panic() at panic+0x15c sys/kern/subr_prf.c:207 pool_cache_get(ffffffff82664cb8) at pool_cache_get+0x323 pool_cache_item_magic_check sys/kern/subr_pool.c:1789 [inline] pool_cache_get(ffffffff82664cb8) at pool_cache_get+0x323 sys/kern/subr_pool.c:1892 pool_get() at pool_get+0x91 sys/kern/subr_pool.c:572 m_copym(fffffd807b805100,4394,5a0,2) at m_copym+0x174 m_get sys/kern/uipc_mbuf.c:250 [inline] m_copym(fffffd807b805100,4394,5a0,2) at m_copym+0x174 sys/kern/uipc_mbuf.c:667 ip_fragment(fffffd807b805100,ffff8000001732a8,5b4) at ip_fragment+0x324 ip_output(fffffd807b805100,0,fffffd806f6d82a0,0,0,fffffd806f6d8230) at ip_output+0xfc1 sys/netinet/ip_output.c:501 udp_output(fffffd806f6d8230,fffffd807b805100,0,0) at udp_output+0x5af sys/netinet/udp_usrreq.c:1004 sosend(fffffd806168caf0,0,ffff800023b8d3c0,0,0,0) at sosend+0x645 sys/kern/uipc_socket.c:524 sendit(ffff800020abf650,8,ffff800023b8d4a0,0,ffff800023b8d580) at sendit+0x52b sys/kern/uipc_syscalls.c:662 sys_sendto(ffff800020abf650,ffff800023b8d538,ffff800023b8d580) at sys_sendto+0x80 sys/kern/uipc_syscalls.c:527 syscall(ffff800023b8d600) at syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:92 [inline] syscall(ffff800023b8d600) at syscall+0x4a4 sys/arch/amd64/amd64/trap.c:555 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x6c6f7ef30, count: 2 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 0xfffffd806699f000+16 0x0!=0x5fbefbb542d3a316 ddb{1}> trace db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:398 panic() at panic+0x15c sys/kern/subr_prf.c:207 pool_cache_get(ffffffff82664cb8) at pool_cache_get+0x323 pool_cache_item_magic_check sys/kern/subr_pool.c:1789 [inline] pool_cache_get(ffffffff82664cb8) at pool_cache_get+0x323 sys/kern/subr_pool.c:1892 pool_get() at pool_get+0x91 sys/kern/subr_pool.c:572 m_copym(fffffd807b805100,4394,5a0,2) at m_copym+0x174 m_get sys/kern/uipc_mbuf.c:250 [inline] m_copym(fffffd807b805100,4394,5a0,2) at m_copym+0x174 sys/kern/uipc_mbuf.c:667 ip_fragment(fffffd807b805100,ffff8000001732a8,5b4) at ip_fragment+0x324 ip_output(fffffd807b805100,0,fffffd806f6d82a0,0,0,fffffd806f6d8230) at ip_output+0xfc1 sys/netinet/ip_output.c:501 udp_output(fffffd806f6d8230,fffffd807b805100,0,0) at udp_output+0x5af sys/netinet/udp_usrreq.c:1004 sosend(fffffd806168caf0,0,ffff800023b8d3c0,0,0,0) at sosend+0x645 sys/kern/uipc_socket.c:524 sendit(ffff800020abf650,8,ffff800023b8d4a0,0,ffff800023b8d580) at sendit+0x52b sys/kern/uipc_syscalls.c:662 sys_sendto(ffff800020abf650,ffff800023b8d538,ffff800023b8d580) at sys_sendto+0x80 sys/kern/uipc_syscalls.c:527 syscall(ffff800023b8d600) at syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:92 [inline] syscall(ffff800023b8d600) at syscall+0x4a4 sys/arch/amd64/amd64/trap.c:555 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x6c6f7ef30, count: -13 ddb{1}> show registers rdi 0xffffffff81372a17 db_enter+0x17 rsi 0x7577 __ALIGN_SIZE+0x6577 rbp 0xffff800023b8cdd0 rbx 0xffff800023b8ce80 rdx 0x7578 __ALIGN_SIZE+0x6578 rcx 0xffff800023982000 rax 0xffff800023982000 r8 