panic(ffffffff821cdab9) at panic+0x15c sys/kern/subr_prf.c:207 pool_cache_get(ffffffff826394b0) at pool_cache_get+0x323 pool_cache_item_magic_check sys/kern/subr_pool.c:1781 [inline] pool_cache_get(ffffffff826394b0) at pool_cache_get+0x323 sys/kern/subr_pool.c:1884 pool_get(ffffffff826394b0,2) 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(fffffd806eaeac88,9,fffffd806f1ec600,0,0,ffff800020ae1d50) at tcp_usrreq+0xa55 sosend(fffffd806eaeac88,0,ffff800020ac3508,0,0,80) at sosend+0x671 sys/kern/uipc_socket.c:549 dofilewritev(ffff800020ae1d50,4,ffff800020ac3508,0,ffff800020ac35f0) at dofilewritev+0x1b7 sys/kern/sys_generic.c:364 sys_write(ffff800020ae1d50,ffff800020ac35a0,ffff800020ac35f0) at sys_write+0x83 sys/kern/sys_generic.c:284 syscall(ffff800020ac3670) at syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:102 [inline] syscall(ffff800020ac3670) at syscall+0x4a4 sys/arch/amd64/amd64/trap.c:570 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7f7ffffdc210, 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 0xfffffd806d8dcd00+16 0x0!=0xa754215cca50ada7 ddb{0}> trace db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:398 panic(ffffffff821cdab9) at panic+0x15c sys/kern/subr_prf.c:207 pool_cache_get(ffffffff826394b0) at pool_cache_get+0x323 pool_cache_item_magic_check sys/kern/subr_pool.c:1781 [inline] pool_cache_get(ffffffff826394b0) at pool_cache_get+0x323 sys/kern/subr_pool.c:1884 pool_get(ffffffff826394b0,2) 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(fffffd806eaeac88,9,fffffd806f1ec600,0,0,ffff800020ae1d50) at tcp_usrreq+0xa55 sosend(fffffd806eaeac88,0,ffff800020ac3508,0,0,80) at sosend+0x671 sys/kern/uipc_socket.c:549 dofilewritev(ffff800020ae1d50,4,ffff800020ac3508,0,ffff800020ac35f0) at dofilewritev+0x1b7 sys/kern/sys_generic.c:364 sys_write(ffff800020ae1d50,ffff800020ac35a0,ffff800020ac35f0) at sys_write+0x83 sys/kern/sys_generic.c:284 syscall(ffff800020ac3670) at syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:102 [inline] syscall(ffff800020ac3670) at syscall+0x4a4 sys/arch/amd64/amd64/trap.c:570 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7f7ffffdc210, count: -12 ddb{0}> show registers rdi 0 rsi 0x1 rbp 0xffff800020ac2f00 rbx 0xffff800020ac2fb0 rdx 0xffff800020ae1d50 rcx 0 rax 0 r8 0xffffffff82046aaf kprintf+0x16f r9 0x1 r10 0x25 r11 0xe78b6cb480dddef8 r12 0x3000000008 r13 0xffff800020ac2f10 r14 0x100 r15 0x1 rip 0xffffffff813899a8 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff800020ac2ef0 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{0}> show proc PROC (sshd) pid=420276 stat=onproc flags process=12 proc=0 pri=24, usrpri=50, nice=20 forw=0xffffffffffffffff, list=0xffff800020ae0c40,0xffff800020ae0ec0 process=0xffff800020ad8b58 user=0xffff800020abe000, vmspace=0xfffffd806e9102e8 estcpu=0, cpticks=2, pctcpu=0.0 user=0, sys=2, intr=0 ddb{0}> ps PID TID PPID UID S FLAGS WAIT COMMAND 89402 198754 51644 0 2 0 syz-executor.0 89402 421213 51644 0 3 0x4000080 fsleep syz-executor.0 89402 507457 51644 0 7 0x4000000 syz-executor.0 96547 19438 22833 0 3 0x2 biowait syz-executor.1 51644 320157 22833 0 3 0x82 nanosleep syz-executor.0 22833 523081 39902 0 3 0x82 thrsleep syz-fuzzer 22833 470547 39902 0 3 0x4000082 nanosleep syz-fuzzer 22833 125940 39902 0 3 0x4000082 thrsleep syz-fuzzer 22833 114769 39902 0 3 0x4000082 thrsleep syz-fuzzer 22833 137049 39902 0 3 0x4000082 thrsleep syz-fuzzer 22833 287361 39902 0 3 0x4000082 kqread