panic: pool_cache_item_magic_check: mbufpl cpu free list modified: item addr 0xfffffd807b0d4900+16 0x0!=0x2f5cdb7efd40db0e Stopped at db_enter+0x18: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND *442350 98639 0 0 0x4000000 1 syz-executor.0 173391 99433 0 0x2 0x4000480 0 syz-fuzzer 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(ffffffff826411d0) at pool_cache_get+0x323 pool_cache_item_magic_check sys/kern/subr_pool.c:1789 [inline] pool_cache_get(ffffffff826411d0) 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(fffffd8063d30700,a8d4,5a0,2) at m_copym+0x174 m_get sys/kern/uipc_mbuf.c:250 [inline] m_copym(fffffd8063d30700,a8d4,5a0,2) at m_copym+0x174 sys/kern/uipc_mbuf.c:667 ip_fragment(fffffd8063d30700,ffff8000001732a8,5b4) at ip_fragment+0x324 ip_output(fffffd8063d30700,0,fffffd806f6cc070,20,0,fffffd806f6cc000) at ip_output+0xfc1 sys/netinet/ip_output.c:501 rip_output(fffffd8063d30700,fffffd80633d17a0,ffff800023bddb98,ffff800021b82000) at rip_output+0x252 sys/netinet/raw_ip.c:289 rip_usrreq(fffffd80633d17a0,9,fffffd8063d30700,0,0,ffff800020abf3e8) at rip_usrreq+0x46a sys/netinet/raw_ip.c:538 sosend(fffffd80633d17a0,0,ffff800023bddd00,0,0,0) at sosend+0x645 sys/kern/uipc_socket.c:524 sendit(ffff800020abf3e8,7,ffff800023bddde0,0,ffff800023bddec0) at sendit+0x52b sys/kern/uipc_syscalls.c:662 sys_sendto(ffff800020abf3e8,ffff800023bdde78,ffff800023bddec0) at sys_sendto+0x80 sys/kern/uipc_syscalls.c:527 syscall(ffff800023bddf40) at syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:92 [inline] syscall(ffff800023bddf40) at syscall+0x4a4 sys/arch/amd64/amd64/trap.c:555 Xsyscall(0,0,ffffffffffffffd7,0,6,4da8f0a1010) at Xsyscall+0x128 end of kernel end trace frame: 0x4dcdda5eb50, count: 1 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 0xfffffd807b0d4900+16 0x0!=0x2f5cdb7efd40db0e 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(ffffffff826411d0) at pool_cache_get+0x323 pool_cache_item_magic_check sys/kern/subr_pool.c:1789 [inline] pool_cache_get(ffffffff826411d0) 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(fffffd8063d30700,a8d4,5a0,2) at m_copym+0x174 m_get sys/kern/uipc_mbuf.c:250 [inline] m_copym(fffffd8063d30700,a8d4,5a0,2) at m_copym+0x174 sys/kern/uipc_mbuf.c:667 ip_fragment(fffffd8063d30700,ffff8000001732a8,5b4) at ip_fragment+0x324 ip_output(fffffd8063d30700,0,fffffd806f6cc070,20,0,fffffd806f6cc000) at ip_output+0xfc1 sys/netinet/ip_output.c:501 rip_output(fffffd8063d30700,fffffd80633d17a0,ffff800023bddb98,ffff800021b82000) at rip_output+0x252 sys/netinet/raw_ip.c:289 rip_usrreq(fffffd80633d17a0,9,fffffd8063d30700,0,0,ffff800020abf3e8) at rip_usrreq+0x46a sys/netinet/raw_ip.c:538 sosend(fffffd80633d17a0,0,ffff800023bddd00,0,0,0) at sosend+0x645 sys/kern/uipc_socket.c:524 sendit(ffff800020abf3e8,7,ffff800023bddde0,0,ffff800023bddec0) at sendit+0x52b sys/kern/uipc_syscalls.c:662 sys_sendto(ffff800020abf3e8,ffff800023bdde78,ffff800023bddec0) at sys_sendto+0x80 sys/kern/uipc_syscalls.c:527 syscall(ffff800023bddf40) at syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:92 [inline] syscall(ffff800023bddf40) at syscall+0x4a4 sys/arch/amd64/amd64/trap.c:555 Xsyscall(0,0,ffffffffffffffd7,0,6,4da8f0a1010) at Xsyscall+0x128 end of kernel end trace frame: 0x4dcdda5eb50, count: -14 ddb{1}> show registers rdi 0xffffffff81c952f7 db_enter+0x17 rsi 0x6bb8 __ALIGN_SIZE+0x5bb8 rbp 0xffff800023bdd6c0 rbx 0xffff800023bdd770 rdx 0x6bb9 __ALIGN_SIZE+0x5bb9 rcx 0xffff800021b82000 rax 0xffff800021b82000 r8 0xffffffff8199ba8f kprintf+0x16f r9 0x1 r10 0x25 r11 0x13cae093011f2a5f r12 0x3000000008 r13 0xffff800023bdd6d0 r14 0x100 r15 0x1 rip 0xffffffff81c952f8 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff800023bdd6b0 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{1}> show proc PROC (syz-executor.0) pid=442350 stat=onproc flags process=0 proc=4000000 pri=86, usrpri=86, nice=20 forw=0xffffffffffffffff, list=0xffff800020abec80,0xffffffff8263f188 process=0xffff800020add500 user=0xffff800023bd8000, vmspace=0xfffffd807f00b450 estcpu=36, cpticks=1, pctcpu=0.0 user=0, sys=1, intr=0 ddb{1}> ps PID TID PPID UID S FLAGS WAIT COMMAND 98639 19380 68618 0 2 0 syz-executor.0 *98639 442350 68618 0 7 0x4000000 syz-executor.0 68618 84179 99433 0 2 0x482 syz-executor.0 29954 321882 99433 0 2 0x2 syz-executor.1 52061 56055 0 0 3 0x14200 acct acct 10129 286585 1 0 3 0x100083 ttyin getty 23112 82099 0 0 3 0x14200 bored sosplice 99433 103183 7735 0 3 0x82 thrsleep syz-fuzzer 99433 308349 7735 0 3 0x4000082 nanosleep syz-fuzzer 99433 139306 7735 0 3 0x4000082 thrsleep syz-fuzzer 99433 173391 7735 0 7 0x4000482 syz-fuzzer 99433 171009 7735 0 3 0x4000082 thrsleep syz-fuzzer 99433 18402 7735 0 3 0x4000082 thrsleep syz-fuzzer 99433 397708 7735 0 3 0x4000082 kqread syz-fuzzer 99433 282357 7735 0 3 0x4000082 thrsleep syz-fuzzer 99433 383030 7735 0 3 0x4000082 thrsleep syz-fuzzer 99433 402591 7735 0 3 0x4000082 thrsleep syz-fuzzer 7735 450945 64343 0 3 0x10008a pause ksh 64343 98323 49815 0 3 0x92 select sshd 49815 342955 1 0 3 0x80 select sshd 15686 49368 71343 74 3 0x100092 bpf pflogd 71343 162311 1 0 3 0x80 netio pflogd 62369 170021 34225 73 3 0x100090 kqread syslogd 34225 488098 1 0 3 0x100082 netio syslogd 82656 13930 1 77 3 0x100090 poll dhclient 49342 336613 1 0 3 0x80 poll dhclient 1218 419926 0 0 2 0x14200 zerothread 98002 238416 0 0 3 0x14200 aiodoned aiodoned 80892 406153 0 0 3 0x14200 syncer update 12895 9189 0 0 3 0x14200 cleaner cleaner 71101 162819 0 0 3 0x14200 reaper reaper 44340 42146 0 0 3 0x14200 pgdaemon pagedaemon 31607 225994 0 0 3 0x14200 bored crynlk 13614 101359 0 0 3 0x14200 bored crypto 55331 141023 0 0 3 0x40014200 acpi0 acpi0 46382 150683 0 0 3 0x40014200 idle1 30829 180549 0 0 3 0x14200 bored softnet 92865 522348 0 0 3 0x14200 bored systqmp 16632 483131 0 0 3 0x14200 bored systq 88499 50948 0 0 3 0x40014200 bored softclock 46298 305370 0 0 3 0x40014200 idle0 93720 366484 0 0 3 0x14200 bored smr 1 219302 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb{1}> show all locks Process 98639 (syz-executor.0) thread 0xffff800020abf3e8 (442350) exclusive rwlock netlock r = 0 (0xffffffff824d0138) #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 29954 (syz-executor.1) thread 0xffff800020abfb50 (321882) exclusive rrwlock inode r = 0 (0xfffffd80714f13d8) #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:574 #5 vget+0x1c3 sys/kern/vfs_subr.c:672 #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+0x14b4 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:1785 #13 syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:92 [inline] #13 syscall+0x4a4 sys/arch/amd64/amd64/trap.c:555 #14 Xsyscall+0x128 exclusive rrwlock inode r = 0 (0xfffffd8072cdaa28) #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:574 #5 vfs_lookup+0xe6 sys/kern/vfs_lookup.c:419 #6 namei+0x63c sys/kern/vfs_lookup.c:249 #7 dounlinkat+0x99 sys/kern/vfs_syscalls.c:1785 #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 9633 6491K 9224K 78643K 56049 0 0 pcb 13 12K 14K 78643K 1696 0 0 rtable 123 14K 16K 78643K 5554 0 0 ifaddr 105 27K 29K 78643K 1616 0 0 counters 39 33K 33K 78643K 39 0 0 ioctlops 0 0K 4K 78643K 1985 0 0 iov 0 0K 32K 78643K 1543 0 0 mount 1 1K 1K 78643K 1 0 0 vnodes 1235 78K 78K 78643K 14163 0 0 UFS quota 1 32K 32K 78643K 1 0 0 UFS mount 5 36K 36K 78643K 5 0 0 shm 2 1K 9K 78643K 132 0 0 VM map 81 40K 41K 78643K 114 0 0 sem 12 0K 1K 78643K 3525 0 0 dirhash 12 2K 2K 78643K 12 0 0 ACPI 1808 196K 290K 78643K 12765 0 0 file desc 5 13K 25K 78643K 8264 0 0 sigio 0 0K 0K 78643K 121 0 0 proc 62 63K 95K 78643K 3779 0 0 subproc 32 2K 2K 78643K 1054 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 898 0 0 in_multi 30 1K 2K 78643K 1108 0 0 ether_multi 1 0K 0K 78643K 101 0 0 mrt 1 0K 0K 78643K 52 0 0 ISOFS mount 1 32K 32K 78643K 1 0 0 MSDOSFS mount 1 16K 16K 78643K 1 0 0 ttys 120 530K 530K 78643K 120 0 0 exec 0 0K 1K 78643K 1801 0 0 pfkey data 0 0K 4K 78643K 6 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 246 683K 685K 78643K 30126 0 0 UVM aobj 130 4K 4K 78643K 140 0 0 memdesc 1 4K 4K 78643K 1 0 0 crypto data 1 1K 1K 78643K 1 0 0 ip6_options 0 0K 2K 78643K 1794 0 0 NDP 24 0K 1K 78643K 508 0 0 temp 258 3565K 4209K 78643K 415549 0 0 kqueue 0 0K 0K 78643K 50 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 64 204 0 197 1 0 1 1 0 8 0 plcache 128 20 0 0 1 0 1 1 0 8 0 rtpcb 80 796 0 794 1 0 1 1 0 8 0 rtentry 112 967 0 924 2 0 2 2 0 8 0 unpcb 120 4422 0 4407 8 7 1 2 0 8 0 syncache 264 44 0 44 21 21 0 1 0 8 0 sackhl 24 3 0 3 2 2 0 1 0 8 0 tcpqe 32 70 0 70 11 11 0 1 0 8 0 tcpcb 544 3786 0 3782 51 50 1 13 0 8 0 inpcb 280 11386 0 11377 54 52 2 13 0 8 1 rttmr 72 18 0 17 3 2 1 1 0 8 0 ip6q 72 3 0 3 3 3 0 1 0 8 0 ip6af 40 5 0 5 2 2 0 1 0 8 0 nd6 48 144 0 142 2 1 1 1 0 8 0 pkpcb 40 53 0 53 16 16 0 1 0 8 0 swfcl 56 2 0 0 1 0 1 1 0 8 0 ppxss 1128 236 0 236 22 21 1 1 0 8 1 pffrag 232 217 0 214 16 15 1 1 0 482 0 pffrnode 88 200 0 198 16 15 1 1 0 8 0 pffrent 40 7314 0 7311 17 16 1 2 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 24 739 0 677 1 0 1 1 0 8 0 pfstkey 112 739 0 677 4 1 3 3 0 8 1 pfstate 328 739 0 677 12 6 6 9 0 8 0 pfrule 1360 21 0 16 2 1 1 2 0 8 0 art_heap8 4096 3 0 2 3 2 1 2 0 8 0 art_heap4 256 3929 0 3684 40 22 18 20 0 8 2 