panic: syn_cache_insert: cacheoverflow: impossible Stopped at db_enter+0x18: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND *235228 55453 0 0x14000 0x200 0 softnet db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:398 panic(ffffffff821dfb20) at panic+0x15c sys/kern/subr_prf.c:207 syn_cache_insert(fffffd8053ce6e78,ffff8000009f4220) at syn_cache_insert+0x944 sys/netinet/tcp_input.c:3235 syn_cache_add(ffff80001d6f8458,ffff80001d6f8408,fffffd805e49cac4,14,fffffd805eeed320,fffffd805e49ca00) at syn_cache_add+0x66b tcp_input(ffff80001d6f8758,ffff80001d6f8764,6,2) at tcp_input+0x37d8 sys/netinet/tcp_input.c:830 ip_deliver(ffff80001d6f8758,ffff80001d6f8764,6,2) at ip_deliver+0x2e3 sys/netinet/ip_input.c:668 ip_ours(ffff80001d6f8758,ffff80001d6f8764,2,0) at ip_ours+0x4fe sys/netinet/ip_input.c:563 ip_input_if(ffff80001d6f8758,ffff80001d6f8764,4,0,ffff800000677800) at ip_input_if+0x571 ipv4_input(ffff800000677800,fffffd805e49ca00) at ipv4_input+0x48 sys/netinet/ip_input.c:215 if_input_local(ffff800000677800,fffffd805e49ca00,2) at if_input_local+0xf9 sys/net/if.c:775 loinput(ffff800000677800,fffffd805e49ca00,0) at loinput+0x4f sys/net/if_loop.c:239 if_input_process(ffff800000677800,ffff80001d6f88a8) at if_input_process+0xf8 if_ih_input sys/net/if.c:908 [inline] if_input_process(ffff800000677800,ffff80001d6f88a8) at if_input_process+0xf8 sys/net/if.c:942 ifiq_process(ffff800000677bb8) at ifiq_process+0x80 sys/net/ifq.c:646 taskq_thread(ffff8000000290c0) at taskq_thread+0x52 sys/kern/kern_task.c:370 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(ffffffff821dfb20) at panic+0x15c sys/kern/subr_prf.c:207 syn_cache_insert(fffffd8053ce6e78,ffff8000009f4220) at syn_cache_insert+0x944 sys/netinet/tcp_input.c:3235 syn_cache_add(ffff80001d6f8458,ffff80001d6f8408,fffffd805e49cac4,14,fffffd805eeed320,fffffd805e49ca00) at syn_cache_add+0x66b tcp_input(ffff80001d6f8758,ffff80001d6f8764,6,2) at tcp_input+0x37d8 sys/netinet/tcp_input.c:830 ip_deliver(ffff80001d6f8758,ffff80001d6f8764,6,2) at ip_deliver+0x2e3 sys/netinet/ip_input.c:668 ip_ours(ffff80001d6f8758,ffff80001d6f8764,2,0) at ip_ours+0x4fe sys/netinet/ip_input.c:563 ip_input_if(ffff80001d6f8758,ffff80001d6f8764,4,0,ffff800000677800) at ip_input_if+0x571 ipv4_input(ffff800000677800,fffffd805e49ca00) at ipv4_input+0x48 sys/netinet/ip_input.c:215 if_input_local(ffff800000677800,fffffd805e49ca00,2) at if_input_local+0xf9 sys/net/if.c:775 loinput(ffff800000677800,fffffd805e49ca00,0) at loinput+0x4f sys/net/if_loop.c:239 