panic(ffffffff821cc699) at panic+0x15c sys/kern/subr_prf.c:207 pool_cache_get(ffffffff82622e18) at pool_cache_get+0x323 pool_cache_item_magic_check sys/kern/subr_pool.c:1789 [inline] pool_cache_get(ffffffff82622e18) at pool_cache_get+0x323 sys/kern/subr_pool.c:1892 pool_get(ffffffff82622e18,2) at pool_get+0x91 sys/kern/subr_pool.c:572 m_gethdr(2,2) at m_gethdr+0x4c sys/kern/uipc_mbuf.c:283 tcp_output(ffff800000a04760) at tcp_output+0x14e6 tcp_usrreq(fffffd806e95da88,9,fffffd8066e38d00,0,0,ffff800020ad9b38) at tcp_usrreq+0xa55 sosend(fffffd806e95da88,0,ffff800020b03328,0,0,80) at sosend+0x671 sys/kern/uipc_socket.c:538 dofilewritev(ffff800020ad9b38,4,ffff800020b03328,0,ffff800020b03410) at dofilewritev+0x1b7 sys/kern/sys_generic.c:364 sys_write(ffff800020ad9b38,ffff800020b033c0,ffff800020b03410) at sys_write+0x83 sys/kern/sys_generic.c:284 syscall(ffff800020b03490) at syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:92 [inline] syscall(ffff800020b03490) at syscall+0x4a4 sys/arch/amd64/amd64/trap.c:570 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7f7ffffe3e30, count: 3 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{0}> ddb{0}> set $lines = 0 ddb{0}> set $maxwidth = 0 ddb{0}> show panic pool_cache_item_magic_check: mbufpl cpu free list modified: item addr 0xfffffd8066e31c00+24 0xcc422aaa20588537!=0xcc422a2a46bbe837 ddb{0}> trace db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:398 panic(ffffffff821cc699) at panic+0x15c sys/kern/subr_prf.c:207 pool_cache_get(ffffffff82622e18) at pool_cache_get+0x323 pool_cache_item_magic_check sys/kern/subr_pool.c:1789 [inline] pool_cache_get(ffffffff82622e18) at pool_cache_get+0x323 sys/kern/subr_pool.c:1892 pool_get(ffffffff82622e18,2) at pool_get+0x91 sys/kern/subr_pool.c:572 m_gethdr(2,2) at m_gethdr+0x4c sys/kern/uipc_mbuf.c:283 tcp_output(ffff800000a04760) at tcp_output+0x14e6 tcp_usrreq(fffffd806e95da88,9,fffffd8066e38d00,0,0,ffff800020ad9b38) at tcp_usrreq+0xa55 sosend(fffffd806e95da88,0,ffff800020b03328,0,0,80) at sosend+0x671 sys/kern/uipc_socket.c:538 dofilewritev(ffff800020ad9b38,4,ffff800020b03328,0,ffff800020b03410) at dofilewritev+0x1b7 sys/kern/sys_generic.c:364 sys_write(ffff800020ad9b38,ffff800020b033c0,ffff800020b03410) at sys_write+0x83 sys/kern/sys_generic.c:284 syscall(ffff800020b03490) at syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:92 [inline] syscall(ffff800020b03490) at syscall+0x4a4 sys/arch/amd64/amd64/trap.c:570 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7f7ffffe3e30, count: -12 ddb{0}> show registers rdi 0 rsi 0x1 rbp 0xffff800020b02d20 rbx 0xffff800020b02dd0 rdx 0xffff800020ad9b38 rcx 0 rax 0 r8 0xffffffff81a8283f kprintf+0x16f r9 0x1 r10 0x25 r11 0xebbde2159b6835c2 r12 0x3000000008 r13 0xffff800020b02d30 r14 0x100 r15 0x1 rip 