panic: syn_cache_insert: cacheoverflow: impossible Stopped at db_enter+0x18: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND *212296 19018 0 0x14000 0x200 0 softnet db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:398 panic(ffffffff823d8c2d) at panic+0x15c sys/kern/subr_prf.c:207 syn_cache_insert(fffffd8053899e80,ffff800000ac1000) at syn_cache_insert+0x944 sys/netinet/tcp_input.c:3235 syn_cache_add(ffff80001d678718,ffff80001d6786c8,fffffd80591727c4,14,fffffd805da70af8,fffffd8059172700) at syn_cache_add+0x66b tcp_input(ffff80001d678a18,ffff80001d678a24,6,2) at tcp_input+0x37f6 sys/netinet/tcp_input.c:830 ip_deliver(ffff80001d678a18,ffff80001d678a24,6,2) at ip_deliver+0x2e3 sys/netinet/ip_input.c:668 ip_ours(ffff80001d678a18,ffff80001d678a24,2,0) at ip_ours+0x4fe sys/netinet/ip_input.c:563 ip_input_if(ffff80001d678a18,ffff80001d678a24,4,0,ffff800000677800) at ip_input_if+0x571 ipv4_input(ffff800000677800,fffffd8059172700) at ipv4_input+0x48 sys/netinet/ip_input.c:215 if_input_local(ffff800000677800,fffffd8059172700,2) at if_input_local+0xf9 sys/net/if.c:769 loinput(ffff800000677800,fffffd8059172700,0) at loinput+0x4f sys/net/if_loop.c:239 if_input_process(ffff800000677800,ffff80001d678b68) at if_input_process+0xf8 if_ih_input sys/net/if.c:902 [inline] if_input_process(ffff800000677800,ffff80001d678b68) at if_input_process+0xf8 sys/net/if.c:936 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: 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(ffffffff823d8c2d) at panic+0x15c sys/kern/subr_prf.c:207 syn_cache_insert(fffffd8053899e80,ffff800000ac1000) at syn_cache_insert+0x944 sys/netinet/tcp_input.c:3235 syn_cache_add(ffff80001d678718,ffff80001d6786c8,fffffd80591727c4,14,fffffd805da70af8,fffffd8059172700) at syn_cache_add+0x66b tcp_input(ffff80001d678a18,ffff80001d678a24,6,2) at tcp_input+0x37f6 sys/netinet/tcp_input.c:830 ip_deliver(ffff80001d678a18,ffff80001d678a24,6,2) at ip_deliver+0x2e3 sys/netinet/ip_input.c:668 ip_ours(ffff80001d678a18,ffff80001d678a24,2,0) at ip_ours+0x4fe sys/netinet/ip_input.c:563 ip_input_if(ffff80001d678a18,ffff80001d678a24,4,0,ffff800000677800) at ip_input_if+0x571 ipv4_input(ffff800000677800,fffffd8059172700) at ipv4_input+0x48 sys/netinet/ip_input.c:215 if_input_local(ffff800000677800,fffffd8059172700,2) at if_input_local+0xf9 sys/net/if.c:769 loinput(ffff800000677800,fffffd8059172700,0) at loinput+0x4f sys/net/if_loop.c:239 if_input_process(ffff800000677800,ffff80001d678b68) at if_input_process+0xf8 if_ih_input sys/net/if.c:902 [inline] if_input_process(ffff800000677800,ffff80001d678b68) at if_input_process+0xf8 sys/net/if.c:936 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: -14 ddb> show registers rdi 0 rsi 0x1 rbp 0xffff80001d678290 rbx 0xffff80001d678340 rdx 0x2 rcx 0 rax 0x1 r8 0xffffffff810e305f kprintf+0x15f r9 0x1 r10 0x2 r11 0xcb9314e20596b45b r12 0x3000000008 r13 0xffff80001d6782a0 r14 0x100 r15 0x1 rip 0xffffffff8220f488 