panic: pool_cache_item_magic_check: mbufpl cpu free list modified: item addr 0xfffffd806258b500+16 0xcb00000000000000!=0xcbe8bbf3b2ece2c8 Stopped at db_enter+0x18: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND *306481 19766 0 0 0x4000000 1 syz-executor.1 322713 69965 0 0x14000 0x200 0 smr 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(ffffffff82662ab8) at pool_cache_get+0x323 pool_cache_item_magic_check sys/kern/subr_pool.c:1789 [inline] pool_cache_get(ffffffff82662ab8) 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(fffffd806800d900,6554,5a0,2) at m_copym+0x174 m_get sys/kern/uipc_mbuf.c:250 [inline] m_copym(fffffd806800d900,6554,5a0,2) at m_copym+0x174 sys/kern/uipc_mbuf.c:667 ip_fragment(fffffd806800d900,ffff8000001732a8,5b4) at ip_fragment+0x324 ip_output(fffffd806800d900,0,fffffd806f6ca188,0,0,fffffd806f6ca118) at ip_output+0xfc1 sys/netinet/ip_output.c:501 udp_output(fffffd806f6ca118,fffffd806800d900,0,0) at udp_output+0x5af sys/netinet/udp_usrreq.c:1004 sosend(fffffd807a405310,0,ffff8000239bb3a0,0,0,0) at sosend+0x645 sys/kern/uipc_socket.c:524 sendit(ffff800020a5e280,6,ffff8000239bb480,0,ffff8000239bb560) at sendit+0x52b sys/kern/uipc_syscalls.c:662 sys_sendto(ffff800020a5e280,ffff8000239bb518,ffff8000239bb560) at sys_sendto+0x80 sys/kern/uipc_syscalls.c:527 syscall(ffff8000239bb5e0) at syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:92 [inline] syscall(ffff8000239bb5e0) at syscall+0x4a4 sys/arch/amd64/amd64/trap.c:555 Xsyscall(6,0,ffffffffffffffd7,0,6,34f7463010) at Xsyscall+0x128 end of kernel end trace frame: 0x3767027500, 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 0xfffffd806258b500+16 0xcb00000000000000!=0xcbe8bbf3b2ece2c8 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(ffffffff82662ab8) at pool_cache_get+0x323 pool_cache_item_magic_check sys/kern/subr_pool.c:1789 [inline] pool_cache_get(ffffffff82662ab8) 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(fffffd806800d900,6554,5a0,2) at m_copym+0x174 m_get sys/kern/uipc_mbuf.c:250 [inline] m_copym(fffffd806800d900,6554,5a0,2) at m_copym+0x174 sys/kern/uipc_mbuf.c:667 ip_fragment(fffffd806800d900,ffff8000001732a8,5b4) at ip_fragment+0x324 ip_output(fffffd806800d900,0,fffffd806f6ca188,0,0,fffffd806f6ca118) at ip_output+0xfc1 sys/netinet/ip_output.c:501 udp_output(fffffd806f6ca118,fffffd806800d900,0,0) at udp_output+0x5af sys/netinet/udp_usrreq.c:1004 sosend(fffffd807a405310,0,ffff8000239bb3a0,0,0,0) at sosend+0x645 sys/kern/uipc_socket.c:524 sendit(ffff800020a5e280,6,ffff8000239bb480,0,ffff8000239bb560) at sendit+0x52b sys/kern/uipc_syscalls.c:662 sys_sendto(ffff800020a5e280,ffff8000239bb518,ffff8000239bb560) at sys_sendto+0x80 sys/kern/uipc_syscalls.c:527 syscall(ffff8000239bb5e0) at syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:92 [inline] syscall(ffff8000239bb5e0) at syscall+0x4a4 sys/arch/amd64/amd64/trap.c:555 Xsyscall(6,0,ffffffffffffffd7,0,6,34f7463010) at Xsyscall+0x128 end of kernel end trace frame: 0x3767027500, count: -13 ddb{1}> show registers rdi 0xffffffff812a9ce7 db_enter+0x17 rsi 0x81b9 __ALIGN_SIZE+0x71b9 rbp 0xffff8000239badb0 rbx 0xffff8000239bae60 rdx 0x81ba __ALIGN_SIZE+0x71ba rcx 0xffff800020b76000 rax 0xffff800020b76000 r8 0xffffffff819a376f kprintf+0x16f r9 0x1 r10 0x25 r11 0x7c7a32233b518985 r12 0x3000000008 r13 0xffff8000239badc0 r14 0x100 r15 0x1 rip 0xffffffff812a9ce8 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff8000239bada0 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{1}> show proc PROC (syz-executor.1) pid=306481 stat=onproc flags process=0 proc=4000000 pri=77, usrpri=77, nice=20 forw=0xffffffffffffffff, list=0xffff800020a5e9e8,0xffff800020abec80 process=0xffff800020adce00 user=0xffff8000239b6000, vmspace=0xfffffd807f00a5c0 estcpu=36, cpticks=2, pctcpu=0.0 user=0, sys=1, intr=0 ddb{1}> ps PID TID PPID UID S FLAGS WAIT COMMAND 19766 489116 96404 0 2 0 syz-executor.1 *19766 306481 96404 0 7 0x4000000 syz-executor.1 57045 47683 6697 0 2 0 syz-executor.0 57045 190726 6697 0 3 0x4000080 ttyout syz-executor.0 57045 339452 6697 0 2 0x4000000 syz-executor.0 