if_input_process(ffff800000677800,ffff80001d6f88a8) at if_input_process+0xf8 if_ih_input sys/net/if.c:908 [inline] if_input_process(ffff800000677800,ffff80001d6f88a8) at if_input_process+0xf8 sys/net/if.c:942 ifiq_process(ffff800000677bb8) at ifiq_process+0x80 sys/net/ifq.c:646 taskq_thread(ffff8000000290c0) at taskq_thread+0x52 sys/kern/kern_task.c:370 end trace frame: 0x0, count: -14 ddb> show registers rdi 0 rsi 0x1 rbp 0xffff80001d6f7fd0 rbx 0xffff80001d6f8080 rdx 0x2 rcx 0 rax 0x1 r8 0xffffffff8182317f kprintf+0x15f r9 0x1 r10 0x2 r11 0xfae5f1ccdec62511 r12 0x3000000008 r13 0xffff80001d6f7fe0 r14 0x100 r15 0x1 rip 0xffffffff8186b358 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff80001d6f7fc0 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb> show proc PROC (softnet) pid=235228 stat=onproc flags process=14000 proc=200 pri=32, usrpri=50, nice=20 forw=0xffffffffffffffff, list=0xffff80001d6d2380,0xffff80001d6d1eb0 process=0xffff8000ffffeac8 user=0xffff80001d6f3000, vmspace=0xffffffff825e1230 estcpu=0, cpticks=0, pctcpu=0.7 user=0, sys=0, intr=0 ddb> ps PID TID PPID UID S FLAGS WAIT COMMAND 82776 312030 2691 0 2 0 syz-executor.0 82776 122936 2691 0 3 0x4000080 netcon2 syz-executor.0 29995 462894 3349 0 2 0x10 syz-executor.1 29995 353931 3349 0 3 0x4000090 fsleep syz-executor.1 83018 107564 0 0 3 0x14200 bored sosplice 2691 125752 68875 0 3 0x82 nanosleep syz-executor.0 3349 348869 68875 0 3 0x82 nanosleep syz-executor.1 68875 394769 83825 0 3 0x82 thrsleep syz-fuzzer 68875 490311 83825 0 3 0x4000082 thrsleep syz-fuzzer 68875 228722 83825 0 3 0x4000082 thrsleep syz-fuzzer 68875 274294 83825 0 3 0x4000082 thrsleep syz-fuzzer 68875 413032 83825 0 3 0x4000082 thrsleep syz-fuzzer 68875 398838 83825 0 3 0x4000082 kqread syz-fuzzer 68875 393413 83825 0 3 0x4000082 thrsleep syz-fuzzer 83825 433570 18832 0 3 0x10008a pause ksh 18832 396303 84815 0 3 0x92 select sshd 91235 406496 1 0 3 0x100083 ttyin getty 84815 292037 1 0 3 0x80 select sshd 24971 425459 55542 73 3 0x100090 kqread syslogd 55542 228318 1 0 3 0x100082 netio syslogd 879 14280 1 77 3 0x100090 poll dhclient 323 47820 1 0 3 0x80 poll dhclient 4533 44717 0 0 3 0x14200 bored smr 63891 239872 0 0 2 0x14200 zerothread 88237 54261 0 0 3 0x14200 aiodoned aiodoned 5390 192225 0 0 3 0x14200 syncer update 51947 91277 0 0 3 0x14200 cleaner cleaner 63460 451139 0 0 3 0x14200 reaper reaper 66570 44428 0 0 3 0x14200 pgdaemon pagedaemon 2923 169861 0 0 3 0x14200 bored crynlk 51674 393696 0 0 3 0x14200 bored crypto 39375 367579 0 0 3 0x40014200 acpi0 