panic(ffffffff821f3b71) at panic+0x15c sys/kern/subr_prf.c:207 pool_cache_get(ffffffff82649140) at pool_cache_get+0x323 pool_cache_item_magic_check sys/kern/subr_pool.c:1781 [inline] pool_cache_get(ffffffff82649140) at pool_cache_get+0x323 sys/kern/subr_pool.c:1884 pool_get(ffffffff82649140,2) 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(ffff800000a0b980) at tcp_output+0x14e6 tcp_usrreq(fffffd806eb6f7d8,9,fffffd806d9a1200,0,0,ffff800020ade280) at tcp_usrreq+0xa55 sosend(fffffd806eb6f7d8,0,ffff800020a91b18,0,0,80) at sosend+0x671 sys/kern/uipc_socket.c:549 dofilewritev(ffff800020ade280,4,ffff800020a91b18,0,ffff800020a91c00) at dofilewritev+0x1b6 sys/kern/sys_generic.c:365 sys_write(ffff800020ade280,ffff800020a91bb0,ffff800020a91c00) at sys_write+0x83 sys/kern/sys_generic.c:285 syscall(ffff800020a91c80) at syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:102 [inline] syscall(ffff800020a91c80) at syscall+0x4a4 sys/arch/amd64/amd64/trap.c:570 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7f7ffffb9890, 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 0xfffffd806d9a1a00+16 0x0!=0x9c9e0c84dbafae3b ddb{1}> trace db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:398 panic(ffffffff821f3b71) at panic+0x15c sys/kern/subr_prf.c:207 pool_cache_get(ffffffff82649140) at pool_cache_get+0x323 pool_cache_item_magic_check sys/kern/subr_pool.c:1781 [inline] pool_cache_get(ffffffff82649140) at pool_cache_get+0x323 sys/kern/subr_pool.c:1884 pool_get(ffffffff82649140,2) 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(ffff800000a0b980) at tcp_output+0x14e6 tcp_usrreq(fffffd806eb6f7d8,9,fffffd806d9a1200,0,0,ffff800020ade280) at tcp_usrreq+0xa55 sosend(fffffd806eb6f7d8,0,ffff800020a91b18,0,0,80) at sosend+0x671 sys/kern/uipc_socket.c:549 dofilewritev(ffff800020ade280,4,ffff800020a91b18,0,ffff800020a91c00) at dofilewritev+0x1b6 sys/kern/sys_generic.c:365 sys_write(ffff800020ade280,ffff800020a91bb0,ffff800020a91c00) at sys_write+0x83 sys/kern/sys_generic.c:285 syscall(ffff800020a91c80) at syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:102 [inline] syscall(ffff800020a91c80) at syscall+0x4a4 sys/arch/amd64/amd64/trap.c:570 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7f7ffffb9890, count: -12 ddb{1}> show registers rdi 0 rsi 0x1 rbp 0xffff800020a91510 rbx 0xffff800020a915c0 rdx 0xffff800020ade280 rcx 0 rax 0 r8 0xffffffff814bd98f kprintf+0x16f r9 0x1 r10 0x25 r11 0xa798d58527283518 r12 0x3000000008 r13 0xffff800020a91520 r14 0x100 r15 0x1 rip 0xffffffff81b979c8 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff800020a91500 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{1}> show proc PROC (sshd) pid=258914 stat=onproc flags process=12 proc=0 pri=50, usrpri=51, nice=20 forw=0xffffffffffffffff, list=0xffff800020ade4f0,0xffff800020adf3a0 process=0xffff800020ac8018 user=0xffff800020a8c000, vmspace=0xfffffd806e99f458 estcpu=1, cpticks=3, pctcpu=0.0 user=0, sys=2, intr=0 ddb{1}> ps PID TID PPID UID S FLAGS WAIT COMMAND 66044 249007 63002 0 7 0 syz-executor.0 47354 263059 0 0 3 0x14200 bored sosplice 96110 110054 89405 0 2 0x2 syz-executor.1 63002 400456 89405 0 2 0x482 syz-executor.0 89405 334891 33468 0 3 0x82 thrsleep syz-fuzzer 89405 27040 33468 0 2 0x4000482 syz-fuzzer 89405 197167 33468 0 2 0x4000482 syz-fuzzer 89405 110072 33468 0 3 0x4000082 thrsleep syz-fuzzer 89405 270431 33468 0 3 0x4000082 kqread syz-fuzzer 89405 52655 33468 0 3 0x4000082 thrsleep