panic(ffffffff821c547b) at panic+0x15c sys/kern/subr_prf.c:207 pool_cache_get(ffffffff82621c18) at pool_cache_get+0x323 pool_cache_item_magic_check sys/kern/subr_pool.c:1789 [inline] pool_cache_get(ffffffff82621c18) at pool_cache_get+0x323 sys/kern/subr_pool.c:1892 pool_get(ffffffff82621c18,2) at pool_get+0x91 sys/kern/subr_pool.c:572 m_copym(fffffd8068cc0100,b00,580,2) at m_copym+0x174 m_get sys/kern/uipc_mbuf.c:250 [inline] m_copym(fffffd8068cc0100,b00,580,2) at m_copym+0x174 sys/kern/uipc_mbuf.c:667 tcp_output(ffff8000009fd540) at tcp_output+0x15ba sys/netinet/tcp_output.c:673 tcp_usrreq(fffffd806e955a88,9,fffffd8068cc0100,0,0,ffff800020aa6288) at tcp_usrreq+0xa55 sosend(fffffd806e955a88,0,ffff800020ac1b48,0,0,80) at sosend+0x671 sys/kern/uipc_socket.c:524 dofilewritev(ffff800020aa6288,4,ffff800020ac1b48,0,ffff800020ac1c30) at dofilewritev+0x1b7 sys/kern/sys_generic.c:364 sys_write(ffff800020aa6288,ffff800020ac1be0,ffff800020ac1c30) at sys_write+0x83 sys/kern/sys_generic.c:284 syscall(ffff800020ac1cb0) at syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:92 [inline] syscall(ffff800020ac1cb0) at syscall+0x4a4 sys/arch/amd64/amd64/trap.c:555 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7f7ffffe14c0, 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 0xfffffd806d549f00+16 0x0!=0x7ffdaa0126a440ab ddb{0}> trace db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:398 panic(ffffffff821c547b) at panic+0x15c sys/kern/subr_prf.c:207 pool_cache_get(ffffffff82621c18) at pool_cache_get+0x323 pool_cache_item_magic_check sys/kern/subr_pool.c:1789 [inline] pool_cache_get(ffffffff82621c18) at pool_cache_get+0x323 sys/kern/subr_pool.c:1892 pool_get(ffffffff82621c18,2) at pool_get+0x91 sys/kern/subr_pool.c:572 m_copym(fffffd8068cc0100,b00,580,2) at m_copym+0x174 m_get sys/kern/uipc_mbuf.c:250 [inline] m_copym(fffffd8068cc0100,b00,580,2) at m_copym+0x174 sys/kern/uipc_mbuf.c:667 tcp_output(ffff8000009fd540) at tcp_output+0x15ba sys/netinet/tcp_output.c:673 tcp_usrreq(fffffd806e955a88,9,fffffd8068cc0100,0,0,ffff800020aa6288) at tcp_usrreq+0xa55 sosend(fffffd806e955a88,0,ffff800020ac1b48,0,0,80) at sosend+0x671 sys/kern/uipc_socket.c:524 dofilewritev(ffff800020aa6288,4,ffff800020ac1b48,0,ffff800020ac1c30) at dofilewritev+0x1b7 sys/kern/sys_generic.c:364 sys_write(ffff800020aa6288,ffff800020ac1be0,ffff800020ac1c30) at sys_write+0x83 sys/kern/sys_generic.c:284 syscall(ffff800020ac1cb0) at syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:92 [inline] syscall(ffff800020ac1cb0) at syscall+0x4a4 sys/arch/amd64/amd64/trap.c:555 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x7f7ffffe14c0, count: -12 ddb{0}> show registers rdi 0 rsi 0x1 rbp 0xffff800020ac14e0 rbx 0xffff800020ac1590 rdx 0xffff800020aa6288 rcx 0 rax 0 r8 0xffffffff81400edf kprintf+0x16f r9 0x1 r10 0x25 r11 0x855c318de96d648 r12 0x3000000008 r13 0xffff800020ac14f0 r14 0x100 r15 0x1 rip 0xffffffff815de968 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff800020ac14d0 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{0}> show proc PROC (sshd) pid=20401 stat=onproc flags process=12 proc=0 pri=51, usrpri=51, nice=20 forw=0xffffffffffffffff, list=0xffff800020aa6c68,0xffff800020aa6ef0 process=0xffff800020aa2728 user=0xffff800020abc000, vmspace=0xfffffd806e798008 