acpi0 *55453 235228 0 0 7 0x14200 softnet 36370 420029 0 0 3 0x14200 bored systqmp 11097 198723 0 0 3 0x14200 bored systq 4871 327363 0 0 3 0x40014200 bored softclock 82562 10024 0 0 3 0x40014200 idle0 1 423878 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 9515 6356K 6732K 78643K 11518 0 pcb 13 8K 8K 78643K 115 0 rtable 122 14K 18K 78643K 499 0 ifaddr 91 18K 19K 78643K 205 0 counters 21 16K 16K 78643K 26 0 ioctlops 0 0K 4K 78643K 91 0 iov 0 0K 14K 78643K 88 0 mount 1 1K 1K 78643K 1 0 vnodes 1224 77K 77K 78643K 1498 0 UFS quota 1 32K 32K 78643K 1 0 UFS mount 5 36K 36K 78643K 5 0 shm 3 5K 5K 78643K 6 0 VM map 2 0K 0K 78643K 2 0 sem 12 0K 0K 78643K 95 0 dirhash 12 2K 2K 78643K 12 0 ACPI 1809 195K 288K 78643K 12938 0 file desc 6 17K 25K 78643K 505 0 sigio 0 0K 0K 78643K 34 0 proc 49 38K 63K 78643K 409 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 1266 0 in_multi 59 3K 3K 78643K 135 0 ether_multi 1 0K 0K 78643K 18 0 mrt 0 0K 0K 78643K 7 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 213 0 pfkey data 0 0K 1K 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 136 72K 72K 78643K 1987 0 UVM aobj 13 2K 2K 78643K 19 0 memdesc 1 4K 4K 78643K 1 0 crypto data 1 1K 1K 78643K 1 0 ip6_options 0 0K 0K 78643K 96 0 NDP 13 0K 0K 78643K 22 0 temp 111 3041K 3105K 78643K 11111 0 kqueue 3 4K 8K 78643K 44 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 7 0 1 1 0 1 1 0 8 0 rtpcb 80 39 0 37 1 0 1 1 0 8 0 rtentry 112 53 0 8 2 0 2 2 0 8 0 unpcb 120 237 0 229 1 0 1 1 0 8 0 syncache 264 11 0 10 2 1 1 1 0 8 0 tcpqe 32 42 0 42 2 2 0 1 0 8 0 tcpcb 544 1379 0 1373 3 1 2 2 0 8 1 inpcb 280 1737 0 1728 2 0 2 2 0 8 1 rttmr 72 3 0 3 2 2 0 1 0 8 0 nd6 48 7 0 1 1 0 1 1 0 8 0 pkpcb 40 2 0 2 1 1 0 1 0 8 0 swfcl 56 2 0 0 1 0 1 1 0 8 0 pfstscr 40 6 0 3 1 0 1 1 0 8 0 pfrktable 1344 107 0 102 3 1 2 2 0 8 1 pftag 88 26 0 18 2 1 1 1 0 8 0 pfstitem 24 4 0 0 1 0 1 1 0 8 0 pfstkey 112 8 0 4 1 0 1 1 0 8 0 pfstate 328 4 0 2 1 0 1 1 0 8 0 pfrule 1360 33 0 22 2 0 2 2 0 8 1 art_heap8 4096 2 0 0 2 0 2 2 0 8 0 art_heap4 256 213 0 17 13 0 13 13 0 8 0 art_table 32 215 0 17 2 0 2 2 0 8 0 art_node 16 52 0 11 1 0 1 1 0 8 0 sysvmsgpl 40 8 0 4 1 0 1 1 0 8 0 semapl 112 91 0 81 1 0 1 1 0 8 0 shmpl 112 17 0 6 1 0 1 1 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino2pl 256 2074 0 677 88 0 88 88 0 8 0 ffsino 240 2074 0 677 83 0 83 83 0 8 0 nchpl 144 2936 0 1343 60 0 60 60 0 8 0 uvmvnodes 72 2319 0 0 43 0 43 43 0 8 0 vnodes 208 2319 0 0 123 0 123 123 0 8 0 namei 1024 7915 0 7915 1 0 1 1 0 8 1 vcpupl 1984 6 0 0 1 0 1 