art_table 32 3932 0 3686 7 4 3 3 0 8 0 art_node 16 963 0 923 1 0 1 1 0 8 0 sysvmsgpl 40 23 0 17 2 1 1 1 0 8 0 semupl 112 1 0 1 1 1 0 1 0 8 0 semapl 112 3523 0 3513 1 0 1 1 0 8 0 shmpl 112 138 0 10 4 0 4 4 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino1pl 128 14795 0 13351 47 0 47 47 0 8 0 ffsino 272 14795 0 13351 97 0 97 97 0 8 0 nchpl 144 27828 0 27354 61 40 21 61 0 8 0 uvmvnodes 72 6450 0 0 118 0 118 118 0 8 0 vnodes 208 6450 0 0 340 0 340 340 0 8 0 namei 1024 106755 0 106755 3 2 1 1 0 8 1 percpumem 16 30 0 0 1 0 1 1 0 8 0 vcpupl 1984 79 0 0 10 0 10 10 0 8 0 vmpool 552 112 0 33 8 2 6 6 0 8 0 scsiplug 64 11 0 11 9 9 0 1 0 8 0 scxspl 192 86379 0 86379 63 60 3 7 0 8 3 plimitpl 152 647 0 639 1 0 1 1 0 8 0 sigapl 432 8288 0 8273 6 4 2 3 0 8 0 futexpl 56 206177 0 206177 2 1 1 1 0 8 1 knotepl 112 2811 0 2792 13 12 1 3 0 8 0 kqueuepl 104 2892 0 2890 16 15 1 4 0 8 0 pipepl 112 4822 0 4803 15 14 1 2 0 8 0 fdescpl 488 8289 0 8273 3 0 3 3 0 8 0 filepl 152 76399 0 76296 77 71 6 14 0 8 2 lockfpl 104 2832 0 2831 1 0 1 1 0 8 0 lockfspl 48 1003 0 1002 1 0 1 1 0 8 0 sessionpl 112 82 0 71 1 0 1 1 0 8 0 pgrppl 48 162 0 151 1 0 1 1 0 8 0 ucredpl 96 12491 0 12481 1 0 1 1 0 8 0 zombiepl 144 8282 0 8282 3 2 1 1 0 8 1 processpl 896 8315 0 8282 6 2 4 5 0 8 0 procpl 632 26292 0 26249 6 1 5 5 0 8 0 srpgc 64 88 0 88 25 25 0 1 0 8 0 sosppl 128 138 0 138 25 24 1 1 0 8 1 sockpl 384 16770 0 16744 90 86 4 22 0 8 0 mcl64k 65536 817 0 0 95 41 54 65 0 8 1 mcl16k 16384 33 0 0 5 2 3 3 0 8 0 mcl12k 12288 40 0 0 2 0 2 2 0 8 0 mcl9k 9216 34 0 0 2 0 2 2 0 8 0 mcl8k 8192 17 0 0 3 0 3 3 0 8 0 mcl4k 4096 25 0 0 4 1 3 3 0 8 0 mcl2k2 2112 15 0 0 1 0 1 1 0 8 0 mcl2k 2048 231 0 0 23 9 14 23 0 8 0 mtagpl 80 766 0 0 7 0 7 7 0 8 0 mbufpl 256 1608 0 0 77 0 77 77 0 8 0 bufpl 256 32174 0 25126 441 0 441 441 0 8 0 anonpl 16 1008971 0 987723 296 194 102 104 0 124 13 amapchunkpl 152 62574 0 62382 82 67 15 22 0 158 5 amappl16 192 44354 0 43142 283 216 67 73 0 8 6 amappl15 184 1172 0 1169 1 0 1 1 0 8 0 amappl14 176 1636 0 1635 1 0 1 1 0 8 0 amappl13 168 1041 0 1040 12 11 1 1 0 8 0 amappl12 160 1537 0 1534 2 1 1 1 0 8 0 amappl11 152 671 0 656 1 0 1 1 0 8 0 amappl10 144 1323 0 1317 1 0 1 1 0 8 0 amappl9 136 2222 0 2214 1 0 1 1 0 8 0 amappl8 128 1805 0 1748 2 0 2 2 0 8 0 amappl7 120 1570 0 1561 1 0 1 1 0 8 0 amappl6 112 629 0 617 1 0 1 1 0 8 0 amappl5 104 2139 0 2124 1 0 1 1 0 8 0 amappl4 96 7703 0 7666 1 0 1 1 0 8 0 amappl3 88 3321 0 3308 1 0 1 1 0 8 0 amappl2 80 62310 0 62229 3 1 2 3 0 8 0 amappl1 72 197269 0 196836 25 15 10 20 0 8 0 amappl 80 27651 0 27561 3 0 3 3 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 64 139 0 10 3 0 3 3 0 8 0 uaddrrnd 24 8401 0 8273 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 8401 0 8273 1 0 1 1 0 8 0 vmmpekpl 168 64461 0 64408 3 0 3 3 0 8 0 vmmpepl 168 1066881 0 1064311 376 220 156 158 0 357 35 vmsppl 368 8288 0 8273 2 0 2 2 0 8 0 pdppl 4096 16809 0 16691 24 8 16 16 0 8 1 pvpl 32 2576776 0 2554694 512 295 217 221 0 265 30 pmappl 232 8400 0 8306 7 1 6 6 0 8 0 extentpl 40 41 0 26 1 0 1 1 0 8 0 phpool 112 875 0 140 22 0 22 22 0 8 0