11 0xfcba134c378b6974 r12 0x3000000008 r13 0xffff80001d677c10 r14 0x100 r15 0x1 rip 0xffffffff81e60e68 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff80001d677bf0 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb> show proc PROC (softnet) pid=44268 stat=onproc flags process=14000 proc=200 pri=32, usrpri=50, nice=20 forw=0xffffffffffffffff, list=0xffff80001d651c30,0xffff80001d6514f0 process=0xffff8000ffffe740 user=0xffff80001d673000, vmspace=0xffffffff82869550 estcpu=0, cpticks=0, pctcpu=0.0 user=0, sys=0, intr=0 ddb> ps PID TID PPID UID S FLAGS WAIT COMMAND 55372 520982 321 0 2 0 syz-executor.0 55372 46454 321 0 3 0x4000080 netcon2 syz-executor.0 33747 102562 98471 0 3 0x82 nanosleep syz-executor.1 64952 292414 0 0 3 0x14200 bored sosplice 33931 64906 0 0 3 0x14280 nfsidl nfsio 30822 188933 0 0 3 0x14280 nfsidl nfsio 10516 222655 0 0 3 0x14280 nfsidl nfsio 89232 490 0 0 3 0x14280 nfsidl nfsio 59704 451708 0 0 3 0x14280 nfsidl nfsio 96149 117415 0 0 3 0x14280 nfsidl nfsio 41024 429150 0 0 3 0x14280 nfsidl nfsio 58052 506919 0 0 3 0x14280 nfsidl nfsio 9648 324535 0 0 3 0x14280 nfsidl nfsio 57721 213094 0 0 3 0x14280 nfsidl nfsio 94133 442246 0 0 3 0x14280 nfsidl nfsio 77386 441020 0 0 3 0x14280 nfsidl nfsio 62400 312599 0 0 3 0x14280 nfsidl nfsio 57996 184046 0 0 3 0x14280 nfsidl nfsio 65854 513866 0 0 3 0x14280 nfsidl nfsio 48385 132365 0 0 3 0x14280 nfsidl nfsio 74776 55198 0 0 3 0x14280 nfsidl nfsio 80495 437146 0 0 3 0x14280 nfsidl nfsio 56233 43451 0 0 3 0x14280 nfsidl nfsio 59194 411056 0 0 3 0x14280 nfsidl nfsio 321 324199 98471 0 3 0x82 nanosleep syz-executor.0 98471 106321 67859 0 3 0x82 thrsleep syz-fuzzer 98471 319373 67859 0 3 0x4000082 nanosleep syz-fuzzer 98471 462816 67859 0 3 0x4000082 thrsleep syz-fuzzer 98471 126140 67859 0 3 0x4000082 thrsleep syz-fuzzer 98471 132992 67859 0 3 0x4000082 thrsleep syz-fuzzer 98471 332068 67859 0 3 0x4000082 thrsleep syz-fuzzer 98471 234015 67859 0 3 0x4000082 kqread syz-fuzzer 67859 264303 88826 0 3 0x10008a pause ksh 88826 287669 55068 0 3 0x92 select sshd 69524 182202 1 0 3 0x100083 ttyin getty 55068 112667 1 0 3 0x80 select sshd 34348 521247 47244 73 3 0x100090 kqread syslogd 47244 4655 1 0 3 0x100082 netio syslogd 57206 415204 1 77 3 0x100090 poll dhclient 51360 211912 1 0 3 0x80 poll dhclient 99434 302657 0 0 3 0x14200 bored smr 35579 395045 0 0 2 0x14200 zerothread 80943 404767 0 0 3 0x14200 aiodoned aiodoned 34882 78577 0 0 3 0x14200 syncer update 52201 104319 0 0 3 0x14200 cleaner cleaner 2050 33691 0 