syz-fuzzer 89405 514573 33468 0 3 0x4000082 thrsleep syz-fuzzer 89405 101118 33468 0 3 0x4000082 thrsleep syz-fuzzer 89405 5192 33468 0 3 0x4000082 thrsleep syz-fuzzer 89405 448150 33468 0 3 0x4000082 thrsleep syz-fuzzer 33468 451029 69725 0 3 0x10008a pause ksh *69725 258914 86506 0 7 0x12 sshd 98526 144246 1 0 3 0x100083 ttyin getty 86506 270027 1 0 3 0x80 select sshd 89166 410291 66756 74 3 0x100092 bpf pflogd 66756 335166 1 0 3 0x80 netio pflogd 27977 367613 42050 73 3 0x100090 kqread syslogd 42050 189611 1 0 3 0x100082 netio syslogd 63847 177986 1 77 3 0x100090 poll dhclient 9364 476907 1 0 3 0x80 poll dhclient 53849 378701 0 0 3 0x14200 bored smr 51286 3968 0 0 2 0x14200 zerothread 1384 455245 0 0 3 0x14200 aiodoned aiodoned 76827 218700 0 0 3 0x14200 syncer update 13307 172034 0 0 3 0x14200 cleaner cleaner 60068 500954 0 0 3 0x14200 reaper reaper 69389 139101 0 0 3 0x14200 pgdaemon pagedaemon 16370 238431 0 0 3 0x14200 bored crynlk 79413 303196 0 0 3 0x14200 bored crypto 68435 169149 0 0 3 0x40014200 acpi0 acpi0 16050 339684 0 0 3 0x40014200 idle1 22355 488682 0 0 3 0x14200 bored softnet 31601 8603 0 0 3 0x14200 bored systqmp 1624 56278 0 0 3 0x14200 bored systq 17933 104181 0 0 3 0x40014200 bored softclock 9829 93365 0 0 3 0x40014200 idle0 1 515167 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb{1}> show all locks Process 96110 (syz-executor.1) thread 0xffff800020ad7d58 (110054) exclusive rrwlock inode r = 0 (0xfffffd80728544e8) #0 witness_lock+0x4c5 sys/kern/subr_witness.c:1164 #1 rw_enter+0x453 sys/kern/kern_rwlock.c:311 #2 rrw_enter+0x88 sys/kern/kern_rwlock.c:462 #3 ufs_ihashins+0x45 sys/ufs/ufs/ufs_ihash.c:140 #4 ffs_vget+0x13e sys/ufs/ffs/ffs_vfsops.c:1358 #5 ffs_inode_alloc+0x1cf sys/ufs/ffs/ffs_alloc.c:392 #6 ufs_mkdir+0xf4 sys/ufs/ufs/ufs_vnops.c:1162 #7 VOP_MKDIR+0xc6 sys/kern/vfs_vops.c:449 #8 domkdirat+0x121 sys/kern/vfs_syscalls.c:3051 #9 syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:102 [inline] #9 syscall+0x4a4 sys/arch/amd64/amd64/trap.c:570 #10 Xsyscall+0x128 exclusive rrwlock inode r = 0 (0xfffffd806b43a1a8) #0 witness_lock+0x4c5 sys/kern/subr_witness.c:1164 #1 rw_enter+0x453 sys/kern/kern_rwlock.c:311 #2 rrw_enter+0x88 sys/kern/kern_rwlock.c:462 #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 domkdirat+0x75 sys/kern/vfs_syscalls.c:3036 #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 89405 (syz-fuzzer) thread 0xffff800020a6c278 (5192) exclusive kernel_lock &kernel_lock r = 0 (0xffffffff8266f3c0) #0 witness_lock+0x4c5 sys/kern/subr_witness.c:1164 #1 uvm_map_inentry+0xbe sys/uvm/uvm_map.c:1890 #2 syscall+0x397 mi_syscall sys/sys/syscall_mi.h:81 [inline] #2 syscall+0x397 sys/arch/amd64/amd64/trap.c:570 #3 Xsyscall+0x128 Process 69725 (sshd) thread 0xffff800020ade280 (258914) exclusive rwlock netlock r = 0 (0xffffffff82519508) #0 witness_lock+0x4c5 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 9488 6404K 7370K 78643K 10840 0 pcb 13 8K 8K 78643K 33 0 rtable 105 3K 3K 78643K 211 0 ifaddr 55 12K 12K 78643K 70 0 counters 43 33K 34K 78643K 45 0 ioctlops 0 0K 4K 78643K 1481 0 iov 0 0K 12K 78643K 16 0 mount 1 1K 1K 78643K 1 0 vnodes 1222 77K 77K 78643K 1280 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 12 0K 0K 78643K 20 0 dirhash 12 2K 2K 78643K 12 0 ACPI 1809 196K 290K 78643K 12766 0 file desc 5 13K 25K 78643K 94 0 proc 61 63K 95K 78643K 440 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 59 0 in_multi 40 2K 2K 