panic: pool_cache_item_magic_check: mbufpl cpu free list modified: item addr 0xfffffd80665bfd00+24 0x3f71eec7181e91c8!=0xc08e13477e4571c8 Stopped at db_enter+0x18: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND *520716 3230 0 0x12 0 1 sshd 176352 88150 0 0x14000 0x200 0 softnet 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(ffffffff82664748) at pool_cache_get+0x323 pool_cache_item_magic_check sys/kern/subr_pool.c:1789 [inline] pool_cache_get(ffffffff82664748) 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(fffffd806d69ee00,580,5c,2) at m_copym+0x174 m_get sys/kern/uipc_mbuf.c:250 [inline] m_copym(fffffd806d69ee00,580,5c,2) at m_copym+0x174 sys/kern/uipc_mbuf.c:667 tcp_output(ffff800000a7c760) at tcp_output+0x151c sys/netinet/tcp_output.c:673 tcp_usrreq(fffffd806e98e908,9,fffffd806d69ee00,0,0,ffff800020ac1b38) at tcp_usrreq+0xa45 sosend(fffffd806e98e908,0,ffff800020aeb078,0,0,80) at sosend+0x645 sys/kern/uipc_socket.c:524 dofilewritev(ffff800020ac1b38,4,ffff800020aeb078,0,ffff800020aeb160) at dofilewritev+0x1b7 sys/kern/sys_generic.c:364 sys_write(ffff800020ac1b38,ffff800020aeb110,ffff800020aeb160) at sys_write+0x83 sys/kern/sys_generic.c:284 syscall(ffff800020aeb1e0) at syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:92 [inline] syscall(ffff800020aeb1e0) at syscall+0x4a4 sys/arch/amd64/amd64/trap.c:555 Xsyscall(6,4,f572de1616b,4,4,f59db7e6b00) at Xsyscall+0x128 end of kernel end trace frame: 0x7f7ffffc3720, 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 0xfffffd80665bfd00+24 0x3f71eec7181e91c8!=0xc08e13477e4571c8 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(ffffffff82664748) at pool_cache_get+0x323 pool_cache_item_magic_check sys/kern/subr_pool.c:1789 [inline] pool_cache_get(ffffffff82664748) 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(fffffd806d69ee00,580,5c,2) at m_copym+0x174 m_get sys/kern/uipc_mbuf.c:250 [inline] m_copym(fffffd806d69ee00,580,5c,2) at m_copym+0x174 sys/kern/uipc_mbuf.c:667 tcp_output(ffff800000a7c760) at tcp_output+0x151c sys/netinet/tcp_output.c:673 tcp_usrreq(fffffd806e98e908,9,fffffd806d69ee00,0,0,ffff800020ac1b38) at tcp_usrreq+0xa45 sosend(fffffd806e98e908,0,ffff800020aeb078,0,0,80) at sosend+0x645 sys/kern/uipc_socket.c:524 dofilewritev(ffff800020ac1b38,4,ffff800020aeb078,0,ffff800020aeb160) at dofilewritev+0x1b7 sys/kern/sys_generic.c:364 sys_write(ffff800020ac1b38,ffff800020aeb110,ffff800020aeb160) at sys_write+0x83 sys/kern/sys_generic.c:284 syscall(ffff800020aeb1e0) at syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:92 [inline] syscall(ffff800020aeb1e0) at syscall+0x4a4 sys/arch/amd64/amd64/trap.c:555 Xsyscall(6,4,f572de1616b,4,4,f59db7e6b00) at Xsyscall+0x128 end of kernel end trace frame: 0x7f7ffffc3720, count: -12 ddb{1}> show registers rdi 0 rsi 0x1 rbp 0xffff800020aeaa20 rbx 0xffff800020aeaad0 rdx 0xffff800020ac1b38 rcx 0 rax 0 r8 0xffffffff810c469f kprintf+0x16f r9 0x1 r10 0x25 r11 