estcpu=1, cpticks=3, pctcpu=0.0 user=0, sys=3, intr=0 ddb{0}> ps PID TID PPID UID S FLAGS WAIT COMMAND 83807 332304 98055 0 7 0 syz-executor.1 98435 186835 0 0 3 0x14200 acct acct 98055 484525 58731 0 3 0x82 nanosleep syz-executor.1 59198 13130 58731 0 3 0x82 piperd syz-executor.0 58731 58879 64140 0 3 0x82 thrsleep syz-fuzzer 58731 370288 64140 0 3 0x4000082 nanosleep syz-fuzzer 58731 78757 64140 0 3 0x4000082 thrsleep syz-fuzzer 58731 29197 64140 0 3 0x4000082 thrsleep syz-fuzzer 58731 102450 64140 0 3 0x4000082 thrsleep syz-fuzzer 58731 450450 64140 0 3 0x4000082 thrsleep syz-fuzzer 58731 73154 64140 0 3 0x4000082 thrsleep syz-fuzzer 58731 133708 64140 0 3 0x4000082 nanosleep syz-fuzzer 58731 268068 64140 0 3 0x4000082 thrsleep syz-fuzzer 58731 7414 64140 0 2 0x4000002 syz-fuzzer 64140 204167 98616 0 3 0x10008a pause ksh *98616 20401 89888 0 7 0x12 sshd 96617 134804 1 0 3 0x100083 ttyin getty 89888 9574 1 0 3 0x80 select sshd 48047 397311 94951 74 3 0x100092 bpf pflogd 94951 391338 1 0 3 0x80 netio pflogd 42265 479631 54198 73 3 0x100090 kqread syslogd 54198 498421 1 0 3 0x100082 netio syslogd 12202 160478 1 77 3 0x100090 poll dhclient 88996 43363 1 0 3 0x80 poll dhclient 56835 400685 0 0 2 0x14200 zerothread 68188 420099 0 0 3 0x14200 aiodoned aiodoned 59768 490036 0 0 3 0x14200 syncer update 86506 5069 0 0 3 0x14200 cleaner cleaner 15389 139240 0 0 3 0x14200 reaper reaper 11768 141657 0 0 3 0x14200 pgdaemon pagedaemon 78746 82589 0 0 3 0x14200 bored crynlk 52079 272550 0 0 3 0x14200 bored crypto 52537 474601 0 0 3 0x14200 bored viomb 10445 487031 0 0 3 0x40014200 acpi0 acpi0 37039 117531 0 0 3 0x40014200 idle1 9114 236286 0 0 3 0x14200 bored softnet 69799 503992 0 0 3 0x14200 bored systqmp 85922 231673 0 0 3 0x14200 bored systq 25471 477462 0 0 3 0x40014200 bored softclock 27006 399257 0 0 3 0x40014200 idle0 26856 382187 0 0 3 0x14200 bored smr 1 436410 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 (0xffffffff82658cf0) #0 witness_lock+0x52e sys/kern/subr_witness.c:1163 #1 sleep_setup+0xe9 sys/kern/kern_synch.c:366 #2 msleep+0xe2 sleep_setup_timeout sys/kern/kern_synch.c:405 [inline] #2 msleep+0xe2 sys/kern/kern_synch.c:238 #3 taskq_next_work+0xba sys/kern/kern_task.c:322 #4 taskq_thread+0xe5 sys/kern/kern_task.c:365 #5 proc_trampoline+0x1c Process 98616 (sshd) thread 0xffff800020aa6288 (20401) exclusive rwlock netlock r = 0 (0xffffffff82478d78) #0 witness_lock+0x52e sys/kern/subr_witness.c:1163 #1 solock+0x5a sys/kern/uipc_socket2.c:282 #2 sosend+0x559 sys/kern/uipc_socket.c:512 #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:92 [inline] #5 syscall+0x4a4 sys/arch/amd64/amd64/trap.c:555 #6 Xsyscall+0x128 ddb{0}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim devbuf 9493 6537K 6537K 78643K 10584 0 pcb 13 8K 8K 78643K 21 0 rtable 105 3K 3K 78643K 205 0 ifaddr 44 10K 10K 78643K 47 0 counters 39 33K 33K 78643K 39 0 ioctlops 0 0K 4K 78643K 1469 0 iov 0 0K 8K 78643K 2 0 mount 1 1K 1K 78643K 1 0 vnodes 1217 76K 76K 78643K 1223 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 6 0K 0K 78643K 6 0 dirhash 12 2K 2K 78643K 12 0 ACPI 1810 197K 290K 78643K 12817 0 file desc 5 13K 25K 78643K 42 0 proc 59 63K 95K 78643K 438 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 30 132K 132K 78643K 30 