panic(ffffffff821eb9b9) at panic+0x15c sys/kern/subr_prf.c:207 pool_cache_get(ffffffff82677198) at pool_cache_get+0x323 pool_cache_item_magic_check sys/kern/subr_pool.c:1781 [inline] pool_cache_get(ffffffff82677198) at pool_cache_get+0x323 sys/kern/subr_pool.c:1884 pool_get(ffffffff82677198,2) 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(ffff800000a05540) at tcp_output+0x14e6 tcp_usrreq(fffffd806eb69968,9,fffffd80639e4a00,0,0,ffff800020ae1d50) at tcp_usrreq+0xa55 sosend(fffffd806eb69968,0,ffff800020b031c8,0,0,80) at sosend+0x671 sys/kern/uipc_socket.c:549 dofilewritev(ffff800020ae1d50,4,ffff800020b031c8,0,ffff800020b032b0) at dofilewritev+0x1b6 sys/kern/sys_generic.c:365 sys_write(ffff800020ae1d50,ffff800020b03260,ffff800020b032b0) at sys_write+0x83 sys/kern/sys_generic.c:285 syscall(ffff800020b03330) at syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:102 [inline] syscall(ffff800020b03330) at syscall+0x4a4 sys/arch/amd64/amd64/trap.c:570 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7f7ffffd90f0, 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{1}> ddb{1}> set $lines = 0 ddb{1}> set $maxwidth = 0 ddb{1}> show panic pool_cache_item_magic_check: mbufpl cpu free list modified: item addr 0xfffffd806f1c6300+16 0x0!=0x38437fa3aeec39d6 ddb{1}> trace db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:398 panic(ffffffff821eb9b9) at panic+0x15c sys/kern/subr_prf.c:207 pool_cache_get(ffffffff82677198) at pool_cache_get+0x323 pool_cache_item_magic_check sys/kern/subr_pool.c:1781 [inline] pool_cache_get(ffffffff82677198) at pool_cache_get+0x323 sys/kern/subr_pool.c:1884 pool_get(ffffffff82677198,2) 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(ffff800000a05540) at tcp_output+0x14e6 tcp_usrreq(fffffd806eb69968,9,fffffd80639e4a00,0,0,ffff800020ae1d50) at tcp_usrreq+0xa55 sosend(fffffd806eb69968,0,ffff800020b031c8,0,0,80) at sosend+0x671 sys/kern/uipc_socket.c:549 dofilewritev(ffff800020ae1d50,4,ffff800020b031c8,0,ffff800020b032b0) at dofilewritev+0x1b6 sys/kern/sys_generic.c:365 sys_write(ffff800020ae1d50,ffff800020b03260,ffff800020b032b0) at sys_write+0x83 sys/kern/sys_generic.c:285 syscall(ffff800020b03330) at syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:102 [inline] syscall(ffff800020b03330) at syscall+0x4a4 sys/arch/amd64/amd64/trap.c:570 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7f7ffffd90f0, count: -12 ddb{1}> show registers rdi 0 rsi 0x1 rbp 0xffff800020b02bc0 rbx 0xffff800020b02c70 rdx 0xffff800020ae1d50 rcx 0 rax 0 r8 0xffffffff814a3d9f kprintf+0x16f r9 0x1 r10 0x25 r11 0x5b8144f2ed8dc086 r12 0x3000000008 r13 0xffff800020b02bd0 r14 0x100 r15 0x1 rip 0xffffffff8153b258 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff800020b02bb0 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{1}> show proc PROC (sshd) pid=398168 stat=onproc flags process=12 proc=0 pri=50, usrpri=51, nice=20 forw=0xffffffffffffffff, list=0xffff800020ae0280,0xffff800020ae1130 process=0xffff800020ad8798 user=0xffff800020afe000, vmspace=0xfffffd806e999a18 estcpu=1, cpticks=2, pctcpu=0.0 user=0, sys=2, intr=0 ddb{1}> ps PID TID PPID UID S FLAGS WAIT COMMAND 53956 401175 52364 0 7 0 syz-executor.0 76494 8978 0 0 3 0x14200 bored sosplice 2291 272789 10190 0 2 0x2 syz-executor.1 52364 46827 10190 0 2 0x482 syz-executor.0 10190 147049 34499 0 3 0x82 thrsleep syz-fuzzer 10190 143349 34499 0 2 0x4000482 syz-fuzzer 10190 434571 34499 0 3 0x4000082 thrsleep syz-fuzzer 10190 269021 34499 0 3 0x4000082 thrsleep syz-fuzzer 10190 480980 34499 0 3 0x4000082 thrsleep syz-fuzzer 10190 274235 34499 0 3 0x4000082 kqread syz-fuzzer 10190 511262 34499 0 3 0x4000082 thrsleep syz-fuzzer 10190 84818 34499 0 2 0x4000482 syz-fuzzer 10190 374125 34499 0 3 0x4000082 thrsleep syz-fuzzer 10190 457772 34499 0 3 0x4000082 thrsleep syz-fuzzer 34499 327754 93891 0 3 0x10008a pause ksh *93891 398168 83250 0 7 0x12 sshd 86826 313084 1 0 3 0x100083 ttyin getty 83250 17176 1 0 3 0x80 select sshd 26205 383634 95752 74 3 0x100092 bpf pflogd 95752 183317 1 0 3 0x80 netio pflogd 85840 52769 29798 73 3 0x100090 kqread syslogd 29798 180671 1 0 3 0x100082 netio syslogd 32988 67617 1 77 3 0x100090 poll dhclient 73720 177892 1 0 3 0x80 poll dhclient 8605 78749 0 0 3 0x14200 pgzero zerothread 74041 417652 0 0 3 0x14200 aiodoned aiodoned 93169 378136 0 0 3 0x14200 syncer update 24746 117752 0 0 3 0x14200 cleaner cleaner 22581 510101 0 0 3 0x14200 reaper reaper 50304 270177 0 0 3 0x14200 pgdaemon pagedaemon 25622 502138 0 0 3 0x14200 bored crynlk 32559 452401 0 0 3 0x14200 bored crypto 50564 217647 0 0 3 0x40014200 acpi0 acpi0 7243 312575 0 0 3 0x40014200 idle1 64505 381379 0 0 3 0x14200 bored softnet 74936 215480 0 0 3 0x14200 bored systqmp 25972 356919 0 0 3 0x14200 bored systq 26134 105595 0 0 3 0x40014200 bored softclock 42846 229700 0 0 3 0x40014200 idle0 69287 34146 0 0 3 0x14200 bored smr 1 46909 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb{1}> show all locks Process 2291 (syz-executor.1) thread 0xffff800020ac3878 (272789) exclusive rrwlock inode r = 0 (0xfffffd80637d4e70) #0 witness_lock+0x52e sys/kern/subr_witness.c:1164 #1 rw_enter+0x453 sys/kern/kern_rwlock.c:309 #2 rrw_enter+0x88 sys/kern/kern_rwlock.c:453 #3 VOP_LOCK+0x4b sys/kern/vfs_vops.c:602 #4 vn_lock+0x81 sys/kern/vfs_vnops.c:575 #5 vget+0x1c8 sys/kern/vfs_subr.c:671 #6 ufs_ihashget+0x141 sys/ufs/ufs/ufs_ihash.c:119 #7 ffs_vget+0x74 sys/ufs/ffs/ffs_vfsops.c:1329 #8 ufs_lookup+0x14b7 sys/ufs/ufs/ufs_lookup.c:487 #9 VOP_LOOKUP+0x5b sys/kern/vfs_vops.c:90 #10 vfs_lookup+0x7a6 sys/kern/vfs_lookup.c:568 #11 namei+0x63c sys/kern/vfs_lookup.c:249 #12 dounlinkat+0x99 