panic(ffffffff821d3a7e) at panic+0x15c sys/kern/subr_prf.c:207 pool_cache_get(ffffffff826473e8) at pool_cache_get+0x323 pool_cache_item_magic_check sys/kern/subr_pool.c:1781 [inline] pool_cache_get(ffffffff826473e8) at pool_cache_get+0x323 sys/kern/subr_pool.c:1884 pool_get(ffffffff826473e8,2) at pool_get+0x91 sys/kern/subr_pool.c:572 m_copym(fffffd807f01f800,0,580,2) at m_copym+0x174 m_get sys/kern/uipc_mbuf.c:250 [inline] m_copym(fffffd807f01f800,0,580,2) at m_copym+0x174 sys/kern/uipc_mbuf.c:667 tcp_output(ffff800000a03aa0) at tcp_output+0x15ba sys/netinet/tcp_output.c:673 tcp_usrreq(fffffd806f6e2640,9,fffffd807f01f800,0,0,ffff800020ae1ae0) at tcp_usrreq+0xa55 sosend(fffffd806f6e2640,0,ffff800020b03d18,0,0,80) at sosend+0x671 sys/kern/uipc_socket.c:549 dofilewritev(ffff800020ae1ae0,4,ffff800020b03d18,0,ffff800020b03e00) at dofilewritev+0x1b7 sys/kern/sys_generic.c:364 sys_write(ffff800020ae1ae0,ffff800020b03db0,ffff800020b03e00) at sys_write+0x83 sys/kern/sys_generic.c:284 syscall(ffff800020b03e80) at syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:102 [inline] syscall(ffff800020b03e80) at syscall+0x4a4 sys/arch/amd64/amd64/trap.c:570 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7f7ffffc74a0, 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 0xfffffd806b946e00+24 0xb96622d16b77ae4f!=0xb999df5100e3f74f ddb{0}> trace db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:398 panic(ffffffff821d3a7e) at panic+0x15c sys/kern/subr_prf.c:207 pool_cache_get(ffffffff826473e8) at pool_cache_get+0x323 pool_cache_item_magic_check sys/kern/subr_pool.c:1781 [inline] pool_cache_get(ffffffff826473e8) at pool_cache_get+0x323 sys/kern/subr_pool.c:1884 pool_get(ffffffff826473e8,2) at pool_get+0x91 sys/kern/subr_pool.c:572 m_copym(fffffd807f01f800,0,580,2) at m_copym+0x174 m_get sys/kern/uipc_mbuf.c:250 [inline] m_copym(fffffd807f01f800,0,580,2) at m_copym+0x174 sys/kern/uipc_mbuf.c:667 tcp_output(ffff800000a03aa0) at tcp_output+0x15ba sys/netinet/tcp_output.c:673 tcp_usrreq(fffffd806f6e2640,9,fffffd807f01f800,0,0,ffff800020ae1ae0) at tcp_usrreq+0xa55 sosend(fffffd806f6e2640,0,ffff800020b03d18,0,0,80) at sosend+0x671 sys/kern/uipc_socket.c:549 dofilewritev(ffff800020ae1ae0,4,ffff800020b03d18,0,ffff800020b03e00) at dofilewritev+0x1b7 sys/kern/sys_generic.c:364 sys_write(ffff800020ae1ae0,ffff800020b03db0,ffff800020b03e00) at sys_write+0x83 sys/kern/sys_generic.c:284 syscall(ffff800020b03e80) at syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:102 [inline] syscall(ffff800020b03e80) at syscall+0x4a4 sys/arch/amd64/amd64/trap.c:570 