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff80001d678280 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb> show proc PROC (softnet) pid=212296 stat=onproc flags process=14000 proc=200 pri=32, usrpri=50, nice=20 forw=0xffffffffffffffff, list=0xffff80001d651000,0xffff80001d6514f0 process=0xffff8000ffffe398 user=0xffff80001d673000, vmspace=0xffffffff82854858 estcpu=0, cpticks=0, pctcpu=0.20 user=0, sys=0, intr=0 ddb> ps PID TID PPID UID S FLAGS WAIT COMMAND 98422 326509 18781 0 3 0x80 fsleep syz-executor.0 98422 420986 18781 0 2 0x4000000 syz-executor.0 26708 384560 34261 0 2 0 syz-executor.1 26708 245436 34261 0 3 0x4000080 netcon2 syz-executor.1 62194 451030 0 0 3 0x14200 bored sosplice 34261 518526 48570 0 3 0x82 nanosleep syz-executor.1 18781 242934 48570 0 3 0x82 nanosleep syz-executor.0 48570 338231 34310 0 3 0x82 thrsleep syz-fuzzer 48570 360191 34310 0 3 0x4000082 nanosleep syz-fuzzer 48570 363256 34310 0 3 0x4000082 kqread syz-fuzzer 48570 386569 34310 0 3 0x4000082 thrsleep syz-fuzzer 48570 308647 34310 0 3 0x4000082 thrsleep syz-fuzzer 48570 401196 34310 0 3 0x4000082 thrsleep syz-fuzzer 48570 191167 34310 0 3 0x4000082 thrsleep syz-fuzzer 48570 351507 34310 0 3 0x4000082 thrsleep syz-fuzzer 34310 315265 19583 0 3 0x10008a pause ksh 19583 433301 49080 0 3 0x92 select sshd 38007 62452 1 0 3 0x100083 ttyin getty 49080 207916 1 0 3 0x80 select sshd 98036 231854 14537 73 3 0x100090 kqread syslogd 14537 334998 1 0 3 0x100082 netio syslogd 65346 505352 1 77 3 0x100090 poll dhclient 10847 75827 1 0 3 0x80 poll dhclient 82995 24306 0 0 3 0x14200 bored smr 86400 35139 0 0 2 0x14200 zerothread 57664 236217 0 0 3 0x14200 aiodoned aiodoned 58550 165980 0 0 3 0x14200 syncer update 16138 259711 0 0 3 0x14200 cleaner cleaner 97700 247305 0 0 3 0x14200 reaper reaper 89775 421423 0 0 3 0x14200 pgdaemon pagedaemon 10271 451046 0 0 3 0x14200 bored crynlk 63572 268657 0 0 3 0x14200 bored crypto 71143 272693 0 0 3 0x40014200 acpi0 acpi0 *19018 212296 0 0 7 0x14200 softnet 7389 20950 0 0 3 0x14200 bored systqmp 249 409913 0 0 3 0x14200 bored systq 58431 252203 0 0 3 0x40014200 bored softclock 90241 287296 0 0 3 0x40014200 idle0 1 447131 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 9506 6418K 6725K 78643K 11028 0 pcb 13 8K 8K 78643K 47 0 rtable 121 6K 7K 78643K 322 0 ifaddr 82 16K 16K 78643K 116 0 sysctl 2 0K 0K 78643K 2 0 counters 21 16K 16K 78643K 22 0 ioctlops 0 0K 4K 78643K 55 0 iov 0 0K 12K 78643K 33 0 mount 1 1K 1K 78643K 1 0 vnodes 1218 77K 77K 78643K 1352 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 59 0 dirhash 12 2K 2K 78643K 12 0 ACPI 1809 195K 288K 78643K 12938 0 file desc 6 17K 25K 78643K 258 0 proc 50 38K 54K 78643K 369 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 13 0 in_multi 59 3K 3K 78643K 89 0 ether_multi 1 0K 0K 78643K 5 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 43 201K 201K 78643K 43 0 exec 0 0K 1K 78643K 196 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 131 39K 64K 78643K 1433 