0x94856684fc78c1e4 r12 0x3000000008 r13 0xffff800020aeaa30 r14 0x100 r15 0x1 rip 0xffffffff8216a6f8 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff800020aeaa10 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{1}> show proc PROC (sshd) pid=520716 stat=onproc flags process=12 proc=0 pri=50, usrpri=50, nice=20 forw=0xffffffffffffffff, list=0xffff800020ac1648,0xffff800020ac1168 process=0xffff800020a8b890 user=0xffff800020ae6000, vmspace=0xfffffd806e7ec458 estcpu=0, cpticks=1, pctcpu=0.0 user=0, sys=1, intr=0 ddb{1}> ps PID TID PPID UID S FLAGS WAIT COMMAND 38868 166558 90571 0 3 0x80 nanosleep syz-executor.0 38868 225736 90571 0 3 0x4000080 netio syz-executor.0 38868 13148 90571 0 3 0x4000080 fsleep syz-executor.0 71001 299160 56425 0 3 0x2 biowait syz-executor.1 90571 350426 56425 0 3 0x82 nanosleep syz-executor.0 97183 7161 1 0 3 0x100083 ttyin getty 57575 317623 0 0 3 0x14200 acct acct 37597 173167 0 0 3 0x14200 bored sosplice 56425 154473 44859 0 3 0x82 thrsleep syz-fuzzer 56425 462263 44859 0 3 0x4000082 nanosleep syz-fuzzer 56425 443114 44859 0 3 0x4000082 thrsleep syz-fuzzer 56425 309205 44859 0 3 0x4000082 kqread syz-fuzzer 56425 180163 44859 0 3 0x4000082 thrsleep syz-fuzzer 56425 210241 44859 0 3 0x4000082 thrsleep syz-fuzzer 56425 175458 44859 0 3 0x4000082 thrsleep syz-fuzzer 56425 392957 44859 0 3 0x4000082 thrsleep syz-fuzzer 56425 100157 44859 0 3 0x4000082 thrsleep syz-fuzzer 56425 203649 44859 0 3 0x4000082 thrsleep syz-fuzzer 44859 204441 3230 0 3 0x10008a pause ksh * 3230 520716 1107 0 7 0x12 sshd 1107 359799 1 0 3 0x80 select sshd 70611 61616 57820 74 3 0x100092 bpf pflogd 57820 203232 1 0 3 0x80 netio pflogd 55837 96927 17813 73 3 0x100090 kqread syslogd 17813 25002 1 0 3 0x100082 netio syslogd 38874 215554 1 77 3 0x100090 poll dhclient 56293 489337 1 0 3 0x80 poll dhclient 23620 424176 0 0 3 0x14200 pgzero zerothread 65665 494902 0 0 3 0x14200 aiodoned aiodoned 58790 254568 0 0 3 0x14200 syncer update 6696 459672 0 0 3 0x14200 cleaner cleaner 71992 121327 0 0 3 0x14200 reaper reaper 29455 1730 0 0 3 0x14200 pgdaemon pagedaemon 61022 55195 0 0 3 0x14200 bored crynlk 41801 221819 0 0 3 0x14200 bored crypto 54292 127784 0 0 3 0x40014200 acpi0 acpi0 45780 20768 0 0 3 0x40014200 idle1 88150 176352 0 0 7 0x14200 softnet 63921 47192 0 0 3 0x14200 bored systqmp 33217 518037 0 0 3 0x14200 bored systq 63504 209723 0 0 3 0x40014200 bored softclock 51540 291669 0 0 3 0x40014200 idle0 40642 141978 0 0 3 0x14200 bored smr 1 366490 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb{1}> show all locks Process 71001 (syz-executor.1) thread 0xffff800020ab13d8 (299160) exclusive rrwlock inode r = 0 (0xfffffd806e79f0a8) #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 ufs_ihashins+0x45 sys/ufs/ufs/ufs_ihash.c:140 #4 ffs_vget+0x13e sys/ufs/ffs/ffs_vfsops.c:1352 #5 ffs_inode_alloc+0x1cf sys/ufs/ffs/ffs_alloc.c:392 #6 ufs_mkdir+0xf4 sys/ufs/ufs/ufs_vnops.c:1164 #7 