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 107 21K 22K 78643K 1053 0 UVM aobj 6 2K 2K 78643K 6 0 memdesc 1 4K 4K 78643K 1 0 crypto data 1 1K 1K 78643K 1 0 ip6_options 0 0K 0K 78643K 1 0 NDP 6 0K 0K 78643K 10 0 temp 81 3023K 3087K 78643K 3494 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 6 0 0 1 0 1 1 0 8 0 plcache 128 20 0 0 1 0 1 1 0 8 0 rtpcb 80 21 0 19 1 0 1 1 0 8 0 rtentry 112 45 0 1 2 0 2 2 0 8 0 unpcb 120 45 0 35 1 0 1 1 0 8 0 syncache 264 4 0 4 1 1 0 1 0 8 0 tcpqe 32 327 0 327 1 0 1 1 0 8 1 tcpcb 544 12 0 8 1 0 1 1 0 8 0 inpcb 280 49 0 42 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 11 0 0 1 0 1 1 0 8 0 pfstkey 112 11 0 0 1 0 1 1 0 8 0 pfstate 328 11 0 0 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 256 211 0 0 14 0 14 14 0 8 0 art_table 32 212 0 0 2 0 2 2 0 8 0 art_node 16 44 0 4 1 0 1 1 0 8 0 sysvmsgpl 40 24 0 24 1 0 1 1 0 8 1 semapl 112 4 0 0 1 0 1 1 0 8 0 shmpl 112 4 0 0 1 0 1 1 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino1pl 128 1437 0 28 46 0 46 46 0 8 0 ffsino 272 1437 0 28 95 0 95 95 0 8 1 nchpl 144 1677 0 62 61 0 61 61 0 8 0 uvmvnodes 72 1484 0 0 27 0 27 27 0 8 0 vnodes 208 1484 0 0 79 0 79 79 0 8 0 namei 1024 4303 0 4303 2 1 1 1 0 8 1 percpumem 16 30 0 0 1 0 1 1 0 8 0 scxspl 192 4551 0 4549 2 1 1 2 0 8 0 plimitpl 152 19 0 11 1 0 1 1 0 8 0 sigapl 432 241 0 226 3 0 3 3 0 8 1 futexpl 56 251 0 251 1 0 1 1 0 8 1 knotepl 112 53 0 34 1 0 1 1 0 8 0 kqueuepl 104 2 0 0 1 0 1 1 0 8 0 pipepl 160 152 0 133 1 0 1 1 0 8 0 fdescpl 488 242 0 226 3 0 3 3 0 8 0 filepl 152 1231 0 1131 6 1 5 5 0 8 1 lockfpl 104 7 0 6 1 0 1 1 0 8 0 lockfspl 48 4 0 3 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 51 0 42 1 0 1 1 0 8 0 zombiepl 144 226 0 226 2 1 1 1 0 8 1 processpl 904 259 0 226 4 0 4 4 0 8 0 procpl 632 291 0 249 5 0 5 5 0 8 1 sockpl 384 115 0 96 5 1 4 4 0 8 2 mcl64k 65536 1 0 0 1 0 1 1 0 8 0 mcl16k 16384 1 0 0 1 0 1 1 0 8 0 mcl4k 4096 3 0 0 1 0 1 1 0 8 0 mcl2k 2048 179 0 0 22 0 22 22 0 8 0 mtagpl 80 1 0 0 1 0 1 1 0 8 0 mbufpl 256 185 0 0 12 0 12 12 0 8 0 bufpl 280 8325 0 1340 499 0 499 499 0 8 0 anonpl 16 44723 0 26903 90 1 89 89 0 125 16 amapchunkpl 152 1009 0 877 7 0 7 7 0 158 0 amappl16 192 1312 0 337 61 0 61 61 0 8 12 amappl15 184 64 0 59 1 0 1 1 0 8 0 amappl14 176 29 0 26 1 0 1 1 0 8 0 amappl13 168 1 0 0 1 0 1 1 0 8 0 amappl12 160 17 0 15 2 1 1 1 0 8 0 amappl11 152 51 0 36 1 0 1 1 0 8 0 amappl10 144 12 0 8 1 0 1 1 0 8 0 amappl9 136 602 0 599 1 0 1 1 0 8 0 amappl8 128 123 0 99 1 0 1 1 0 8 0 amappl7 120 111 0 99 1 0 1 1 0 8 0 amappl6 112 64 0 55 1 0 1 1 0 8 0 amappl5 104 127 0 113 1 0 1 1 0 8 0 amappl4 96 497 0 465 2 1 1 2 0 8 0 amappl3 88 115 0 107 1 0 1 1 0 8 0 amappl2 80 1014 0 946 3 1 2 3 0 8 0 amappl1 72 15415 0 14977 27 13 14 21 0 8 4 amappl 80 536 0 494 2 0 2 2 0 84 1 dma4096 4096 1 0 1 1 1 0 1 0 8 0 dma1024 1024 1 0 0 1 0 1 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 5 0 0 1 0 1 1 0 8 0 uaddrrnd 24 242 0 226 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 242 0 226 1 0 1 1 0 8 0 vmmpekpl 168 5860 0 5831 2 0 2 2 0 8 0 vmmpepl 168 37974 0 35849 140 6 134 134 0 357 41 vmsppl 368 241 0 226 2 0 2 2 0 8 0 pdppl 4096 491 0 452 7 1 6 6 0 8 1 pvpl 32 139505 0 118604 209 1 208 208 0 265 36 pmappl 232 241 0 226 2 0 2 2 0 8 1 extentpl 40 50 0 32 1 0 1 1 0 8 0 phpool 112 171 0 5 5 0 5 5 0 8 0