sys/kern/vfs_syscalls.c:1860 #13 syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:102 [inline] #13 syscall+0x4a4 sys/arch/amd64/amd64/trap.c:570 #14 Xsyscall+0x128 exclusive rrwlock inode r = 0 (0xfffffd806b4524d8) #0 witness_lock+0x52e sys/kern/subr_witness.c:1164 #1 rw_enter+0x453 sys/kern/kern_rwlock.c:309 #2 rrw_enter+0x88 sys/kern/kern_rwlock.c:453 #3 VOP_LOCK+0x4b sys/kern/vfs_vops.c:602 #4 vn_lock+0x81 sys/kern/vfs_vnops.c:575 #5 vfs_lookup+0xe6 sys/kern/vfs_lookup.c:419 #6 namei+0x63c sys/kern/vfs_lookup.c:249 #7 dounlinkat+0x99 sys/kern/vfs_syscalls.c:1860 #8 syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:102 [inline] #8 syscall+0x4a4 sys/arch/amd64/amd64/trap.c:570 #9 Xsyscall+0x128 Process 93891 (sshd) thread 0xffff800020ae1d50 (398168) exclusive rwlock netlock r = 0 (0xffffffff825135f8) #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+0x1b6 sys/kern/sys_generic.c:365 #4 sys_write+0x83 sys/kern/sys_generic.c:285 #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{1}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim devbuf 9495 6407K 6665K 78643K 10788 0 pcb 13 8K 8K 78643K 74 0 rtable 110 4K 4K 78643K 274 0 ifaddr 59 12K 13K 78643K 81 0 counters 43 33K 34K 78643K 49 0 ioctlops 0 0K 4K 78643K 1474 0 iov 0 0K 24K 78643K 36 0 mount 1 1K 1K 78643K 1 0 vnodes 1224 77K 77K 78643K 1284 0 UFS quota 1 32K 32K 78643K 1 0 UFS mount 5 36K 36K 78643K 5 0 shm 2 1K 5K 78643K 6 0 VM map 2 1K 1K 78643K 2 0 sem 12 0K 0K 78643K 116 0 dirhash 12 2K 2K 78643K 12 0 ACPI 1809 196K 290K 78643K 12766 0 file desc 5 13K 25K 78643K 165 0 proc 63 63K 83K 78643K 442 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 46 0 in_multi 36 2K 2K 78643K 90 0 ether_multi 1 0K 0K 78643K 12 0 ISOFS mount 1 32K 32K 78643K 1 0 MSDOSFS mount 1 16K 16K 78643K 1 0 ttys 37 175K 175K 78643K 37 0 exec 0 0K 1K 78643K 227 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 110 22K 24K 78643K 1474 0 UVM aobj 11 2K 2K 78643K 14 0 memdesc 1 4K 4K 78643K 1 0 crypto data 1 1K 1K 78643K 1 0 ip6_options 0 0K 0K 78643K 48 0 NDP 9 0K 0K 78643K 19 0 temp 112 3020K 3084K 78643K 8990 0 kqueue 3 4K 9K 78643K 17 0 SYN cache 2 16K 16K 78643K 2 0 ddb{1}> show all pools Name Size Requests Fail Releases Pgreq Pgrel Npage Hiwat Minpg Maxpg Idle arp 64 7 0 0 1 0 1 1 0 8 0 plcache 128 20 0 0 1 0 1 1 0 8 0 rtpcb 80 37 0 35 1 0 1 1 0 8 0 rtentry 112 63 0 18 2 0 2 2 0 8 0 unpcb 120 147 0 137 1 0 1 1 0 8 0 syncache 264 4 0 4 1 1 0 1 0 8 0 tcpqe 32 41 0 41 1 1 0 1 0 8 0 tcpcb 544 129 0 125 1 0 1 1 0 8 0 inpcb 280 374 0 367 2 0 2 2 0 8 1 nd6 48 10 0 5 1 0 1 1 0 8 0 pkpcb 40 1 0 1 1 0 1 1 0 8 1 ppxss 1128 1 0 1 1 0 1 1 0 8 1 pffrag 232 3 0 3 1 0 1 1 0 482 1 pffrnode 88 3 0 3 1 0 1 1 0 8 1 pffrent 40 135 0 135 1 0 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 34 0 2 1 0 1 1 0 8 0 pfstkey 