0xffffffff81cadc2f kprintf+0x16f r9 0x1 r10 0x25 r11 0xcca6c816a43303b7 r12 0x3000000008 r13 0xffff800023b8cde0 r14 0x100 r15 0x1 rip 0xffffffff81372a18 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff800023b8cdc0 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{1}> show proc PROC (syz-executor.0) pid=263557 stat=onproc flags process=0 proc=4000000 pri=86, usrpri=86, nice=20 forw=0xffffffffffffffff, list=0xffff800020abe508,0xffffffff8267ba78 process=0xffff800020adc700 user=0xffff800023b88000, vmspace=0xfffffd807f008b80 estcpu=36, cpticks=1, pctcpu=0.0 user=0, sys=1, intr=0 ddb{1}> ps PID TID PPID UID S FLAGS WAIT COMMAND 32510 257309 33307 0 2 0 syz-executor.0 32510 146617 33307 0 3 0x4000080 kqread syz-executor.0 *32510 263557 33307 0 7 0x4000000 syz-executor.0 14618 161875 20778 0 3 0x90 nanosleep syz-executor.1 14618 28647 20778 0 2 0x4000010 syz-executor.1 14618 174017 20778 0 3 0x4000090 fsleep syz-executor.1 33307 412556 82332 0 7 0x482 syz-executor.0 20778 436839 82332 0 3 0x82 nanosleep syz-executor.1 19195 437191 0 0 3 0x14200 acct acct 553 274615 0 0 3 0x14200 bored sosplice 82332 298399 42997 0 3 0x82 thrsleep syz-fuzzer 82332 523243 42997 0 3 0x4000082 thrsleep syz-fuzzer 82332 472346 42997 0 3 0x4000082 thrsleep syz-fuzzer 82332 248761 42997 0 3 0x4000082 kqread syz-fuzzer 82332 86128 42997 0 3 0x4000082 thrsleep syz-fuzzer 82332 240172 42997 0 3 0x4000082 thrsleep syz-fuzzer 82332 462065 42997 0 3 0x4000082 thrsleep syz-fuzzer 82332 518694 42997 0 3 0x4000082 thrsleep syz-fuzzer 82332 215160 42997 0 3 0x4000082 thrsleep syz-fuzzer 82332 453702 42997 0 3 0x4000082 thrsleep syz-fuzzer 42997 515142 97140 0 3 0x10008a pause ksh 97140 235086 83765 0 3 0x92 select sshd 64642 196266 1 0 3 0x100083 ttyin getty 83765 342803 1 0 3 0x80 select sshd 32538 283307 50325 74 3 0x100092 bpf pflogd 50325 479 1 0 3 0x80 netio pflogd 37893 420485 30634 73 3 0x100090 kqread syslogd 30634 29685 1 0 3 0x100082 netio syslogd 68606 371793 1 77 3 0x100090 poll dhclient 45299 516733 1 0 3 0x80 poll dhclient 52270 372798 0 0 3 0x14200 pgzero zerothread 58727 169427 0 0 3 0x14200 aiodoned aiodoned 4999 19402 0 0 3 0x14200 syncer update 4122 248764 0 0 3 0x14200 cleaner cleaner 44283 97988 0 0 3 0x14200 reaper reaper 99176 41717 0 0 3 0x14200 pgdaemon pagedaemon 41184 75272 0 0 3 0x14200 bored crynlk 39064 4582 0 0 3 0x14200 bored crypto 40249 148013 0 0 3 0x40014200 acpi0 acpi0 27354 34040 0 0 3 0x40014200 idle1 10625 103990 0 0 3 0x14200 bored softnet 39874 387348 0 0 3 0x14200 bored systqmp 43988 120608 0 0 3 0x14200 bored systq 39734 125628 0 0 3 0x40014200 bored softclock 48035 457773 0 0 3 0x40014200 idle0 840 133664 0 0 3 0x14200 bored smr 1 350203 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb{1}> show all locks Process 32510 (syz-executor.0) thread 0xffff800020abf650 (263557) exclusive rwlock netlock r = 0 (0xffffffff824b84d8) #0 witness_lock+0x52e sys/kern/subr_witness.c:1163 #1 solock+0x5a sys/kern/uipc_socket2.c:282 #2 sosend+0x51b sys/kern/uipc_socket.c:512 #3 