1 0 8 0 vmpool 528 8 0 2 1 0 1 1 0 8 0 pfiaddrpl 120 32 0 30 2 1 1 1 0 8 0 scxspl 192 8583 0 8583 1 0 1 1 0 8 1 plimitpl 152 50 0 43 1 0 1 1 0 8 0 sigapl 424 692 0 662 4 0 4 4 0 8 0 futexpl 56 12699 0 12698 1 0 1 1 0 8 0 knotepl 112 114 0 95 1 0 1 1 0 8 0 kqueuepl 144 70 0 68 1 0 1 1 0 8 0 pipelkpl 16 150 0 140 1 0 1 1 0 8 0 pipepl 120 300 0 281 1 0 1 1 0 8 0 fdescpl 432 677 0 662 2 0 2 2 0 8 0 filepl 120 4920 0 4822 4 0 4 4 0 8 1 lockfpl 104 90 0 89 1 0 1 1 0 8 0 lockfspl 48 35 0 34 1 0 1 1 0 8 0 sessionpl 112 17 0 7 1 0 1 1 0 8 0 pgrppl 48 25 0 15 1 0 1 1 0 8 0 ucredpl 96 429 0 421 1 0 1 1 0 8 0 zombiepl 144 662 0 662 1 0 1 1 0 8 1 processpl 920 692 0 662 4 0 4 4 0 8 0 procpl 624 1266 0 1228 4 0 4 4 0 8 1 sosppl 128 5 0 5 1 0 1 1 0 8 1 sockpl 400 2016 0 1997 4 0 4 4 0 8 2 mcl64k 65536 53 0 49 1 0 1 1 0 8 0 mcl16k 16384 4 0 4 1 0 1 1 0 8 1 mcl12k 12288 22 0 22 1 0 1 1 0 8 1 mcl9k 9216 7 0 7 2 1 1 1 0 8 1 mcl8k 8192 12 0 12 2 1 1 1 0 8 1 mcl4k 4096 51 0 51 2 1 1 1 0 8 1 mcl2k2 2112 1 0 1 1 0 1 1 0 8 1 mcl2k 2048 75266 0 75219 17 10 7 14 0 8 0 mtagpl 80 88 0 5 3 1 2 2 0 8 0 mbufpl 256 124013 0 123454 42 6 36 36 0 8 0 bufpl 280 5749 0 389 383 0 383 383 0 8 0 anonpl 16 74472 0 58642 81 11 70 79 0 107 5 amapchunkpl 152 4124 0 3993 21 13 8 19 0 158 2 amappl16 192 3287 0 2412 45 0 45 45 0 8 1 amappl15 184 1 0 0 1 0 1 1 0 8 0 amappl14 176 26 0 20 1 0 1 1 0 8 0 amappl13 168 35 0 31 1 0 1 1 0 8 0 amappl12 160 256 0 252 1 0 1 1 0 8 0 amappl11 152 57 0 46 1 0 1 1 0 8 0 amappl10 144 242 0 235 1 0 1 1 0 8 0 amappl9 136 371 0 369 1 0 1 1 0 8 0 amappl8 128 335 0 292 2 0 2 2 0 8 0 amappl7 120 333 0 320 1 0 1 1 0 8 0 amappl6 112 26 0 22 1 0 1 1 0 8 0 amappl5 104 859 0 846 1 0 1 1 0 8 0 amappl4 96 425 0 397 1 0 1 1 0 8 0 amappl3 88 127 0 122 1 0 1 1 0 8 0 amappl2 80 4601 0 4524 2 0 2 2 0 8 0 amappl1 72 21140 0 20706 24 15 9 17 0 8 0 amappl 80 1497 0 1452 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 18 0 6 1 0 1 1 0 8 0 uaddrrnd 24 685 0 664 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 685 0 664 1 0 1 1 0 8 0 vmmpekpl 168 7900 0 7870 2 0 2 2 0 8 0 vmmpepl 168 85072 0 82981 112 20 92 105 0 357 1 vmsppl 272 684 0 664 2 0 2 2 0 8 0 pdppl 4096 1376 0 1334 6 0 6 6 0 8 0 pvpl 32 261904 0 242955 262 9 253 262 0 265 100 pmappl 200 684 0 664 2 0 2 2 0 8 0 extentpl 40 53 0 36 1 0 1 1 0 8 0 phpool 112 278 0 21 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(ffffffff821dfb20) at panic+0x15c sys/kern/subr_prf.c:207 syn_cache_insert(fffffd8053ce6e78,ffff8000009f4220) at syn_cache_insert+0x944 