VOP_MKDIR+0xc6 sys/kern/vfs_vops.c:450 #8 domkdirat+0x121 sys/kern/vfs_syscalls.c:2983 #9 syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:92 [inline] #9 syscall+0x4a4 sys/arch/amd64/amd64/trap.c:555 #10 Xsyscall+0x128 exclusive rrwlock inode r = 0 (0xfffffd806e79f2c8) #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:562 #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:2968 #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 Process 3230 (sshd) thread 0xffff800020ac1b38 (520716) exclusive rwlock netlock r = 0 (0xffffffff824b1938) #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 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{1}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim Kern Lim devbuf 9605 6459K 7931K 78643K 14385 0 0 pcb 13 8K 8K 78643K 549 0 0 rtable 113 9K 9K 78643K 1588 0 0 ifaddr 93 18K 19K 78643K 437 0 0 counters 39 33K 33K 78643K 39 0 0 ioctlops 0 0K 4K 78643K 1617 0 0 iov 0 0K 28K 78643K 462 0 0 mount 1 1K 1K 78643K 1 0 0 vnodes 1220 77K 77K 78643K 2901 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 50 0 0 VM map 12 6K 6K 78643K 25 0 0 sem 12 0K 1K 78643K 435 0 0 dirhash 12 2K 2K 78643K 12 0 0 ACPI 1808 196K 290K 78643K 12765 0 0 file desc 5 13K 25K 78643K 2441 0 0 sigio 0 0K 0K 78643K 39 0 0 proc 62 63K 95K 78643K 1326 0 0 subproc 32 2K 2K 78643K 327 0 0 NFS srvsock 1 0K 0K 78643K 1 0 0 NFS daemon 1 16K 16K 78643K 1 0 0 ip_moptions 0 0K 0K 78643K 203 0 0 in_multi 31 2K 2K 78643K 343 0 0 ether_multi 1 0K 0K 78643K 19 0 0 mrt 0 0K 0K 78643K 15 0 0 ISOFS mount 1 32K 32K 78643K 1 0 0 MSDOSFS mount 1 16K 16K 78643K 1 0 0 ttys 96 424K 424K 78643K 96 0 0 exec 0 0K 1K 78643K 696 0 0 pfkey data 0 0K 0K 78643K 4 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 133 136K 137K 78643K 9758 0 0 UVM aobj 130 8K 8K 78643K 143 0 0 memdesc 1 4K 4K 78643K 1 0 0 crypto data 1 1K 1K 78643K 1 0 0 ip6_options 0 0K 0K 78643K 510 0 0 NDP 22 0K 0K 78643K 144 0 0 temp 244 3565K 4204K 78643K 61510 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 49 0 43 1 0 1 1 0 8 0 plcache 128 20 0 0 1 0 1 1 0 8 0 rtpcb 80 200 0 198 1 0 1 1 0 8 0 rtentry 112 301 0 259 2 0 2 2 0 8 0 unpcb 120 1155 0 1142 1 0 1 1 0 8 0 syncache 264 14 0 14 7 7 0 1 0 8 0 sackhl 24 1 0 1 1 1 0 1 0 8 0 tcpqe 32 6456 0 6456 5 5 0 2 0 8 0 tcpcb 544 1731 0 1724 5 4 1 4 0 8 0 inpcb 280 5985 0 5972 12 9 3 4 0 8 2 rttmr 72 6 0 5 5 4 1 1 0 8 0 ip6q 72 1 0 1 1 1 0 1 0 8 0 ip6af 40 3 0 3 1 1 0 1 0 8 0 nd6 48 49 0 46 2 1 1 1 0 8 0 pkpcb 40 11 0 11 6 6 0 1 0 8 0 ppxss 1128 41 0 41 7 7 0 1 0 8 0 pffrag 232 44 0 44 10 9 1 1 0 482 1 pffrnode 88 44 0 44 10 9 1 1 0 8 1 pffrent 40 913 0 913 10 9 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 24 181 0 122 1 0 1 1 0 8 0 pfstkey 112 181 0 122 3 0 3 3 0 8 0 pfstate 328 181 0 122 7 0 7 7 0 8 0 pfrule 1360 21 0 16 2 1 1 2 0 8 0 art_heap8 4096 3 0 2 3 1 2 3 0 8 1 art_heap4 256 1325 0 1095 27 12 15 16 0 8 0 art_table 32 1328 0 1097 3 1 2 3 0 