syz-fuzzer 22833 495173 39902 0 3 0x4000082 thrsleep syz-fuzzer 22833 253174 39902 0 3 0x4000082 nanosleep syz-fuzzer 22833 320883 39902 0 3 0x4000082 thrsleep syz-fuzzer 22833 417131 39902 0 3 0x4000082 thrsleep syz-fuzzer 22833 443568 39902 0 3 0x4000082 thrsleep syz-fuzzer 39902 210780 28176 0 3 0x10008a pause ksh *28176 420276 50716 0 7 0x12 sshd 49171 468741 1 0 3 0x100083 ttyin getty 50716 469789 1 0 3 0x80 select sshd 83346 134974 30624 74 3 0x100092 bpf pflogd 30624 264066 1 0 3 0x80 netio pflogd 14883 449058 82541 73 3 0x100090 kqread syslogd 82541 169325 1 0 3 0x100082 netio syslogd 64170 438145 1 77 3 0x100090 poll dhclient 19023 435437 1 0 3 0x80 poll dhclient 38394 419258 0 0 3 0x14200 pgzero zerothread 82528 298568 0 0 3 0x14200 aiodoned aiodoned 15659 68744 0 0 3 0x14200 syncer update 17746 316972 0 0 3 0x14200 cleaner cleaner 9084 322607 0 0 3 0x14200 reaper reaper 14133 129616 0 0 3 0x14200 pgdaemon pagedaemon 27270 205127 0 0 3 0x14200 bored crynlk 26978 316475 0 0 3 0x14200 bored crypto 77454 510327 0 0 3 0x40014200 acpi0 acpi0 68747 7671 0 0 3 0x40014200 idle1 52584 198310 0 0 3 0x14200 bored softnet 77239 14831 0 0 3 0x14200 bored systqmp 88238 327046 0 0 3 0x14200 bored systq 99810 234547 0 0 3 0x40014200 bored softclock 33408 49962 0 0 3 0x40014200 idle0 13003 289084 0 0 3 0x14200 bored smr 1 500679 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb{0}> show all locks CPU 1: exclusive sched_lock &sched_lock r = 0 (0xffffffff826566d8) #0 witness_lock+0x52e sys/kern/subr_witness.c:1164 #1 sleep_setup+0xe9 sys/kern/kern_synch.c:393 #2 tsleep+0xe6 sleep_setup_timeout sys/kern/kern_synch.c:432 [inline] #2 tsleep+0xe6 sys/kern/kern_synch.c:151 #3 kqueue_scan+0x326 sys/kern/kern_event.c:870 #4 sys_kevent+0x492 sys/kern/kern_event.c:604 #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 Process 96547 (syz-executor.1) thread 0xffff800020ac9608 (19438) exclusive rrwlock inode r = 0 (0xfffffd80671cda30) #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 (0xfffffd80671cdd60) #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 cache_lookup+0x2bb sys/kern/vfs_cache.c:224 #7 ufs_lookup+0x1bc sys/ufs/ufs/ufs_lookup.c:162 #8 VOP_LOOKUP+0x5b sys/kern/vfs_vops.c:91 #9 vfs_lookup+0x7a6 sys/kern/vfs_lookup.c:568 #10 namei+0x63c sys/kern/vfs_lookup.c:249 #11 dounlinkat+0x99 sys/kern/vfs_syscalls.c:1860 #12 syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:102 [inline] #12 syscall+0x4a4 sys/arch/amd64/amd64/trap.c:570 #13 Xsyscall+0x128 Process 28176 (sshd) thread 0xffff800020ae1d50 (420276) exclusive rwlock netlock r = 0 (0xffffffff8247dc38) #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 9478 6401K 6721K 78643K 10704 0 pcb 13 8K 8K 78643K 25 0 rtable 105 3K 3K 78643K 246 0 ifaddr 50 11K 11K 78643K 75 0 counters 43 33K 34K 78643K 51 0 ioctlops 0 0K 4K 78643K 1471 0 iov 0 0K 12K 78643K 26 0 mount 1 1K 1K 78643K 1 0 vnodes 1219 77K 77K 78643K 1255 0 UFS quota 1 32K 32K 78643K 1 0 UFS mount 5 36K 36K 78643K 5 0 shm 2 1K 5K 78643K 3 0 VM map 2 1K 1K 78643K 2 0 sem 12 0K 1K 78643K 30 0 dirhash 12 2K 2K 78643K 12 0 ACPI 1809 196K 290K 78643K 12766 0 file desc 5 13K 25K 78643K 81 0 proc 61 63K 95K 78643K 448 0 subproc 32 2K 2K 78643K 34 0 NFS srvsock 1 0K 0K 78643K 1 0 NFS daemon 1 16K 16K 78643K 1 0 in_multi 33 2K 2K 78643K 33 0 ether_multi 1 0K 0K 78643K 1 0 ISOFS mount 1 32K 32K 78643K 1 0 MSDOSFS mount 1 16K 16K 78643K 1 0 ttys 31 148K 148K 78643K 31 0 