panic(ffffffff821cc540) at panic+0x15c sys/kern/subr_prf.c:207 pool_cache_get(ffffffff8264bde0) at pool_cache_get+0x323 pool_cache_item_magic_check sys/kern/subr_pool.c:1781 [inline] pool_cache_get(ffffffff8264bde0) at pool_cache_get+0x323 sys/kern/subr_pool.c:1884 pool_get(ffffffff8264bde0,2) at pool_get+0x91 sys/kern/subr_pool.c:572 m_copym(fffffd8069b60600,154,2dc,2) at m_copym+0x174 m_get sys/kern/uipc_mbuf.c:250 [inline] m_copym(fffffd8069b60600,154,2dc,2) at m_copym+0x174 sys/kern/uipc_mbuf.c:667 tcp_output(ffff800000a04320) at tcp_output+0x15ba sys/netinet/tcp_output.c:673 tcp_usrreq(fffffd806eb00af8,9,fffffd806f34aa00,0,0,ffff800020ae1870) at tcp_usrreq+0xa55 sosend(fffffd806eb00af8,0,ffff800020b03ad8,0,0,80) at sosend+0x671 sys/kern/uipc_socket.c:549 dofilewritev(ffff800020ae1870,4,ffff800020b03ad8,0,ffff800020b03bc0) at dofilewritev+0x1b6 sys/kern/sys_generic.c:364 sys_write(ffff800020ae1870,ffff800020b03b70,ffff800020b03bc0) at sys_write+0x83 sys/kern/sys_generic.c:284 syscall(ffff800020b03c40) at syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:102 [inline] syscall(ffff800020b03c40) at syscall+0x4a4 sys/arch/amd64/amd64/trap.c:570 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7f7ffffeab00, 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 0xfffffd806f34a800+16 0x0!=0xbca5c4a9a0e4f741 ddb{1}> trace db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:398 panic(ffffffff821cc540) at panic+0x15c sys/kern/subr_prf.c:207 pool_cache_get(ffffffff8264bde0) at pool_cache_get+0x323 pool_cache_item_magic_check sys/kern/subr_pool.c:1781 [inline] pool_cache_get(ffffffff8264bde0) at pool_cache_get+0x323 sys/kern/subr_pool.c:1884 pool_get(ffffffff8264bde0,2) at pool_get+0x91 sys/kern/subr_pool.c:572 m_copym(fffffd8069b60600,154,2dc,2) at m_copym+0x174 m_get sys/kern/uipc_mbuf.c:250 [inline] m_copym(fffffd8069b60600,154,2dc,2) at m_copym+0x174 sys/kern/uipc_mbuf.c:667 tcp_output(ffff800000a04320) at tcp_output+0x15ba sys/netinet/tcp_output.c:673 tcp_usrreq(fffffd806eb00af8,9,fffffd806f34aa00,0,0,ffff800020ae1870) at tcp_usrreq+0xa55 sosend(fffffd806eb00af8,0,ffff800020b03ad8,0,0,80) at sosend+0x671 sys/kern/uipc_socket.c:549 dofilewritev(ffff800020ae1870,4,ffff800020b03ad8,0,ffff800020b03bc0) at dofilewritev+0x1b6 sys/kern/sys_generic.c:364 sys_write(ffff800020ae1870,ffff800020b03b70,ffff800020b03bc0) at sys_write+0x83 sys/kern/sys_generic.c:284 syscall(ffff800020b03c40) at syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:102 [inline] syscall(ffff800020b03c40) at syscall+0x4a4 sys/arch/amd64/amd64/trap.c:570 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7f7ffffeab00, count: -12 ddb{1}> show registers rdi 0 rsi 0x1 rbp 0xffff800020b03470 rbx 