0 UVM aobj 6 2K 2K 78643K 6 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 12 0K 0K 78643K 19 0 temp 105 3866K 3930K 78643K 8773 0 kqueue 3 4K 8K 78643K 15 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 50 0 6 2 0 2 2 0 8 0 unpcb 120 157 0 149 1 0 1 1 0 8 0 syncache 264 8 0 7 3 2 1 1 0 8 0 tcpqe 32 509 0 509 2 2 0 1 0 8 0 tcpcb 544 75 0 69 1 0 1 1 0 8 0 ipq 40 2 0 2 1 0 1 1 0 8 1 ipqe 40 90 0 90 1 0 1 1 0 8 1 inpcb 296 230 0 221 3 1 2 2 0 8 1 rttmr 72 1 0 1 1 1 0 1 0 8 0 nd6 48 10 0 4 1 0 1 1 0 8 0 pfrktable 1344 35 0 30 2 1 1 1 0 8 0 pftag 88 8 0 6 2 1 1 1 0 8 0 pfrule 1360 16 0 7 1 0 1 1 0 8 0 art_heap8 4096 1 0 0 1 0 1 1 0 8 0 art_heap4 256 188 0 0 12 0 12 12 0 8 0 art_table 32 189 0 0 2 0 2 2 0 8 0 art_node 16 49 0 9 1 0 1 1 0 8 0 semupl 112 2 0 2 1 1 0 1 0 8 0 semapl 112 53 0 43 1 0 1 1 0 8 0 shmpl 112 4 0 0 1 0 1 1 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino2pl 256 1728 0 332 88 0 88 88 0 8 0 ffsino 240 1728 0 332 83 0 83 83 0 8 0 nchpl 144 2428 0 822 60 0 60 60 0 8 0 uvmvnodes 72 1870 0 0 34 0 34 34 0 8 0 vnodes 208 1870 0 0 99 0 99 99 0 8 0 namei 1024 6255 0 6255 1 0 1 1 0 8 1 vcpupl 1984 2 0 0 1 0 1 1 0 8 0 vmpool 528 4 0 2 1 0 1 1 0 8 0 pfiaddrpl 120 12 0 8 2 1 1 1 0 8 0 scxspl 192 6764 0 6764 1 0 1 1 0 8 1 plimitpl 152 37 0 30 1 0 1 1 0 8 0 sigapl 424 445 0 415 4 0 4 4 0 8 0 futexpl 56 5014 0 5013 1 0 1 1 0 8 0 knotepl 112 74 0 55 1 0 1 1 0 8 0 kqueuepl 144 39 0 36 1 0 1 1 0 8 0 pipelkpl 16 110 0 100 1 0 1 1 0 8 0 pipepl 120 220 0 201 2 0 2 2 0 8 1 fdescpl 432 430 0 415 2 0 2 2 0 8 0 filepl 120 2666 0 2566 4 0 4 4 0 8 0 lockfpl 104 41 0 40 1 0 1 1 0 8 0 lockfspl 48 17 0 16 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 96 208 0 201 1 0 1 1 0 8 0 zombiepl 144 415 0 415 1 0 1 1 0 8 1 processpl 920 445 0 415 4 0 4 4 0 8 0 procpl 624 715 0 676 4 0 4 4 0 8 1 sosppl 128 5 0 5 2 1 1 1 0 8 1 sockpl 400 426 0 407 3 0 3 3 0 8 1 mcl64k 65536 20 0 20 1 0 1 1 0 8 1 mcl16k 16384 2 0 2 2 1 1 1 0 8 1 mcl12k 12288 5 0 5 2 1 1 1 0 8 1 mcl9k 9216 5 0 5 2 1 1 1 0 8 1 mcl8k 8192 8 0 8 2 1 1 1 0 8 1 mcl4k 4096 31 0 31 2 1 1 1 0 8 1 mcl2k2 2112 2 0 2 2 1 1 1 0 8 1 mcl2k 2048 73195 0 73141 26 18 8 20 0 8 0 mtagpl 96 42 0 5 2 1 1 1 0 8 0 mbufpl 256 119312 0 119126 23 2 21 22 0 8 8 bufpl 280 5898 0 546 383 0 383 383 0 8 0 anonpl 16 58649 0 44122 87 5 82 82 0 107 16 amapchunkpl 152 2226 0 2096 23 4 19 19 0 158 13 amappl16 192 2032 0 1141 57 4 53 57 0 8 8 amappl15 184 2 0 0 1 0 1 1 0 8 0 amappl14 176 138 0 130 1 0 1 1 0 8 0 amappl13 168 250 0 243 1 0 1 1 0 8 0 amappl12 160 129 0 124 1 0 1 1 0 8 0 amappl11 152 46 0 37 1 0 1 1 0 8 0 amappl10 144 16 0 10 1 0 1 1 0 8 0 amappl9 136 377 0 376 1 0 1 1 0 8 0 amappl8 128 331 0 288 2 0 2 2 0 8 0 amappl7 120 106 0 94 1 0 1 1 0 8 0 amappl6 112 22 0 18 1 0 1 1 0 8 0 amappl5 104 256 0 244 1 0 1 1 0 8 0 amappl4 96 533 0 506 1 0 1 1 0 8 0 amappl3 88 220 0 213 1 0 1 1 0 8 0 amappl2 80 2712 0 2636 2 0 2 2 0 8 0 amappl1 72 16876 0 16453 22 12 10 17 0 8 0 amappl 80 942 0 