78643K 53 0 ether_multi 1 0K 0K 78643K 6 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 217 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 97 53K 53K 78643K 1215 0 UVM aobj 2 2K 2K 78643K 2 0 memdesc 1 4K 4K 78643K 1 0 crypto data 1 1K 1K 78643K 1 0 ip6_options 0 0K 0K 78643K 8 0 NDP 8 0K 0K 78643K 13 0 temp 81 3037K 3101K 78643K 2470 0 kqueue 3 4K 4K 78643K 3 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 23 0 21 1 0 1 1 0 8 0 rtentry 112 45 0 1 2 0 2 2 0 8 0 unpcb 120 43 0 33 1 0 1 1 0 8 0 syncache 264 7 0 7 2 1 1 1 0 8 1 tcpqe 32 26 0 26 1 0 1 1 0 8 1 tcpcb 544 63 0 58 1 0 1 1 0 8 0 inpcb 280 169 0 161 2 0 2 2 0 8 1 nd6 48 6 0 0 1 0 1 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 20 0 0 1 0 1 1 0 8 0 pfstkey 112 20 0 0 1 0 1 1 0 8 0 pfstate 328 20 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 256 189 0 0 12 0 12 12 0 8 0 art_table 32 190 0 0 2 0 2 2 0 8 0 art_node 16 44 0 4 1 0 1 1 0 8 0 sysvmsgpl 40 8 0 4 1 0 1 1 0 8 0 semapl 112 16 0 6 1 0 1 1 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino1pl 128 1498 0 90 46 0 46 46 0 8 0 ffsino 272 1498 0 90 94 0 94 94 0 8 0 nchpl 144 1803 0 188 61 0 61 61 0 8 0 uvmvnodes 72 1596 0 0 30 0 30 30 0 8 0 vnodes 208 1596 0 0 84 0 84 84 0 8 0 namei 1024 4654 0 4653 1 0 1 1 0 8 0 percpumem 16 33 0 1 1 0 1 1 0 8 0 vcpupl 1984 4 0 0 1 0 1 1 0 8 0 vmpool 560 4 0 0 1 0 1 1 0 8 0 scxspl 192 5186 0 5186 2 1 1 2 0 8 1 plimitpl 152 21 0 13 1 0 1 1 0 8 0 sigapl 424 310 0 278 4 0 4 4 0 8 0 futexpl 56 1090 0 1090 1 0 1 1 0 8 1 knotepl 112 53 0 34 1 0 1 1 0 8 0 kqueuepl 144 4 0 2 1 0 1 1 0 8 0 pipelkpl 48 92 0 82 1 0 1 1 0 8 0 pipepl 120 184 0 165 1 0 1 1 0 8 0 fdescpl 496 294 0 278 3 0 3 3 0 8 0 filepl 152 1528 0 1428 5 0 5 5 0 8 1 lockfpl 104 73 0 72 1 0 1 1 0 8 0 lockfspl 48 34 0 33 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 84 0 75 1 0 1 1 0 8 0 zombiepl 144 278 0 278 1 0 1 1 0 8 1 processpl 984 310 0 278 5 0 5 5 0 8 0 procpl 624 466 0 425 4 0 4 4 0 8 0 sosppl 128 1 0 0 1 0 1 1 0 8 0 sockpl 400 235 0 214 3 0 3 3 0 8 0 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 1 0 0 1 0 1 1 0 8 0 mcl4k 4096 2 0 0 1 0 1 1 0 8 0 mcl2k 2048 164 0 0 20 0 20 20 0 8 0 mtagpl 80 27 0 0 1 0 1 1 0 8 0 mbufpl 256 171 0 0 11 0 11 11 0 8 0 bufpl 280 4123 0 169 283 0 283 283 0 8 0 anonpl 16 39706 0 26231 56 1 55 55 0 124 0 amapchunkpl 152 1397 0 1265 7 0 7 7 0 158 0 amappl16 192 1105 0 384 37 0 37 37 0 8 0 amappl15 184 1 0 0 1 0 1 1 0 8 0 amappl14 176 61 0 59 3 2 1 1 0 8 0 amappl13 168 27 0 25 1 0 1 1 0 8 0 amappl12 160 7 0 6 1 0 1 1 0 8 0 amappl11 152 73 0 55 1 0 1 1 0 8 0 amappl10 144 16 0 12 1 0 1 1 0 8 0 amappl9 136 389 0 386 1 0 1 1 0 8 0 amappl8 128 293 0 281 1 0 1 1 0 8 0 amappl7 120 117 0 106 1 0 1 1 0 8 0 amappl6 112 21 0 19 1 0 1 1 0 8 0 amappl5 104 135 0 119 1 0 1 1 0 8 0 amappl4 96 571 0 534 2 1 1 2 0 8 0 amappl3 88 165 0 158 1 0 1 1 0 8 0 amappl2 80 1416 0 1353 3 1 2 3 0 8 0 amappl1 72 16444 0 16020 26 12 14 20 0 8 5 amappl 80 719 0 673 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 1 0 0 1 0 1 1 0 8 0 uaddrrnd 24 298 0 278 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 298 0 278 1 0 1 1 0 8 0 vmmpekpl 168 6267 0 6233 2 0 2 2 0 8 0 vmmpepl 168 42516 0 40696 105 4 101 101 0 357 20 vmsppl 368 297 0 278 2 0 2 2 0 8 0 pdppl 4096 604 0 560 6 0 6 6 0 8 0 pvpl 32 141766 0 125245 138 0 138 138 0 265 2 pmappl 232 297 0 278 2 0 2 2 0 8 0 extentpl 40 46 0 29 1 0 1 1 0 8 0 phpool 112 165 0 3 5 0 5 5 0 8 0