sendit+0x52b sys/kern/uipc_syscalls.c:662 #4 sys_sendto+0x80 sys/kern/uipc_syscalls.c:527 #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 Process 14618 (syz-executor.1) thread 0xffff800020abe018 (28647) exclusive rrwlock inode r = 0 (0xfffffd80691d72b8) #0 witness_lock+0x52e sys/kern/subr_witness.c:1163 #1 rw_enter+0x447 sys/kern/kern_rwlock.c:306 #2 rrw_enter+0x4f sys/kern/kern_rwlock.c:435 #3 VOP_LOCK+0xf0 sys/kern/vfs_vops.c:615 #4 vn_lock+0x81 sys/kern/vfs_vnops.c:571 #5 vn_write+0x11b sys/kern/vfs_vnops.c:411 #6 dofilewritev+0x1b7 sys/kern/sys_generic.c:364 #7 sys_pwritev+0xb8 sys/kern/vfs_syscalls.c:3269 #8 syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:92 [inline] #8 syscall+0x4a4 sys/arch/amd64/amd64/trap.c:555 #9 Xsyscall+0x128 ddb{1}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim Kern Lim devbuf 9567 6461K 8156K 78643K 14454 0 0 pcb 13 8K 9K 78643K 468 0 0 rtable 86 4K 5K 78643K 1076 0 0 ifaddr 143 21K 22K 78643K 385 0 0 counters 39 33K 33K 78643K 39 0 0 ioctlops 0 0K 4K 78643K 1537 0 0 iov 1 12K 48K 78643K 390 0 0 mount 1 1K 1K 78643K 1 0 0 vnodes 1234 78K 78K 78643K 2681 0 0 UFS quota 1 32K 32K 78643K 1 0 0 UFS mount 5 36K 36K 78643K 5 0 0 shm 2 1K 5K 78643K 32 0 0 VM map 11 5K 6K 78643K 29 0 0 sem 12 0K 1K 78643K 589 0 0 dirhash 12 2K 2K 78643K 12 0 0 ACPI 1809 196K 290K 78643K 12766 0 0 file desc 6 17K 25K 78643K 1582 0 0 sigio 0 0K 0K 78643K 51 0 0 proc 62 63K 95K 78643K 918 0 0 subproc 32 2K 2K 78643K 170 0 0 NFS srvsock 1 0K 0K 78643K 1 0 0 NFS daemon 1 16K 16K 78643K 1 0 0 ip_moptions 0 0K 1K 78643K 232 0 0 in_multi 91 5K 5K 78643K 283 0 0 ether_multi 1 0K 0K 78643K 28 0 0 mrt 1 0K 0K 78643K 25 0 0 ISOFS mount 1 32K 32K 78643K 1 0 0 MSDOSFS mount 1 16K 16K 78643K 1 0 0 ttys 60 265K 265K 78643K 60 0 0 exec 0 0K 1K 78643K 490 0 0 pagedep 1 8K 8K 78643K 1 0 0 inodedep 1 32K 32K 78643K 1 0 0 newblk 1 0K 0K 78643K 1 0 0 VM swap 7 26K 26K 78643K 7 0 0 UVM amap 138 104K 108K 78643K 6507 0 0 UVM aobj 130 8K 8K 78643K 132 0 0 memdesc 1 4K 4K 78643K 1 0 0 crypto data 1 1K 1K 78643K 1 0 0 ip6_options 0 0K 1K 78643K 430 0 0 NDP 18 0K 0K 78643K 89 0 0 temp 161 3557K 4191K 78643K 32885 0 0 kqueue 0 0K 0K 78643K 22 0 0 SYN cache 2 16K 16K 78643K 2 0 0 ddb{1}> show all pools Name Size Requests Fail Releases Pgreq Pgrel Npage Hiwat Minpg Maxpg Idle arp 64 46 0 43 1 0 1 1 0 8 0 plcache 128 20 0 0 1 0 1 1 0 8 0 rtpcb 80 173 0 171 1 0 1 1 0 8 0 rtentry 112 205 0 175 2 0 2 2 0 8 0 unpcb 120 1046 0 1035 1 0 1 1 0 8 0 syncache 264 11 0 11 4 3 1 1 0 8 1 tcpqe 32 312 0 312 4 3 1 1 0 8 1 tcpcb 544 912 0 907 8 6 2 4 0 8 1 ipq 40 1 0 1 1 0 1 1 0 8 1 ipqe 40 2 0 2 1 0 1 1 0 8 1 inpcb 280 2899 0 2889 9 6 3 4 0 8 2 rttmr 72 8 0 8 5 4 1 1 0 8 1 nd6 48 25 0 24 1 0 1 1 0 8 0 pkpcb 40 4 0 4 2 2 0 1 0 8 0 ppxss 1128 30 0 30 4 3 1 1 0 8 1 pffrag 232 40 0 40 5 4 1 1 0 482 1 pffrnode 88 40 0 40 5 4 1 1 0 8 1 pffrent 40 1524 0 1524 5 4 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 24 148 0 96 1 0 1 1 0 8 0 pfstkey 112 148 0 96 3 0 3 3 0 8 0 pfstate 328 148 0 96 7 0 7 7 0 8 0 