sys/netinet/tcp_input.c:3235 syn_cache_add(ffff80001d6f8458,ffff80001d6f8408,fffffd805e49cac4,14,fffffd805eeed320,fffffd805e49ca00) at syn_cache_add+0x66b tcp_input(ffff80001d6f8758,ffff80001d6f8764,6,2) at tcp_input+0x37d8 sys/netinet/tcp_input.c:830 ip_deliver(ffff80001d6f8758,ffff80001d6f8764,6,2) at ip_deliver+0x2e3 sys/netinet/ip_input.c:668 ip_ours(ffff80001d6f8758,ffff80001d6f8764,2,0) at ip_ours+0x4fe sys/netinet/ip_input.c:563 ip_input_if(ffff80001d6f8758,ffff80001d6f8764,4,0,ffff800000677800) at ip_input_if+0x571 ipv4_input(ffff800000677800,fffffd805e49ca00) at ipv4_input+0x48 sys/netinet/ip_input.c:215 if_input_local(ffff800000677800,fffffd805e49ca00,2) at if_input_local+0xf9 sys/net/if.c:775 loinput(ffff800000677800,fffffd805e49ca00,0) at loinput+0x4f sys/net/if_loop.c:239 if_input_process(ffff800000677800,ffff80001d6f88a8) at if_input_process+0xf8 if_ih_input sys/net/if.c:908 [inline] if_input_process(ffff800000677800,ffff80001d6f88a8) at if_input_process+0xf8 sys/net/if.c:942 ifiq_process(ffff800000677bb8) at ifiq_process+0x80 sys/net/ifq.c:646 taskq_thread(ffff8000000290c0) at taskq_thread+0x52 sys/kern/kern_task.c:370 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(ffffffff821dfb20) at panic+0x15c sys/kern/subr_prf.c:207 syn_cache_insert(fffffd8053ce6e78,ffff8000009f4220) at syn_cache_insert+0x944 sys/netinet/tcp_input.c:3235 syn_cache_add(ffff80001d6f8458,ffff80001d6f8408,fffffd805e49cac4,14,fffffd805eeed320,fffffd805e49ca00) at syn_cache_add+0x66b tcp_input(ffff80001d6f8758,ffff80001d6f8764,6,2) at tcp_input+0x37d8 sys/netinet/tcp_input.c:830 ip_deliver(ffff80001d6f8758,ffff80001d6f8764,6,2) at ip_deliver+0x2e3 sys/netinet/ip_input.c:668 ip_ours(ffff80001d6f8758,ffff80001d6f8764,2,0) at ip_ours+0x4fe sys/netinet/ip_input.c:563 ip_input_if(ffff80001d6f8758,ffff80001d6f8764,4,0,ffff800000677800) at ip_input_if+0x571 ipv4_input(ffff800000677800,fffffd805e49ca00) at ipv4_input+0x48 sys/netinet/ip_input.c:215 if_input_local(ffff800000677800,fffffd805e49ca00,2) at if_input_local+0xf9 sys/net/if.c:775 loinput(ffff800000677800,fffffd805e49ca00,0) at loinput+0x4f sys/net/if_loop.c:239 if_input_process(ffff800000677800,ffff80001d6f88a8) at if_input_process+0xf8 if_ih_input sys/net/if.c:908 [inline] if_input_process(ffff800000677800,ffff80001d6f88a8) at if_input_process+0xf8 sys/net/if.c:942 ifiq_process(ffff800000677bb8) at ifiq_process+0x80 sys/net/ifq.c:646 taskq_thread(ffff8000000290c0) at taskq_thread+0x52 sys/kern/kern_task.c:370 end trace frame: 0x0, count: -14