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7f7ffffc74a0, count: -12 ddb{0}> show registers rdi 0 rsi 0x1 rbp 0xffff800020b036b0 rbx 0xffff800020b03760 rdx 0xffff800020ae1ae0 rcx 0 rax 0 r8 0xffffffff81801dcf kprintf+0x16f r9 0x1 r10 0x25 r11 0x44e021fce12dfd3c r12 0x3000000008 r13 0xffff800020b036c0 r14 0x100 r15 0x1 rip 0xffffffff81c8fc08 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff800020b036a0 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{0}> show proc PROC (sshd) pid=489213 stat=onproc flags process=12 proc=0 pri=50, usrpri=50, nice=20 forw=0xffffffffffffffff, list=0xffff800020ae0c40,0xffff800020ae09e0 process=0xffff800020ad8b58 user=0xffff800020afe000, vmspace=0xfffffd806e921458 estcpu=0, cpticks=2, pctcpu=0.0 user=0, sys=2, intr=0 ddb{0}> ps PID TID PPID UID S FLAGS WAIT COMMAND 59042 132530 65604 0 2 0 syz-executor.1 59042 411249 65604 0 3 0x4000080 netcon syz-executor.1 59042 485446 65604 0 7 0x4000000 syz-executor.1 16752 199286 0 0 3 0x14200 acct acct 35166 477051 0 0 3 0x14200 bored sosplice 65604 46001 97512 0 3 0x82 nanosleep syz-executor.1 72419 497433 97512 0 2 0x82 syz-executor.0 97512 472311 37350 0 2 0x82 syz-fuzzer 97512 450920 37350 0 3 0x4000082 nanosleep syz-fuzzer 97512 428725 37350 0 3 0x4000082 thrsleep syz-fuzzer 97512 365588 37350 0 3 0x4000082 thrsleep syz-fuzzer 97512 207999 37350 0 3 0x4000082 thrsleep syz-fuzzer 97512 111315 37350 0 3 0x4000082 thrsleep syz-fuzzer 97512 164647 37350 0 3 0x4000082 thrsleep syz-fuzzer 97512 115074 37350 0 2 0x4000082 syz-fuzzer 97512 354117 37350 0 3 0x4000082 thrsleep syz-fuzzer 97512 226291 37350 0 3 0x4000082 thrsleep syz-fuzzer 37350 152065 53216 0 3 0x10008a pause ksh *53216 489213 90360 0 7 0x12 sshd 28701 144463 1 0 3 0x100083 ttyin getty 90360 153173 1 0 3 0x80 select sshd 28331 402729 22526 74 3 0x100092 bpf pflogd 22526 162196 1 0 3 0x80 netio pflogd 99871 294035 91087 73 3 0x100090 kqread syslogd 91087 403748 1 0 3 0x100082 netio syslogd 89264 367939 1 77 3 0x100090 poll dhclient 30300 426250 1 0 3 0x80 poll dhclient 21611 457861 0 0 2 0x14200 zerothread 91223 427350 0 0 3 0x14200 aiodoned aiodoned 95593 237958 0 0 3 0x14200 syncer update 20920 88548 0 0 3 0x14200 cleaner cleaner 9490 81993 0 0 3 0x14200 reaper reaper 4979 102554 0 0 3 0x14200 pgdaemon pagedaemon 79346 17186 0 0 3 0x14200 bored crynlk 84429 216593 0 0 3 0x14200 bored crypto 44164 415453 0 0 3 0x40014200 acpi0 acpi0 40000 44695 0 0 3 0x40014200 idle1 46578 350543 0 0 3 0x14200 bored softnet 29377 426498 0 0 3 0x14200 bored systqmp 81625 57077 0 0 3 0x14200 bored systq 47283 12200 0 0 3 0x40014200 