pfrule 1360 21 0 16 2 1 1 2 0 8 0 art_heap8 4096 2 0 0 2 0 2 2 0 8 0 art_heap4 256 830 0 654 24 9 15 15 0 8 4 art_table 32 832 0 654 2 0 2 2 0 8 0 art_node 16 202 0 174 1 0 1 1 0 8 0 sysvmsgpl 40 44 0 28 1 0 1 1 0 8 0 semapl 112 581 0 571 1 0 1 1 0 8 0 shmpl 112 130 0 2 4 0 4 4 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino1pl 128 3821 0 2413 46 0 46 46 0 8 0 ffsino 272 3821 0 2413 95 0 95 95 0 8 0 nchpl 144 7137 0 6685 61 42 19 61 0 8 0 uvmvnodes 72 4962 0 0 91 0 91 91 0 8 0 vnodes 208 4962 0 0 262 0 262 262 0 8 0 namei 1024 23446 0 23446 2 1 1 1 0 8 1 percpumem 16 30 0 0 1 0 1 1 0 8 0 vcpupl 1984 9 0 0 2 0 2 2 0 8 0 vmpool 552 27 0 18 2 1 1 1 0 8 0 scsiplug 64 1 0 1 1 1 0 1 0 8 0 scxspl 192 18789 0 18789 14 13 1 5 0 8 1 plimitpl 152 153 0 145 1 0 1 1 0 8 0 sigapl 432 1756 0 1740 3 1 2 3 0 8 0 futexpl 56 41199 0 41198 2 1 1 1 0 8 0 knotepl 112 368 0 349 1 0 1 1 0 8 0 kqueuepl 104 527 0 524 1 0 1 1 0 8 0 pipepl 160 1222 0 1203 5 3 2 2 0 8 1 fdescpl 488 1757 0 1740 3 0 3 3 0 8 0 filepl 152 17051 0 16944 14 8 6 8 0 8 1 lockfpl 104 572 0 570 1 0 1 1 0 8 0 lockfspl 48 204 0 202 1 0 1 1 0 8 0 sessionpl 112 26 0 15 1 0 1 1 0 8 0 pgrppl 48 38 0 27 1 0 1 1 0 8 0 ucredpl 96 1787 0 1777 1 0 1 1 0 8 0 zombiepl 144 1740 0 1740 1 0 1 1 0 8 1 processpl 896 1774 0 1740 4 0 4 4 0 8 0 procpl 632 5196 0 5149 6 1 5 5 0 8 1 srpgc 64 18 0 18 5 4 1 1 0 8 1 sosppl 128 68 0 68 6 5 1 1 0 8 1 sockpl 384 4154 0 4131 15 10 5 7 0 8 2 mcl64k 65536 20 0 0 3 0 3 3 0 8 0 mcl16k 16384 15 0 0 2 0 2 2 0 8 0 mcl12k 12288 17 0 0 2 0 2 2 0 8 0 mcl9k 9216 14 0 0 1 0 1 1 0 8 0 mcl8k 8192 17 0 0 3 0 3 3 0 8 0 mcl4k 4096 17 0 0 3 0 3 3 0 8 0 mcl2k2 2112 3 0 0 1 0 1 1 0 8 0 mcl2k 2048 237 0 0 29 0 29 29 0 8 0 mtagpl 80 50 0 0 1 0 1 1 0 8 0 mbufpl 256 510 0 0 28 0 28 28 0 8 0 bufpl 256 10032 0 2974 442 0 442 442 0 8 0 anonpl 16 224675 0 202306 140 34 106 106 0 124 14 amapchunkpl 152 12892 0 12728 31 21 10 14 0 158 2 amappl16 192 8907 0 7650 98 27 71 76 0 8 8 amappl15 184 8 0 8 1 1 0 1 0 8 0 amappl14 176 228 0 219 1 0 1 1 0 8 0 amappl13 168 145 0 145 2 2 0 1 0 8 0 amappl12 160 352 0 350 2 1 1 1 0 8 0 amappl11 152 420 0 405 1 0 1 1 0 8 0 amappl10 144 154 0 149 1 0 1 1 0 8 0 amappl9 136 1081 0 1075 1 0 1 1 0 8 0 amappl8 128 648 0 609 2 0 2 2 0 8 0 amappl7 120 209 0 201 1 0 1 1 0 8 0 amappl6 112 392 0 381 1 0 1 1 0 8 0 amappl5 104 573 0 558 1 0 1 1 0 8 0 amappl4 96 1864 0 1832 1 0 1 1 0 8 0 amappl3 88 677 0 669 1 0 1 1 0 8 0 amappl2 80 12671 0 12589 3 1 2 3 0 8 0 amappl1 72 48922 0 48455 26 16 10 20 0 8 0 amappl 80 5633 0 5578 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 64 131 0 2 3 0 3 3 0 8 0 uaddrrnd 24 1784 0 1740 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 1784 0 1740 1 0 1 1 0 8 0 vmmpekpl 168 17783 0 17746 2 0 2 2 0 8 0 vmmpepl 168 229074 0 226498 205 54 151 160 0 357 38 vmsppl 368 1756 0 1740 2 0 2 2 0 8 0 pdppl 4096 3575 0 3525 7 0 7 7 0 8 0 pvpl 32 592160 0 566868 285 48 237 237 0 265 32 pmappl 232 1783 0 1758 3 1 2 2 0 8 0 extentpl 40 46 0 29 1 0 1 1 0 8 0 phpool 112 657 0 19 19 0 19 19 0 8 0