0xffff800020b03520 rdx 0xffff800020ae1870 rcx 0 rax 0 r8 0xffffffff812ffc6f kprintf+0x16f r9 0x1 r10 0x25 r11 0x6e1ee9f0e0eb21d5 r12 0x3000000008 r13 0xffff800020b03480 r14 0x100 r15 0x1 rip 0xffffffff81ae2228 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff800020b03460 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{1}> show proc PROC (sshd) pid=341154 stat=onproc flags process=12 proc=0 pri=50, usrpri=51, nice=20 forw=0xffffffffffffffff, list=0xffff800020ae09d0,0xffff800020ae0770 process=0xffff800020ad8018 user=0xffff800020afe000, vmspace=0xfffffd806e9252e8 estcpu=1, cpticks=2, pctcpu=0.0 user=0, sys=2, intr=0 ddb{1}> ps PID TID PPID UID S FLAGS WAIT COMMAND 63129 274081 38650 0 2 0 syz-executor.1 63129 286074 38650 0 3 0x4000080 fsleep syz-executor.1 63129 381299 38650 0 7 0x4000000 syz-executor.1 38650 213843 17947 0 2 0x482 syz-executor.1 85816 140097 17947 0 2 0x2 syz-executor.0 17947 452610 69067 0 3 0x82 thrsleep syz-fuzzer 17947 491557 69067 0 2 0x4000482 syz-fuzzer 17947 212357 69067 0 3 0x4000082 thrsleep syz-fuzzer 17947 515698 69067 0 3 0x4000082 thrsleep syz-fuzzer 17947 514606 69067 0 3 0x4000082 thrsleep syz-fuzzer 17947 319692 69067 0 3 0x4000082 kqread syz-fuzzer 17947 191857 69067 0 3 0x4000082 thrsleep syz-fuzzer 17947 481986 69067 0 3 0x4000082 thrsleep syz-fuzzer 17947 148956 69067 0 2 0x4000482 syz-fuzzer 17947 423476 69067 0 3 0x4000082 thrsleep syz-fuzzer 69067 449149 36188 0 3 0x10008a pause ksh *36188 341154 74525 0 7 0x12 sshd 34242 498994 1 0 3 0x100083 ttyin getty 74525 347142 1 0 3 0x80 select sshd 32444 494964 15706 74 3 0x100092 bpf pflogd 15706 235394 1 0 3 0x80 netio pflogd 81086 55378 46118 73 3 0x100090 kqread syslogd 46118 196607 1 0 3 0x100082 netio syslogd 48780 410462 1 77 3 0x100090 poll dhclient 14542 477251 1 0 3 0x80 poll dhclient 36790 34578 0 0 2 0x14200 zerothread 26315 384300 0 0 3 0x14200 aiodoned aiodoned 18957 209891 0 0 3 0x14200 syncer update 48252 140589 0 0 3 0x14200 cleaner cleaner 30902 124639 0 0 3 0x14200 reaper reaper 87787 459269 0 0 3 0x14200 pgdaemon pagedaemon 5460 99297 0 0 3 0x14200 bored crynlk 74516 174686 0 0 3 0x14200 bored crypto 99220 372243 0 0 3 0x40014200 acpi0 acpi0 61732 22665 0 0 3 0x40014200 idle1 8724 397124 0 0 3 0x14200 bored softnet 11647 114142 0 0 3 0x14200 bored systqmp 93669 432731 0 0 3 0x14200 bored systq 32850 516012 0 0 3 0x40014200 bored softclock 30171 464956 0 0 3 0x40014200 idle0 33407 145821 0 0 3 0x14200 bored smr 1 416323 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb{1}> show all locks Process 85816 (syz-executor.0) thread 0xffff800020a7dad8 (140097) exclusive rrwlock inode r = 0 (0xfffffd8079011700) #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+0xf9 