112 34 0 2 1 0 1 1 0 8 0 pfstate 328 34 0 2 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 256 290 0 93 13 0 13 13 0 8 0 art_table 32 291 0 93 2 0 2 2 0 8 0 art_node 16 62 0 20 1 0 1 1 0 8 0 sysvmsgpl 40 29 0 16 1 0 1 1 0 8 0 semapl 112 114 0 104 1 0 1 1 0 8 0 shmpl 112 12 0 3 1 0 1 1 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino1pl 128 1604 0 195 46 0 46 46 0 8 0 ffsino 272 1604 0 195 95 0 95 95 0 8 0 nchpl 144 2094 0 477 61 0 61 61 0 8 0 uvmvnodes 72 1697 0 0 31 0 31 31 0 8 0 vnodes 208 1697 0 0 90 0 90 90 0 8 0 namei 1024 5663 0 5663 1 0 1 1 0 8 1 percpumem 16 35 0 3 1 0 1 1 0 8 0 scxspl 192 6441 0 6441 4 1 3 3 0 8 3 plimitpl 152 27 0 19 1 0 1 1 0 8 0 sigapl 424 381 0 349 4 0 4 4 0 8 0 futexpl 56 3716 0 3716 1 0 1 1 0 8 1 knotepl 112 72 0 53 1 0 1 1 0 8 0 kqueuepl 144 42 0 40 1 0 1 1 0 8 0 pipelkpl 48 109 0 99 1 0 1 1 0 8 0 pipepl 120 218 0 199 1 0 1 1 0 8 0 fdescpl 496 365 0 349 3 0 3 3 0 8 0 filepl 152 2576 0 2476 6 0 6 6 0 8 2 lockfpl 104 51 0 50 1 0 1 1 0 8 0 lockfspl 48 15 0 14 1 0 1 1 0 8 0 sessionpl 112 18 0 7 1 0 1 1 0 8 0 pgrppl 48 18 0 7 1 0 1 1 0 8 0 ucredpl 96 173 0 164 1 0 1 1 0 8 0 zombiepl 144 349 0 349 1 0 1 1 0 8 1 processpl 960 381 0 349 5 0 5 5 0 8 0 procpl 624 718 0 677 5 0 5 5 0 8 1 sosppl 128 8 0 8 1 0 1 1 0 8 1 sockpl 400 583 0 564 5 0 5 5 0 8 3 mcl64k 65536 11 0 0 2 0 2 2 0 8 0 mcl16k 16384 1 0 0 1 0 1 1 0 8 0 mcl12k 12288 2 0 0 1 0 1 1 0 8 0 mcl9k 9216 2 0 0 1 0 1 1 0 8 0 mcl8k 8192 3 0 0 1 0 1 1 0 8 0 mcl4k 4096 4 0 0 1 0 1 1 0 8 0 mcl2k 2048 151 0 0 18 0 18 18 0 8 0 mtagpl 80 13 0 0 1 0 1 1 0 8 0 mbufpl 256 306 0 0 19 0 19 19 0 8 0 bufpl 280 4552 0 174 313 0 313 313 0 8 0 anonpl 16 49311 0 32629 71 1 70 70 0 124 2 amapchunkpl 152 1738 0 1604 8 1 7 8 0 158 0 amappl16 192 1651 0 742 48 0 48 48 0 8 2 amappl15 184 1 0 0 1 0 1 1 0 8 0 amappl14 176 73 0 71 2 1 1 1 0 8 0 amappl13 168 25 0 24 1 0 1 1 0 8 0 amappl12 160 70 0 66 1 0 1 1 0 8 0 amappl11 152 73 0 55 1 0 1 1 0 8 0 amappl10 144 18 0 13 1 0 1 1 0 8 0 amappl9 136 388 0 385 1 0 1 1 0 8 0 amappl8 128 323 0 296 1 0 1 1 0 8 0 amappl7 120 122 0 109 1 0 1 1 0 8 0 amappl6 112 28 0 22 1 0 1 1 0 8 0 amappl5 104 269 0 253 1 0 1 1 0 8 0 amappl4 96 505 0 470 2 1 1 2 0 8 0 amappl3 88 113 0 107 1 0 1 1 0 8 0 amappl2 80 2054 0 1991 3 1 2 3 0 8 0 amappl1 72 18203 0 17777 25 15 10 20 0 8 0 amappl 80 963 0 920 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 13 0 3 1 0 1 1 0 8 0 uaddrrnd 24 365 0 349 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 365 0 349 1 0 1 1 0 8 0 vmmpekpl 168 6905 0 6870 2 0 2 2 0 8 0 vmmpepl 168 51680 0 49656 125 10 115 118 0 357 23 vmsppl 368 364 0 349 2 0 2 2 0 8 0 pdppl 4096 737 0 698 6 0 6 6 0 8 0 pvpl 32 165653 0 145909 170 0 170 170 0 265 8 pmappl 232 364 0 349 2 1 1 2 0 8 0 extentpl 40 46 0 29 1 0 1 1 0 8 0 phpool 112 178 0 3 5 0 5 5 0 8 0