bored softclock 53006 359922 0 0 3 0x40014200 idle0 63103 39296 0 0 3 0x14200 bored smr 1 339200 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb{0}> show all locks Process 53216 (sshd) thread 0xffff800020ae1ae0 (489213) exclusive rwlock netlock r = 0 (0xffffffff82455738) #0 witness_lock+0x52e sys/kern/subr_witness.c:1164 #1 solock+0x5a sys/kern/uipc_socket2.c:282 #2 sosend+0x559 sys/kern/uipc_socket.c:537 #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:102 [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 9514 6477K 6933K 78643K 11214 0 pcb 13 8K 8K 78643K 77 0 rtable 112 12K 12K 78643K 368 0 ifaddr 73 15K 15K 78643K 147 0 counters 43 33K 34K 78643K 67 0 ioctlops 0 0K 4K 78643K 1484 0 iov 0 0K 16K 78643K 312 0 mount 1 1K 1K 78643K 1 0 vnodes 1220 77K 77K 78643K 1425 0 UFS quota 1 32K 32K 78643K 1 0 UFS mount 5 36K 36K 78643K 5 0 shm 2 1K 5K 78643K 8 0 VM map 2 1K 1K 78643K 2 0 sem 12 0K 0K 78643K 63 0 dirhash 12 2K 2K 78643K 12 0 ACPI 1809 196K 290K 78643K 12766 0 file desc 5 13K 25K 78643K 312 0 sigio 0 0K 0K 78643K 4 0 proc 61 63K 83K 78643K 472 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 54 0 in_multi 54 2K 3K 78643K 99 0 ether_multi 1 0K 0K 78643K 11 0 ISOFS mount 1 32K 32K 78643K 1 0 MSDOSFS mount 1 16K 16K 78643K 1 0 ttys 49 228K 228K 78643K 49 0 exec 0 0K 1K 78643K 248 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 118 38K 42K 78643K 2137 0 UVM aobj 12 4K 4K 78643K 20 0 memdesc 1 4K 4K 78643K 1 0 crypto data 1 1K 1K 78643K 1 0 ip6_options 0 0K 0K 78643K 58 0 NDP 11 0K 0K 78643K 29 0 temp 128 3022K 3155K 78643K 4117 0 kqueue 3 4K 16K 78643K 33 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 8 0 1 1 0 1 1 0 8 0 plcache 128 20 0 0 1 0 1 1 0 8 0 rtpcb 80 66 0 64 1 0 1 1 0 8 0 rtentry 112 59 0 16 2 0 2 2 0 8 0 unpcb 120 250 0 240 1 0 1 1 0 8 0 syncache 264 4 0 4 1 1 0 1 0 8 0 tcpqe 32 374 0 374 2 2 0 1 0 8 0 tcpcb 544 214 0 209 1 0 1 1 0 8 0 inpcb 280 618 0 610 2 0 2 2 0 8 1 nd6 48 6 0 4 1 0 1 1 0 8 0 pkpcb 40 4 0 4 1 1 0 1 0 8 0 ppxss 1128 1 0 1 1 1 0 1 0 8 0 pffrag 232 11 0 11 2 1 1 1 0 482 1 pffrnode 88 11 0 11 2 1 1 1 0 8 1 pffrent 40 367 0 367 2 1 1 1 0 8 1 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 47 0 10 1 0 1 1 0 8 0 pfstkey 112 47 0 10 2 0 2 2 0 8 0 pfstate 328 47 0 9 4 0 4 4 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 256 278 0 80 16 3 13 14 0 8 0 art_table 32 279 0 80 2 0 2 2 0 8 0 art_node 16 58 0 17 1 0 1 1 0 8 0 sysvmsgpl 40 88 0 48 1 0 1 1 0 8 0 semupl 112 6 0 6 1 1 0 1 0 8 0 semapl 112 57 0 47 1 0 1 1 0 8 0 shmpl 112 18 0 8 1 0 1 1 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino1pl 