0 3 0x14200 reaper reaper 7297 488481 0 0 3 0x14200 pgdaemon pagedaemon 68553 379750 0 0 3 0x14200 bored crynlk 98905 120717 0 0 3 0x14200 bored crypto 91762 489754 0 0 3 0x40014200 acpi0 acpi0 *30946 44268 0 0 7 0x14200 softnet 55185 30696 0 0 3 0x14200 bored systqmp 76247 265575 0 0 3 0x14200 bored systq 10728 177172 0 0 3 0x40014200 bored softclock 32170 501925 0 0 3 0x40014200 idle0 1 85148 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 9511 6475K 6721K 78643K 11222 0 pcb 13 8K 8K 78643K 95 0 rtable 116 7K 9K 78643K 590 0 ifaddr 89 17K 17K 78643K 182 0 sysctl 2 0K 0K 78643K 2 0 counters 22 16K 16K 78643K 29 0 ioctlops 0 0K 4K 78643K 444 0 iov 0 0K 18K 78643K 582 0 mount 1 1K 1K 78643K 1 0 vnodes 1230 77K 77K 78643K 1477 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 0K 0K 78643K 2 0 sem 12 1K 1K 78643K 15 0 dirhash 9 1K 2K 78643K 12 0 ACPI 1809 195K 288K 78643K 12938 0 file desc 6 17K 25K 78643K 630 0 sigio 0 0K 0K 78643K 2 0 proc 49 38K 63K 78643K 536 0 subproc 32 2K 3K 78643K 102 0 NFS srvsock 1 0K 0K 78643K 1 0 NFS daemon 1 16K 16K 78643K 1 0 ip_moptions 0 0K 0K 78643K 43 0 in_multi 77 4K 4K 78643K 174 0 ether_multi 1 0K 0K 78643K 13 0 mrt 0 0K 0K 78643K 4 0 ISOFS mount 1 32K 32K 78643K 1 0 MSDOSFS mount 1 16K 16K 78643K 1 0 ttys 55 254K 254K 78643K 55 0 exec 0 0K 1K 78643K 281 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 146 73K 89K 78643K 2350 0 UVM aobj 12 2K 2K 78643K 12 0 memdesc 1 4K 4K 78643K 1 0 crypto data 1 1K 1K 78643K 1 0 ip6_options 0 0K 0K 78643K 72 0 NDP 13 0K 0K 78643K 35 0 temp 116 3861K 3936K 78643K 5654 0 kqueue 3 4K 10K 78643K 20 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 8 1 0 1 1 0 8 0 rtpcb 80 51 0 49 1 0 1 1 0 8 0 rtentry 112 111 0 73 2 0 2 2 0 8 0 unpcb 120 211 0 203 1 0 1 1 0 8 0 syncache 264 9 0 8 4 3 1 1 0 8 0 tcpqe 32 28 0 28 1 1 0 1 0 8 0 tcpcb 544 174 0 164 3 1 2 2 0 8 0 ipq 40 5 0 4 1 0 1 1 0 8 0 ipqe 40 16 0 15 1 0 1 1 0 8 0 inpcb 296 558 0 549 3 1 2 2 0 8 1 rttmr 72 2 0 2 1 1 0 1 0 8 0 nd6 48 23 0 17 1 0 1 1 0 8 0 pkpcb 40 6 0 6 1 1 0 1 0 8 0 ppxss 1136 1 0 1 1 1 0 1 0 8 0 pfstscr 40 2 0 1 1 0 1 1 0 8 0 pfosfp 40 1 0 0 1 0 1 1 0 8 0 pfosfpen 112 2 0 0 1 0 1 1 0 8 0 pfrktable 1344 53 0 46 1 0 1 1 0 8 0 pftag 88 5 0 4 1 0 1 1 0 8 0 pfstitem 24 2 0 0 1 0 1 1 0 8 0 pfstkey 112 4 0 2 1 0 1 1 0 8 0 pfstate 328 2 0 1 1 0 1 1 0 8 0 pfrule 1360 61 0 14 4 0 4 4 0 8 0 art_heap8 4096 1 0 0 1 0 1 1 0 8 0 art_heap4 256 447 0 265 17 5 12 13 0 8 0 art_table 32 448 0 265 2 0 2 2 0 8 0 art_node 16 104 0 74 1 0 1 1 