0xffffffff812c53f8 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff800020b02d10 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{0}> show proc PROC (sshd) pid=449625 stat=onproc flags process=12 proc=0 pri=56, usrpri=56, nice=20 forw=0xffffffffffffffff, list=0xffff800020ad93d0,0xffff800020ad8c78 process=0xffff800020aa3890 user=0xffff800020afe000, vmspace=0xfffffd806e79f178 estcpu=6, cpticks=21, pctcpu=0.0 user=0, sys=19, intr=2 ddb{0}> ps PID TID PPID UID S FLAGS WAIT COMMAND 48410 397431 71017 0 2 0 syz-executor.0 48410 114077 71017 0 2 0x4000000 syz-executor.0 20999 425330 0 0 3 0x14200 acct acct 71017 173387 733 0 3 0x82 nanosleep syz-executor.0 43356 271909 733 0 7 0x2 syz-executor.1 57798 381623 1 0 3 0x100083 ttyin getty 93909 5498 0 0 3 0x14200 bored sosplice 733 68871 78922 0 3 0x82 nanosleep syz-fuzzer 733 470365 78922 0 3 0x4000082 nanosleep syz-fuzzer 733 428661 78922 0 3 0x4000082 thrsleep syz-fuzzer 733 326223 78922 0 3 0x4000082 thrsleep syz-fuzzer 733 462632 78922 0 3 0x4000082 thrsleep syz-fuzzer 733 401557 78922 0 3 0x4000082 thrsleep syz-fuzzer 733 486226 78922 0 3 0x4000082 kqread syz-fuzzer 733 149088 78922 0 3 0x4000082 thrsleep syz-fuzzer 733 168041 78922 0 3 0x4000082 thrsleep syz-fuzzer 733 264808 78922 0 3 0x4000082 thrsleep syz-fuzzer 78922 230935 13222 0 3 0x10008a pause ksh *13222 449625 82486 0 7 0x12 sshd 82486 418357 1 0 3 0x80 select sshd 71306 245932 79353 74 3 0x100092 bpf pflogd 79353 442959 1 0 3 0x80 netio pflogd 93366 115149 38384 73 3 0x100090 kqread syslogd 38384 188853 1 0 3 0x100082 netio syslogd 55365 282159 1 77 3 0x100090 poll dhclient 95279 257483 1 0 3 0x80 poll dhclient 64 251218 0 0 2 0x14200 zerothread 66164 343215 0 0 3 0x14200 aiodoned aiodoned 6077 216881 0 0 3 0x14200 syncer update 19717 103115 0 0 3 0x14200 cleaner cleaner 64718 30630 0 0 3 0x14200 reaper reaper 13027 232993 0 0 3 0x14200 pgdaemon pagedaemon 2398 303883 0 0 3 0x14200 bored crynlk 98691 160269 0 0 3 0x14200 bored crypto 52263 354169 0 0 3 0x40014200 acpi0 acpi0 39719 137433 0 0 3 0x40014200 idle1 23253 110050 0 0 3 0x14200 bored softnet 87163 230933 0 0 3 0x14200 bored systqmp 25832 332209 0 0 3 0x14200 bored systq 56256 88908 0 0 3 0x40014200 bored softclock 87537 441942 0 0 3 0x40014200 idle0 3619 359428 0 0 3 0x14200 bored smr 1 423606 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb{0}> show all locks Process 43356 (syz-executor.1) thread 0xffff800020ac89f8 (271909) exclusive rwlock fdlock r = 0 (0xfffffd806e677448) #0 witness_lock+0x52e sys/kern/subr_witness.c:1163 #1 doopenat+0x123 sys/kern/vfs_syscalls.c:1118 #2 syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:92 [inline] #2 syscall+0x4a4 sys/arch/amd64/amd64/trap.c:570 #3 Xsyscall+0x128 exclusive kernel_lock &kernel_lock r = 0 (0xffffffff82663708) #0 