128 1858 0 454 46 0 46 46 0 8 0 ffsino 272 1858 0 454 95 0 95 95 0 8 0 nchpl 144 2587 0 971 61 0 61 61 0 8 0 uvmvnodes 72 2045 0 0 38 0 38 38 0 8 0 vnodes 208 2045 0 0 108 0 108 108 0 8 0 namei 1024 7338 0 7338 2 1 1 1 0 8 1 percpumem 16 44 0 12 1 0 1 1 0 8 0 vcpupl 1984 2 0 0 1 0 1 1 0 8 0 vmpool 560 4 0 2 2 1 1 1 0 8 0 scxspl 192 7769 0 7769 10 8 2 7 0 8 2 plimitpl 152 32 0 24 1 0 1 1 0 8 0 sigapl 432 511 0 496 3 1 2 3 0 8 0 futexpl 56 6376 0 6376 1 0 1 1 0 8 1 knotepl 112 98 0 79 1 0 1 1 0 8 0 kqueuepl 104 182 0 180 1 0 1 1 0 8 0 pipelkpl 48 132 0 121 1 0 1 1 0 8 0 pipepl 120 264 0 243 1 0 1 1 0 8 0 fdescpl 496 512 0 496 3 0 3 3 0 8 0 filepl 152 3974 0 3869 9 3 6 6 0 8 1 lockfpl 104 146 0 145 1 0 1 1 0 8 0 lockfspl 48 41 0 40 1 0 1 1 0 8 0 sessionpl 112 18 0 7 1 0 1 1 0 8 0 pgrppl 48 48 0 37 1 0 1 1 0 8 0 ucredpl 96 431 0 422 1 0 1 1 0 8 0 zombiepl 144 496 0 496 2 1 1 1 0 8 1 processpl 960 529 0 496 6 1 5 5 0 8 0 procpl 624 1322 0 1278 6 1 5 5 0 8 1 sosppl 128 9 0 9 1 0 1 1 0 8 1 sockpl 400 944 0 924 5 2 3 5 0 8 0 mcl64k 65536 26 0 0 4 0 4 4 0 8 0 mcl16k 16384 2 0 0 1 0 1 1 0 8 0 mcl12k 12288 6 0 0 1 0 1 1 0 8 0 mcl9k 9216 4 0 0 1 0 1 1 0 8 0 mcl8k 8192 3 0 0 1 0 1 1 0 8 0 mcl4k 4096 6 0 0 1 0 1 1 0 8 0 mcl2k2 2112 2 0 0 1 0 1 1 0 8 0 mcl2k 2048 172 0 0 21 0 21 21 0 8 0 mtagpl 80 28 0 0 1 0 1 1 0 8 0 mbufpl 256 384 0 0 22 0 22 22 0 8 0 bufpl 280 4872 0 195 335 0 335 335 0 8 0 anonpl 16 62561 0 45921 78 8 70 75 0 125 1 amapchunkpl 152 3045 0 2899 12 4 8 11 0 158 0 amappl16 192 2290 0 1397 50 3 47 48 0 8 2 amappl15 184 58 0 55 1 0 1 1 0 8 0 amappl14 176 29 0 26 1 0 1 1 0 8 0 amappl13 168 11 0 9 1 0 1 1 0 8 0 amappl12 160 150 0 146 2 1 1 1 0 8 0 amappl11 152 53 0 38 1 0 1 1 0 8 0 amappl10 144 22 0 15 1 0 1 1 0 8 0 amappl9 136 425 0 421 1 0 1 1 0 8 0 amappl8 128 264 0 239 1 0 1 1 0 8 0 amappl7 120 106 0 94 1 0 1 1 0 8 0 amappl6 112 59 0 51 1 0 1 1 0 8 0 amappl5 104 908 0 893 1 0 1 1 0 8 0 amappl4 96 774 0 741 2 1 1 2 0 8 0 amappl3 88 134 0 126 1 0 1 1 0 8 0 amappl2 80 3194 0 3120 3 1 2 3 0 8 0 amappl1 72 21498 0 21044 25 15 10 20 0 8 0 amappl 80 1582 0 1535 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 19 0 8 1 0 1 1 0 8 0 uaddrrnd 24 516 0 498 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 516 0 498 1 0 1 1 0 8 0 vmmpekpl 168 8266 0 8234 2 0 2 2 0 8 0 vmmpepl 168 71034 0 68942 132 34 98 119 0 357 3 vmsppl 368 515 0 498 2 0 2 2 0 8 0 pdppl 4096 1039 0 998 7 1 6 6 0 8 0 pvpl 32 207725 0 187888 191 17 174 181 0 265 11 pmappl 232 515 0 498 3 1 2 2 0 8 0 extentpl 40 46 0 29 1 0 1 1 0 8 0 phpool 112 192 0 11 6 0 6 6 0 8 0