exec 0 0K 1K 78643K 209 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 104 21K 22K 78643K 1209 0 UVM aobj 14 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 2 0 NDP 7 0K 0K 78643K 15 0 temp 87 3011K 3075K 78643K 4057 0 kqueue 3 4K 4K 78643K 3 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 2 1 0 1 1 0 8 0 plcache 128 20 0 0 1 0 1 1 0 8 0 rtpcb 80 25 0 23 1 0 1 1 0 8 0 rtentry 112 51 0 7 2 0 2 2 0 8 0 unpcb 120 173 0 163 1 0 1 1 0 8 0 syncache 264 4 0 4 1 1 0 1 0 8 0 tcpqe 32 9 0 9 1 1 0 1 0 8 0 tcpcb 544 28 0 24 1 0 1 1 0 8 0 inpcb 280 91 0 83 1 0 1 1 0 8 0 nd6 48 4 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 12 0 1 1 0 1 1 0 8 0 pfstkey 112 12 0 1 1 0 1 1 0 8 0 pfstate 328 12 0 1 1 0 1 1 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 256 220 0 6 14 0 14 14 0 8 0 art_table 32 221 0 6 2 0 2 2 0 8 0 art_node 16 50 0 10 1 0 1 1 0 8 0 sysvmsgpl 40 12 0 6 1 0 1 1 0 8 0 semupl 112 3 0 3 1 0 1 1 0 8 1 semapl 112 24 0 14 1 0 1 1 0 8 0 shmpl 112 12 0 0 1 0 1 1 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino1pl 128 1496 0 88 46 0 46 46 0 8 0 ffsino 272 1496 0 88 95 0 95 95 0 8 0 nchpl 144 1806 0 188 61 0 61 61 0 8 0 uvmvnodes 72 1570 0 0 29 0 29 29 0 8 0 vnodes 208 1570 0 0 83 0 83 83 0 8 0 namei 1024 4693 0 4693 1 0 1 1 0 8 1 percpumem 16 36 0 4 1 0 1 1 0 8 0 scxspl 192 5400 0 5399 8 1 7 7 0 8 6 plimitpl 152 15 0 7 1 0 1 1 0 8 0 sigapl 432 280 0 265 3 0 3 3 0 8 1 futexpl 56 1012 0 1011 1 0 1 1 0 8 0 knotepl 112 53 0 34 1 0 1 1 0 8 0 kqueuepl 104 14 0 12 1 0 1 1 0 8 0 pipelkpl 48 86 0 76 1 0 1 1 0 8 0 pipepl 120 172 0 153 2 0 2 2 0 8 1 fdescpl 496 281 0 265 3 0 3 3 0 8 0 filepl 152 1617 0 1515 6 0 6 6 0 8 2 lockfpl 104 16 0 15 1 0 1 1 0 8 0 lockfspl 48 7 0 6 1 0 1 1 0 8 0 sessionpl 112 18 0 7 1 0 1 1 0 8 0 pgrppl 48 20 0 9 1 0 1 1 0 8 0 ucredpl 96 69 0 60 1 0 1 1 0 8 0 zombiepl 144 265 0 265 1 0 1 1 0 8 1 processpl 960 296 0 265 5 0 5 5 0 8 0 procpl 624 439 0 396 5 0 5 5 0 8 1 sockpl 400 289 0 269 4 0 4 4 0 8 1 mcl64k 65536 9 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 mcl8k 8192 3 0 0 1 0 1 1 0 8 0 mcl4k 4096 3 0 0 1 0 1 1 0 8 0 mcl2k2 2112 2 0 0 1 0 1 1 0 8 0 mcl2k 2048 152 0 0 18 0 18 18 0 8 0 mtagpl 80 5 0 0 1 0 1 1 0 8 0 mbufpl 256 170 0 0 10 0 10 10 0 8 0 bufpl 280 4217 0 191 288 0 288 288 0 8 0 anonpl 16 46703 0 29888 82 1 81 81 0 125 13 amapchunkpl 152 1276 0 1141 8 0 8 8 0 158 1 amappl16 192 1427 0 506 56 0 56 56 0 8 9 amappl15 184 58 0 55 1 0 1 1 0 8 0 amappl14 176 56 0 52 1 0 1 1 0 8 0 amappl13 168 20 0 19 1 0 1 1 0 8 0 amappl12 160 15 0 13 1 0 1 1 0 8 0 amappl11 152 56 0 40 1 0 1 1 0 8 0 amappl10 144 14 0 11 1 0 1 1 0 8 0 amappl9 136 600 0 597 1 0 1 1 0 8 0 amappl8 128 139 0 113 2 0 2 2 0 8 0 amappl7 120 103 0 92 1 0 1 1 0 8 0 amappl6 112 59 0 51 1 0 1 1 0 8 0 amappl5 104 136 0 122 1 0 1 1 0 8 0 amappl4 96 535 0 501 2 1 1 2 0 8 0 amappl3 88 143 0 135 1 0 1 1 0 8 0 amappl2 80 1367 0 1290 3 1 2 3 0 8 0 amappl1 72 16329 0 15869 25 13 12 20 0 8 2 amappl 80 691 0 648 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 0 1 0 1 1 0 8 0 uaddrrnd 24 281 0 265 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 281 0 265 1 0 1 1 0 8 0 vmmpekpl 168 6233 0 6206 2 0 2 2 0 8 0 vmmpepl 168 42655 0 40539 118 7 111 112 0 357 19 vmsppl 368 280 0 265 2 0 2 2 0 8 0 pdppl 4096 569 0 530 6 0 6 6 0 8 1 pvpl 32 152159 0 132194 197 0 197 197 0 265 35 pmappl 232 280 0 265 2 0 2 2 0 8 1 extentpl 40 46 0 29 1 0 1 1 0 8 0 phpool 112 169 0 3 5 0 5 5 0 8 0