sys/kern/vfs_vops.c:615 #4 vn_lock+0x81 sys/kern/vfs_vnops.c:571 #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:1323 #8 ufs_lookup+0x14b7 sys/ufs/ufs/ufs_lookup.c:487 #9 VOP_LOOKUP+0x5b sys/kern/vfs_vops.c:91 #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 (0xfffffd806b44a4d8) #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+0xf9 sys/kern/vfs_vops.c:615 #4 vn_lock+0x81 sys/kern/vfs_vnops.c:571 #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 17947 (syz-fuzzer) thread 0xffff800020a7c008 (423476) exclusive rwlock pipelk r = 0 (0xfffffd807ec22cd0) #0 witness_lock+0x52e sys/kern/subr_witness.c:1164 #1 pipe_read+0x3e sys/kern/sys_pipe.c:396 #2 dofilereadv+0x1a1 sys/kern/sys_generic.c:236 #3 sys_read+0x83 sys/kern/sys_generic.c:156 #4 syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:102 [inline] #4 syscall+0x4a4 sys/arch/amd64/amd64/trap.c:570 #5 Xsyscall+0x128 Process 36188 (sshd) thread 0xffff800020ae1870 (341154) exclusive rwlock netlock r = 0 (0xffffffff824e1c98) #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: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{1}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim devbuf 9490 6531K 6786K 78643K 10668 0 pcb 13 8K 8K 78643K 35 0 rtable 108 4K 4K 78643K 221 0 ifaddr 51 11K 12K 78643K 71 0 counters 43 33K 34K 78643K 49 0 ioctlops 0 0K 4K 78643K 1469 0 iov 0 0K 12K 78643K 9 0 mount 1 1K 1K 78643K 1 0 vnodes 1215 76K 76K 78643K 1245 0 UFS quota 1 32K 32K 78643K 1 0 UFS mount 5 36K 36K 78643K 5 0 shm 2 1K 1K 78643K 2 0 VM map 2 1K 1K 78643K 2 0 sem 7 0K 0K 78643K 8 0 dirhash 12 2K 2K 78643K 12 0 ACPI 1809 196K 290K 78643K 12766 0 file desc 5 13K 25K 78643K 72 0 proc 60 63K 95K 78643K 439 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 2 0 in_multi 40 2K 2K 78643K 44 0 ether_multi 1 0K 0K 78643K 2 0 mrt 0 0K 0K 78643K 3 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 207 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 112 22K 22K 78643K 1164 0 UVM aobj 4 2K 2K 78643K 4 0 memdesc 1 4K 4K 78643K 1 0 crypto data 1 1K 1K 78643K 1 0 NDP 7 0K 0K 78643K 14 0 temp 80 3010K 3074K 78643K 2205 0 kqueue 3 4K 6K 78643K 4 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 6 0 0 1 0 1 1 0 8 0 plcache 128 20 0 0 1 0 1 1 0 8 0 rtpcb 80 19 0 17 1 0 1 1 0 8 0 rtentry 112 46 0 2 2 0 2 2 0 8 0 unpcb 120 40 0 30 1 0 1 1 0 8 0 syncache 264 4 0 4 1 1 0 1 0 8 0 tcpqe 32 976 0 976 1 0 1 1 0 8 1 tcpcb 544 24 0 20 1 0 1 1 0 8 0 inpcb 280 98 0 91 2 0 2 2 0 8 1 rttmr 72 1 0 1 1 0 1 1 0 8 1 nd6 48 4 0 0 1 0 1 1 0 8 0 ppxss 1128 2 0 2 1 0 1 1 0 8 1 pffrag 232 2 0 2 1 0 1 1 0 482 1 pffrnode 88 2 0 2 1 0 1 1 0 8 1 pffrent 40 6 0 6 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 13 0 0 