0 8 0 sysvmsgpl 40 4 0 0 1 0 1 1 0 8 0 semupl 112 4 0 4 1 1 0 1 0 8 0 semapl 112 11 0 1 1 0 1 1 0 8 0 shmpl 112 9 0 0 1 0 1 1 0 8 0 dirhash 1024 17 0 10 3 1 2 3 0 8 0 dino2pl 256 2122 0 732 88 0 88 88 0 8 0 ffsino 240 2122 0 732 83 0 83 83 0 8 0 nchpl 144 3429 0 1839 60 0 60 60 0 8 0 uvmvnodes 72 2372 0 0 44 0 44 44 0 8 0 vnodes 208 2372 0 0 125 0 125 125 0 8 0 namei 1024 9610 0 9610 1 0 1 1 0 8 1 vcpupl 1984 7 0 0 1 0 1 1 0 8 0 vmpool 528 11 0 4 1 0 1 1 0 8 0 pfiaddrpl 120 34 0 22 1 0 1 1 0 8 0 scsiplug 64 1 0 1 1 1 0 1 0 8 0 scxspl 192 9072 0 9072 1 0 1 1 0 8 1 plimitpl 152 48 0 41 1 0 1 1 0 8 0 sigapl 424 825 0 775 6 0 6 6 0 8 0 futexpl 56 12118 0 12118 1 0 1 1 0 8 1 knotepl 112 130 0 110 1 0 1 1 0 8 0 kqueuepl 144 69 0 64 1 0 1 1 0 8 0 pipepl 272 141 0 130 2 1 1 2 0 8 0 fdescpl 432 790 0 775 2 0 2 2 0 8 0 filepl 120 4742 0 4639 4 0 4 4 0 8 0 lockfpl 104 100 0 99 1 0 1 1 0 8 0 lockfspl 48 30 0 29 1 0 1 1 0 8 0 sessionpl 112 21 0 11 1 0 1 1 0 8 0 pgrppl 48 25 0 15 1 0 1 1 0 8 0 ucredpl 96 371 0 364 1 0 1 1 0 8 0 zombiepl 144 776 0 775 1 0 1 1 0 8 0 processpl 928 825 0 775 7 0 7 7 0 8 0 procpl 624 1460 0 1403 6 1 5 5 0 8 0 sosppl 128 4 0 4 2 2 0 1 0 8 0 sockpl 400 830 0 811 3 0 3 3 0 8 1 mcl64k 65536 20 0 20 2 2 0 1 0 8 0 mcl16k 16384 4 0 4 2 1 1 1 0 8 1 mcl12k 12288 19 0 19 1 0 1 1 0 8 1 mcl9k 9216 4 0 4 2 1 1 1 0 8 1 mcl8k 8192 22 0 22 2 1 1 1 0 8 1 mcl4k 4096 78 0 78 2 1 1 1 0 8 1 mcl2k2 2112 3 0 3 2 1 1 1 0 8 1 mcl2k 2048 96186 0 96143 13 7 6 12 0 8 0 mtagpl 96 53 0 24 2 1 1 1 0 8 0 mbufpl 256 154860 0 154710 17 5 12 12 0 8 0 bufpl 280 4255 0 124 296 0 296 296 0 8 0 anonpl 16 104950 0 87706 97 22 75 88 0 107 0 amapchunkpl 152 3909 0 3701 16 7 9 13 0 158 0 amappl16 192 3858 0 2925 69 20 49 57 0 8 2 amappl15 184 168 0 166 1 0 1 1 0 8 0 amappl14 176 64 0 61 1 0 1 1 0 8 0 amappl13 168 54 0 51 1 0 1 1 0 8 0 amappl12 160 289 0 285 1 0 1 1 0 8 0 amappl11 152 125 0 115 1 0 1 1 0 8 0 amappl10 144 147 0 142 1 0 1 1 0 8 0 amappl9 136 255 0 250 1 0 1 1 0 8 0 amappl8 128 429 0 391 2 0 2 2 0 8 0 amappl7 120 256 0 243 1 0 1 1 0 8 0 amappl6 112 30 0 26 1 0 1 1 0 8 0 amappl5 104 1210 0 1196 1 0 1 1 0 8 0 amappl4 96 546 0 517 1 0 1 1 0 8 0 amappl3 88 196 0 188 1 0 1 1 0 8 0 amappl2 80 5256 0 5182 2 0 2 2 0 8 0 amappl1 72 26931 0 26499 23 14 9 17 0 8 0 amappl 80 1753 0 1689 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 11 0 0 1 0 1 1 0 8 0 uaddrrnd 24 801 0 779 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 801 0 779 1 0 1 1 0 8 0 vmmpekpl 168 8375 0 8338 2 0 2 2 0 8 0 