8 0 art_node 16 299 0 260 1 0 1 1 0 8 0 sysvmsgpl 40 11 0 6 1 0 1 1 0 8 0 semupl 112 3 0 3 1 1 0 1 0 8 0 semapl 112 431 0 421 1 0 1 1 0 8 0 shmpl 112 141 0 13 4 0 4 4 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino1pl 128 4979 0 3570 46 0 46 46 0 8 0 ffsino 272 4979 0 3570 96 1 95 95 0 8 0 nchpl 144 8557 0 8099 61 40 21 61 0 8 0 uvmvnodes 72 5926 0 0 108 0 108 108 0 8 0 vnodes 208 5926 0 0 312 0 312 312 0 8 0 namei 1024 30957 0 30956 4 3 1 1 0 8 0 percpumem 16 30 0 0 1 0 1 1 0 8 0 vcpupl 1984 11 0 1 2 0 2 2 0 8 0 vmpool 552 23 0 13 1 0 1 1 0 8 0 scsiplug 64 2 0 2 1 1 0 1 0 8 0 scxspl 192 29308 0 29307 27 26 1 7 0 8 0 plimitpl 152 193 0 185 1 0 1 1 0 8 0 sigapl 432 2591 0 2576 5 3 2 3 0 8 0 futexpl 56 50947 0 50946 1 0 1 1 0 8 0 knotepl 112 644 0 625 2 1 1 2 0 8 0 kqueuepl 104 651 0 648 1 0 1 1 0 8 0 pipepl 112 1610 0 1591 6 5 1 2 0 8 0 fdescpl 488 2592 0 2576 3 0 3 3 0 8 0 filepl 152 22083 0 21976 17 11 6 7 0 8 1 lockfpl 104 849 0 847 1 0 1 1 0 8 0 lockfspl 48 262 0 260 1 0 1 1 0 8 0 sessionpl 112 36 0 25 1 0 1 1 0 8 0 pgrppl 48 78 0 67 1 0 1 1 0 8 0 ucredpl 96 2554 0 2545 1 0 1 1 0 8 0 zombiepl 144 2576 0 2576 4 3 1 1 0 8 1 processpl 896 2609 0 2576 4 0 4 4 0 8 0 procpl 632 8125 0 8081 7 2 5 5 0 8 1 srpgc 64 24 0 24 6 6 0 1 0 8 0 sosppl 128 29 0 29 7 6 1 1 0 8 1 sockpl 384 7397 0 7369 18 13 5 7 0 8 1 mcl64k 65536 266 0 0 34 8 26 34 0 8 1 mcl16k 16384 24 0 0 3 1 2 3 0 8 0 mcl12k 12288 17 0 0 2 0 2 2 0 8 0 mcl9k 9216 12 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 8 0 0 1 0 1 1 0 8 0 mcl2k 2048 249 0 0 28 1 27 28 0 8 0 mtagpl 80 70 0 0 2 0 2 2 0 8 0 mbufpl 256 501 0 0 25 1 24 24 0 8 0 bufpl 256 14581 0 7533 441 0 441 441 0 8 0 anonpl 16 305814 0 290172 137 59 78 87 0 124 6 amapchunkpl 152 19120 0 19002 42 36 6 13 0 158 0 amappl16 192 13222 0 12244 131 72 59 62 0 8 8 amappl15 184 361 0 361 2 2 0 1 0 8 0 amappl14 176 716 0 709 2 1 1 1 0 8 0 amappl13 168 290 0 290 3 3 0 1 0 8 0 amappl12 160 306 0 303 2 1 1 1 0 8 0 amappl11 152 166 0 151 1 0 1 1 0 8 0 amappl10 144 38 0 35 1 0 1 1 0 8 0 amappl9 136 1409 0 1402 1 0 1 1 0 8 0 amappl8 128 959 0 922 2 0 2 2 0 8 0 amappl7 120 119 0 110 1 0 1 1 0 8 0 amappl6 112 159 0 147 1 0 1 1 0 8 0 amappl5 104 600 0 584 1 0 1 1 0 8 0 amappl4 96 2590 0 2558 1 0 1 1 0 8 0 amappl3 88 896 0 888 1 0 1 1 0 8 0 amappl2 80 19394 0 19320 3 1 2 3 0 8 0 amappl1 72 69313 0 68869 26 16 10 20 0 8 0 amappl 80 8679 0 8631 3 1 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 17 0 17 1 1 0 1 0 8 0 aobjpl 64 142 0 13 4 1 3 3 0 8 0 uaddrrnd 24 2615 0 2576 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 2615 0 2576 1 0 1 1 0 8 0 vmmpekpl 168 25264 0 25225 2 0 2 2 0 8 0 vmmpepl 168 340277 0 338138 240 109 131 133 0 357 28 vmsppl 368 2591 0 2576 2 0 2 2 0 8 0 pdppl 4096 5237 0 5188 10 3 7 7 0 8 0 pvpl 32 848467 0 829608 289 95 194 206 0 265 26 pmappl 232 2614 0 2589 3 1 2 2 0 8 0 extentpl 40 41 0 26 1 0 1 1 0 8 0 phpool 112 691 0 38 19 0 19 19 0 8 0