witness_lock+0x52e sys/kern/subr_witness.c:1163 #1 syscall+0x400 mi_syscall sys/sys/syscall_mi.h:83 [inline] #1 syscall+0x400 sys/arch/amd64/amd64/trap.c:570 #2 Xsyscall+0x128 Process 13222 (sshd) thread 0xffff800020ad9b38 (449625) exclusive rwlock netlock r = 0 (0xffffffff824f3c18) #0 witness_lock+0x52e sys/kern/subr_witness.c:1163 #1 solock+0x5a sys/kern/uipc_socket2.c:282 #2 sosend+0x559 sys/kern/uipc_socket.c:526 #3 dofilewritev+0x1b7 sys/kern/sys_generic.c:364 #4 sys_write+0x83 sys/kern/sys_generic.c:284 #5 syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:92 [inline] #5 syscall+0x4a4 sys/arch/amd64/amd64/trap.c:570 #6 Xsyscall+0x128 ddb{0}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim devbuf 9524 6544K 7190K 78643K 11751 0 pcb 13 9K 9K 78643K 108 0 rtable 113 12K 12K 78643K 433 0 ifaddr 85 17K 17K 78643K 183 0 counters 39 33K 33K 78643K 39 0 ioctlops 0 0K 4K 78643K 1499 0 iov 0 0K 28K 78643K 96 0 mount 1 1K 1K 78643K 1 0 vnodes 1221 77K 77K 78643K 1623 0 UFS quota 1 32K 32K 78643K 1 0 UFS mount 5 36K 36K 78643K 5 0 shm 2 1K 5K 78643K 10 0 VM map 2 1K 1K 78643K 2 0 sem 12 0K 0K 78643K 198 0 dirhash 12 2K 2K 78643K 12 0 ACPI 1809 196K 290K 78643K 12766 0 file desc 5 13K 25K 78643K 642 0 sigio 0 0K 0K 78643K 12 0 proc 61 63K 83K 78643K 582 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 49 0 in_multi 95 4K 4K 78643K 147 0 ether_multi 1 0K 0K 78643K 11 0 mrt 0 0K 0K 78643K 10 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 276 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 117 54K 56K 78643K 3010 0 UVM aobj 117 5K 5K 78643K 117 0 memdesc 1 4K 4K 78643K 1 0 crypto data 1 1K 1K 78643K 1 0 ip6_options 0 0K 0K 78643K 44 0 NDP 12 0K 0K 78643K 36 0 temp 132 3018K 3094K 78643K 21637 0 kqueue 3 4K 16K 78643K 46 0 SYN cache 2 16K 16K 78643K 2 0 ddb{0}> show all pools Name Size Requests Fail Releases Pgreq Pgrel Npage Hiwat Minpg Maxpg Idle arp 64 12 0 5 1 0 1 1 0 8 0 plcache 128 20 0 0 1 0 1 1 0 8 0 rtpcb 80 50 0 48 1 0 1 1 0 8 0 rtentry 112 83 0 38 2 0 2 2 0 8 0 unpcb 120 267 0 257 1 0 1 1 0 8 0 syncache 264 7 0 7 2 2 0 1 0 8 0 tcpqe 32 181 0 181 2 2 0 1 0 8 0 tcpcb 544 225 0 221 2 1 1 2 0 8 0 inpcb 280 1157 0 1150 4 1 3 3 0 8 2 rttmr 72 4 0 4 2 2 0 1 0 8 0 nd6 48 10 0 6 1 0 1 1 0 8 0 pkpcb 40 1 0 1 1 1 0 1 0 8 0 ppxss 1128 11 0 11 4 3 1 1 0 8 1 pffrag 232 10 0 10 2 2 0 1 0 482 0 pffrnode 88 10 0 10 2 2 0 1 0 8 0 pffrent 40 246 0 246 3 3 0 1 0 8 0 pfosfp 40 846 0 423 5 0 5 5 0 8 0 pfosfpen 112 1428 0 714 21 0 21 21 0 8 0 pfstitem 24 43 0 12 1 0 1 1 0 8 0 pfstkey 112 43 0 12 1 0 1 1 0 8 0 pfstate 328 43 0 12 3 0 3 3 0 8 0 pfrule 1360 21 0 16 2 1 1 2 0 8 0 art_heap8 4096 1 0 0 1 0 1 1 0 8 0 art_heap4 256 390 0 163 17 2 15 16 0 8 0 art_table 32 391 0 163 3 1 2 3 0 8 0 art_node 16 82 0 41 1 0 1 1 0 8 0 sysvmsgpl 