vmmpepl 168 105275 0 103084 158 26 132 132 0 357 36 vmsppl 272 800 0 779 3 1 2 2 0 8 0 pdppl 4096 1608 0 1565 7 1 6 6 0 8 0 pvpl 32 294481 0 274574 213 23 190 204 0 265 23 pmappl 200 800 0 779 2 0 2 2 0 8 0 extentpl 40 53 0 36 1 0 1 1 0 8 0 phpool 112 261 0 30 8 1 7 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(ffffffff823e79fb) at panic+0x164 sys/kern/subr_prf.c:218 syn_cache_insert(fffffd8053a42e88,ffff800000b53770) at syn_cache_insert+0x944 sys/netinet/tcp_input.c:3235 syn_cache_add(ffff80001d678088,ffff80001d678038,fffffd805a228cc4,14,fffffd805da6be18,fffffd805a228c00) at syn_cache_add+0x66b tcp_input(ffff80001d678388,ffff80001d678394,6,2) at tcp_input+0x37f6 sys/netinet/tcp_input.c:830 ip_deliver(ffff80001d678388,ffff80001d678394,6,2) at ip_deliver+0x2e3 sys/netinet/ip_input.c:668 ip_ours(ffff80001d678388,ffff80001d678394,0,0) at ip_ours+0x4fe sys/netinet/ip_input.c:563 ip_input_if(ffff80001d678388,ffff80001d678394,4,0,ffff800000679000) at ip_input_if+0x571 ipv4_input(ffff800000679000,fffffd805a228c00) at ipv4_input+0x48 sys/netinet/ip_input.c:215 if_input_local(ffff800000679000,fffffd805a228c00,2) at if_input_local+0xf9 sys/net/if.c:769 loinput(ffff800000679000,fffffd805a228c00) at loinput+0x4d sys/net/if_loop.c:238 if_input_process(ffff800000679000,ffff80001d6784c8) 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: -14 ddb> machine ddbcpu 1 No such command ddb> trace db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:398 panic(ffffffff823e79fb) at panic+0x164 sys/kern/subr_prf.c:218 syn_cache_insert(fffffd8053a42e88,ffff800000b53770) at syn_cache_insert+0x944 sys/netinet/tcp_input.c:3235 syn_cache_add(ffff80001d678088,ffff80001d678038,fffffd805a228cc4,14,fffffd805da6be18,fffffd805a228c00) at syn_cache_add+0x66b tcp_input(ffff80001d678388,ffff80001d678394,6,2) at tcp_input+0x37f6 sys/netinet/tcp_input.c:830 ip_deliver(ffff80001d678388,ffff80001d678394,6,2) at ip_deliver+0x2e3 sys/netinet/ip_input.c:668 ip_ours(ffff80001d678388,ffff80001d678394,0,0) at ip_ours+0x4fe sys/netinet/ip_input.c:563 ip_input_if(ffff80001d678388,ffff80001d678394,4,0,ffff800000679000) at ip_input_if+0x571 ipv4_input(ffff800000679000,fffffd805a228c00) at ipv4_input+0x48 sys/netinet/ip_input.c:215 if_input_local(ffff800000679000,fffffd805a228c00,2) at if_input_local+0xf9 sys/net/if.c:769 loinput(ffff800000679000,fffffd805a228c00) at loinput+0x4d sys/net/if_loop.c:238 if_input_process(ffff800000679000,ffff80001d6784c8) 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: -14