1 0 1 1 0 8 0 pfstkey 112 13 0 0 1 0 1 1 0 8 0 pfstate 328 13 0 0 2 0 2 2 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 256 235 0 22 15 0 15 15 0 8 1 art_table 32 236 0 22 2 0 2 2 0 8 0 art_node 16 45 0 5 1 0 1 1 0 8 0 sysvmsgpl 40 17 0 4 1 0 1 1 0 8 0 semupl 112 1 0 1 1 0 1 1 0 8 1 semapl 112 6 0 1 1 0 1 1 0 8 0 shmpl 112 2 0 0 1 0 1 1 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino1pl 128 1484 0 78 46 0 46 46 0 8 0 ffsino 272 1484 0 78 95 0 95 95 0 8 0 nchpl 144 1764 0 145 61 0 61 61 0 8 0 uvmvnodes 72 1546 0 0 29 0 29 29 0 8 0 vnodes 208 1546 0 0 82 0 82 82 0 8 0 namei 1024 4623 0 4623 2 1 1 1 0 8 1 percpumem 16 35 0 3 1 0 1 1 0 8 0 scxspl 192 5288 0 5288 7 1 6 6 0 8 6 plimitpl 152 17 0 9 1 0 1 1 0 8 0 sigapl 432 271 0 256 3 0 3 3 0 8 1 futexpl 56 655 0 654 1 0 1 1 0 8 0 knotepl 112 55 0 36 1 0 1 1 0 8 0 kqueuepl 104 8 0 6 1 0 1 1 0 8 0 pipelkpl 48 115 0 105 1 0 1 1 0 8 0 pipepl 120 230 0 211 1 0 1 1 0 8 0 fdescpl 496 272 0 256 3 0 3 3 0 8 0 filepl 152 1471 0 1371 6 1 5 5 0 8 1 lockfpl 104 19 0 18 1 0 1 1 0 8 0 lockfspl 48 8 0 7 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 64 0 55 1 0 1 1 0 8 0 zombiepl 144 256 0 256 2 1 1 1 0 8 1 processpl 960 287 0 256 6 1 5 5 0 8 0 procpl 624 391 0 349 4 0 4 4 0 8 0 sockpl 400 157 0 138 5 1 4 4 0 8 2 mcl64k 65536 4 0 0 1 0 1 1 0 8 0 mcl12k 12288 2 0 0 1 0 1 1 0 8 0 mcl9k 9216 1 0 0 1 0 1 1 0 8 0 mcl8k 8192 2 0 0 1 0 1 1 0 8 0 mcl4k 4096 3 0 0 1 0 1 1 0 8 0 mcl2k 2048 182 0 0 22 0 22 22 0 8 0 mtagpl 80 10 0 0 1 0 1 1 0 8 0 mbufpl 256 223 0 0 14 0 14 14 0 8 0 bufpl 280 4187 0 192 286 0 286 286 0 8 0 anonpl 16 40302 0 24798 64 1 63 63 0 125 0 amapchunkpl 152 1342 0 1192 9 0 9 9 0 158 1 amappl16 192 1039 0 218 42 0 42 42 0 8 0 amappl15 184 93 0 86 1 0 1 1 0 8 0 amappl14 176 28 0 26 1 0 1 1 0 8 0 amappl12 160 19 0 16 2 1 1 1 0 8 0 amappl11 152 54 0 38 1 0 1 1 0 8 0 amappl10 144 36 0 29 1 0 1 1 0 8 0 amappl9 136 602 0 599 1 0 1 1 0 8 0 amappl8 128 129 0 105 1 0 1 1 0 8 0 amappl7 120 123 0 112 1 0 1 1 0 8 0 amappl6 112 57 0 51 1 0 1 1 0 8 0 amappl5 104 130 0 116 1 0 1 1 0 8 0 amappl4 96 528 0 496 2 1 1 2 0 8 0 amappl3 88 118 0 111 1 0 1 1 0 8 0 amappl2 80 1286 0 1211 3 1 2 3 0 8 0 amappl1 72 16118 0 15665 25 14 11 21 0 8 1 amappl 80 644 0 597 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 3 0 0 1 0 1 1 0 8 0 uaddrrnd 24 272 0 256 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 272 0 256 1 0 1 1 0 8 0 vmmpekpl 168 6232 0 6199 2 0 2 2 0 8 0 vmmpepl 168 40799 0 38801 126 6 120 120 0 357 30 vmsppl 368 271 0 256 2 0 2 2 0 8 0 pdppl 4096 551 0 512 7 1 6 6 0 8 0 pvpl 32 140701 0 122043 154 1 153 153 0 265 2 pmappl 232 271 0 256 2 0 2 2 0 8 1 extentpl 40 46 0 29 1 0 1 1 0 8 0 phpool 112 178 0 6 5 0 5 5 0 8 0