40 14 0 9 1 0 1 1 0 8 0 semupl 112 2 0 2 1 1 0 1 0 8 0 semapl 112 196 0 186 1 0 1 1 0 8 0 shmpl 112 115 0 0 4 0 4 4 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino1pl 128 2414 0 1005 46 0 46 46 0 8 0 ffsino 272 2414 0 1005 95 0 95 95 0 8 0 nchpl 144 3651 0 2047 61 0 61 61 0 8 0 uvmvnodes 72 2765 0 0 51 0 51 51 0 8 0 vnodes 208 2765 0 0 146 0 146 146 0 8 0 namei 1024 10114 0 10114 1 0 1 1 0 8 1 percpumem 16 30 0 0 1 0 1 1 0 8 0 vcpupl 1984 3 0 0 1 0 1 1 0 8 0 vmpool 560 5 0 2 1 0 1 1 0 8 0 scxspl 192 10115 0 10114 8 7 1 7 0 8 0 plimitpl 152 46 0 38 1 0 1 1 0 8 0 sigapl 432 836 0 821 3 1 2 3 0 8 0 futexpl 56 11807 0 11807 1 0 1 1 0 8 1 knotepl 112 138 0 119 1 0 1 1 0 8 0 kqueuepl 104 114 0 112 1 0 1 1 0 8 0 pipelkpl 48 518 0 508 1 0 1 1 0 8 0 pipepl 120 1036 0 1017 3 1 2 2 0 8 1 fdescpl 496 837 0 821 3 0 3 3 0 8 0 filepl 152 6098 0 5998 7 1 6 6 0 8 2 lockfpl 104 153 0 152 1 0 1 1 0 8 0 lockfspl 48 61 0 60 1 0 1 1 0 8 0 sessionpl 112 21 0 10 1 0 1 1 0 8 0 pgrppl 48 30 0 19 1 0 1 1 0 8 0 ucredpl 96 512 0 502 1 0 1 1 0 8 0 zombiepl 144 822 0 822 1 0 1 1 0 8 1 processpl 896 855 0 822 4 0 4 4 0 8 0 procpl 632 2130 0 2087 6 1 5 5 0 8 1 sosppl 128 12 0 12 2 2 0 1 0 8 0 sockpl 384 1492 0 1473 8 3 5 6 0 8 3 mcl64k 65536 14 0 0 2 0 2 2 0 8 0 mcl16k 16384 2 0 0 1 0 1 1 0 8 0 mcl12k 12288 4 0 0 1 0 1 1 0 8 0 mcl9k 9216 7 0 0 1 0 1 1 0 8 0 mcl8k 8192 10 0 0 2 0 2 2 0 8 0 mcl4k 4096 18 0 0 3 0 3 3 0 8 1 mcl2k2 2112 2 0 0 1 0 1 1 0 8 0 mcl2k 2048 336 0 0 41 0 41 41 0 8 0 mtagpl 80 32 0 0 1 0 1 1 0 8 0 mbufpl 256 349 0 0 22 1 21 21 0 8 0 bufpl 280 7598 0 1344 447 0 447 447 0 8 0 anonpl 16 94538 0 78835 85 6 79 79 0 125 15 amapchunkpl 152 4795 0 4664 19 13 6 19 0 158 0 amappl16 192 3739 0 2886 67 17 50 55 0 8 7 amappl15 184 460 0 455 1 0 1 1 0 8 0 amappl14 176 287 0 283 1 0 1 1 0 8 0 amappl13 168 1 0 1 1 1 0 1 0 8 0 amappl12 160 8 0 8 1 1 0 1 0 8 0 amappl11 152 141 0 124 1 0 1 1 0 8 0 amappl10 144 14 0 8 1 0 1 1 0 8 0 amappl9 136 701 0 698 1 0 1 1 0 8 0 amappl8 128 215 0 192 1 0 1 1 0 8 0 amappl7 120 121 0 106 1 0 1 1 0 8 0 amappl6 112 135 0 126 1 0 1 1 0 8 0 amappl5 104 150 0 136 1 0 1 1 0 8 0 amappl4 96 1105 0 1070 1 0 1 1 0 8 0 amappl3 88 367 0 358 1 0 1 1 0 8 0 amappl2 80 5876 0 5802 3 1 2 3 0 8 0 amappl1 72 27773 0 27322 27 17 10 21 0 8 0 amappl 80 2413 0 2369 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 64 116 0 0 2 0 2 2 0 8 0 uaddrrnd 24 842 0 823 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 842 0 823 1 0 1 1 0 8 0 vmmpekpl 168 10877 0 10837 2 0 2 2 0 8 0 vmmpepl 168 108857 0 106825 141 29 112 118 0 357 20 vmsppl 368 841 0 823 2 0 2 2 0 8 0 pdppl 4096 1691 0 1649 6 0 6 6 0 8 0 pvpl 32 280472 0 261545 200 10 190 190 0 265 37 pmappl 232 841 0 823 2 0 2 2 0 8 0 extentpl 40 46 0 29 1 0 1 1 0 8 0 phpool 112 202 0 7 6 0 6 6 0 8 0