900 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 5 0 0 1 0 1 1 0 8 0 uaddrrnd 24 434 0 417 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 434 0 417 1 0 1 1 0 8 0 vmmpekpl 168 6758 0 6729 2 0 2 2 0 8 0 vmmpepl 168 57515 0 55436 110 9 101 106 0 357 10 vmsppl 272 433 0 417 2 0 2 2 0 8 0 pdppl 4096 874 0 836 6 1 5 6 0 8 0 pvpl 32 179508 0 161907 196 3 193 193 0 265 38 pmappl 200 433 0 417 1 0 1 1 0 8 0 extentpl 40 53 0 36 1 0 1 1 0 8 0 phpool 112 263 0 26 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(ffffffff823d8c2d) at panic+0x15c sys/kern/subr_prf.c:207 syn_cache_insert(fffffd8053899e80,ffff800000ac1000) at syn_cache_insert+0x944 sys/netinet/tcp_input.c:3235 syn_cache_add(ffff80001d678718,ffff80001d6786c8,fffffd80591727c4,14,fffffd805da70af8,fffffd8059172700) at syn_cache_add+0x66b tcp_input(ffff80001d678a18,ffff80001d678a24,6,2) at tcp_input+0x37f6 sys/netinet/tcp_input.c:830 ip_deliver(ffff80001d678a18,ffff80001d678a24,6,2) at ip_deliver+0x2e3 sys/netinet/ip_input.c:668 ip_ours(ffff80001d678a18,ffff80001d678a24,2,0) at ip_ours+0x4fe sys/netinet/ip_input.c:563 ip_input_if(ffff80001d678a18,ffff80001d678a24,4,0,ffff800000677800) at ip_input_if+0x571 ipv4_input(ffff800000677800,fffffd8059172700) at ipv4_input+0x48 sys/netinet/ip_input.c:215 if_input_local(ffff800000677800,fffffd8059172700,2) at if_input_local+0xf9 sys/net/if.c:769 loinput(ffff800000677800,fffffd8059172700,0) at loinput+0x4f sys/net/if_loop.c:239 if_input_process(ffff800000677800,ffff80001d678b68) at if_input_process+0xf8 if_ih_input sys/net/if.c:902 [inline] if_input_process(ffff800000677800,ffff80001d678b68) at if_input_process+0xf8 sys/net/if.c:936 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: -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(ffffffff823d8c2d) at panic+0x15c sys/kern/subr_prf.c:207 syn_cache_insert(fffffd8053899e80,ffff800000ac1000) at syn_cache_insert+0x944 sys/netinet/tcp_input.c:3235 syn_cache_add(ffff80001d678718,ffff80001d6786c8,fffffd80591727c4,14,fffffd805da70af8,fffffd8059172700) at syn_cache_add+0x66b tcp_input(ffff80001d678a18,ffff80001d678a24,6,2) at tcp_input+0x37f6 sys/netinet/tcp_input.c:830 ip_deliver(ffff80001d678a18,ffff80001d678a24,6,2) at ip_deliver+0x2e3 sys/netinet/ip_input.c:668 ip_ours(ffff80001d678a18,ffff80001d678a24,2,0) at ip_ours+0x4fe sys/netinet/ip_input.c:563 ip_input_if(ffff80001d678a18,ffff80001d678a24,4,0,ffff800000677800) at ip_input_if+0x571 ipv4_input(ffff800000677800,fffffd8059172700) at ipv4_input+0x48 sys/netinet/ip_input.c:215 if_input_local(ffff800000677800,fffffd8059172700,2) at if_input_local+0xf9 sys/net/if.c:769 loinput(ffff800000677800,fffffd8059172700,0) at loinput+0x4f sys/net/if_loop.c:239 if_input_process(ffff800000677800,ffff80001d678b68) at if_input_process+0xf8 if_ih_input sys/net/if.c:902 [inline] if_input_process(ffff800000677800,ffff80001d678b68) at if_input_process+0xf8 sys/net/if.c:936 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: -14