96404 334917 19826 0 2 0x482 syz-executor.1 6697 284547 19826 0 2 0x482 syz-executor.0 61881 160037 0 0 3 0x14200 bored sosplice 19826 270526 25792 0 3 0x82 thrsleep syz-fuzzer 19826 516575 25792 0 3 0x4000082 thrsleep syz-fuzzer 19826 197363 25792 0 3 0x4000082 thrsleep syz-fuzzer 19826 241243 25792 0 3 0x4000082 thrsleep syz-fuzzer 19826 352693 25792 0 3 0x4000082 thrsleep syz-fuzzer 19826 354682 25792 0 3 0x4000082 thrsleep syz-fuzzer 19826 151703 25792 0 3 0x4000082 thrsleep syz-fuzzer 19826 205058 25792 0 3 0x4000082 thrsleep syz-fuzzer 19826 421943 25792 0 3 0x4000082 kqread syz-fuzzer 19826 214529 25792 0 3 0x4000082 thrsleep syz-fuzzer 25792 473384 25391 0 3 0x10008a pause ksh 25391 146244 30566 0 3 0x92 select sshd 6923 311816 1 0 3 0x100083 ttyin getty 30566 36101 1 0 3 0x80 select sshd 71676 325097 66032 74 3 0x100092 bpf pflogd 66032 94781 1 0 3 0x80 netio pflogd 44393 42529 4682 73 3 0x100090 kqread syslogd 4682 511135 1 0 3 0x100082 netio syslogd 85013 457134 1 77 3 0x100090 poll dhclient 24415 81948 1 0 3 0x80 poll dhclient 3297 309534 0 0 2 0x14200 zerothread 71581 314708 0 0 3 0x14200 aiodoned aiodoned 62645 128084 0 0 3 0x14200 syncer update 66671 190996 0 0 3 0x14200 cleaner cleaner 76243 14548 0 0 3 0x14200 reaper reaper 11137 418335 0 0 3 0x14200 pgdaemon pagedaemon 79842 278872 0 0 3 0x14200 bored crynlk 96908 141314 0 0 3 0x14200 bored crypto 99376 391280 0 0 3 0x40014200 acpi0 acpi0 49732 68241 0 0 3 0x40014200 idle1 75282 402664 0 0 3 0x14200 bored softnet 73506 310826 0 0 3 0x14200 bored systqmp 12807 114962 0 0 3 0x14200 bored systq 52686 93938 0 0 3 0x40014200 bored softclock 75920 144823 0 0 3 0x40014200 idle0 69965 322713 0 0 7 0x14200 smr 1 408960 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb{1}> show all locks Process 19766 (syz-executor.1) thread 0xffff800020a5e280 (306481) exclusive rwlock netlock r = 0 (0xffffffff82516718) #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 ddb{1}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim Kern Lim devbuf 9592 6514K 8320K 78643K 24727 0 0 pcb 13 10K 12K 78643K 567 0 0 rtable 112 13K 14K 78643K 2174 0 0 ifaddr 85 19K 21K 78643K 629 0 0 counters 39 33K 33K 78643K 39 0 0 ioctlops 0 0K 4K 78643K 1631 0 0 iov 0 0K 24K 78643K 496 0 0 mount 1 1K 1K 78643K 1 0 0 vnodes 1241 78K 79K 78643K 5323 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 34 0 0 VM map 27 13K 13K 78643K 32 0 0 sem 12 0K 0K 78643K 1045 0 0 dirhash 12 2K 2K 78643K 12 0 0 ACPI 1808 196K 290K 78643K 12765 0 0 file desc 6 17K 25K 78643K 2761 0 0 sigio 0 0K 0K 78643K 33 0 0 proc 62 63K 95K 78643K 1460 0 0 subproc 32 2K 2K 78643K 357 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 316 0 0 in_multi 30 2K 2K 78643K 375 0 0 ether_multi 1 0K 0K 78643K 31 0 0 mrt 0 0K 0K 78643K 13 0 0 ISOFS mount 1 32K 32K 78643K 1 0 0 MSDOSFS mount 1 16K 16K 78643K 1 0 0 ttys 78 344K 344K 78643K 78 0 0 exec 0 0K 1K 78643K 717 0 0 pfkey data 0 0K 0K 78643K 1 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 156 250K 252K 78643K 10775 0 0 UVM aobj 130 4K 4K 78643K 134 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 591 0 0 NDP 20 0K 1K 78643K 201 0 0 temp 228 3565K 4200K 78643K 103314 0 0 kqueue 0 0K 0K 78643K 27 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 84 0 79 1 0 1 1 0 8 0 plcache 128 20 0 0 1 0 1 1 0 8 0 rtpcb 80 247 0 245 1 0 1 1 0 8 0 rtentry 112 364 0 324 2 0 2 2 0 8 0 unpcb 120 4477 0 4463 2 1 1 2 0 8 0 syncache 264 15 0 15 9 9 0 1 0 8 0 sackhl 24 1 0 1 1 1 0 1 0 8 0 tcpqe 32 99 0 99 6 6 0 1 0 8 0 tcpcb 544 1059 0 1055 4 3 1 4 0 8 0 inpcb 280 5036 0 5028 20 18 2 13 0 8 1 rttmr 72 5 0 4 1 0 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 52 0 49 2 1 1 1 0 8 0 pkpcb 40 8 0 8 3 3 0 1 0 8 0 swfcl 56 2 0 0 1 0 1 1 0 8 0 ppxss 1128 88 0 88 11 10 1 1 0 8 1 pffrag 232 616 0 616 5 4 1 4 0 482 1 pffrnode 88 545 0 545 1 0 1 1 0 8 1 pffrent 40 23673 0 23673 2 1 1 2 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 24 199 0 134 1 0 1 1 0 8 0 pfstkey 112 199 0 134 3 0 3 3 0 8 0 pfstate 328 199 0 134 6 0 6 6 0 8 0 pfrule 1360 21 0 16 2 1 1 2 0 8 0 art_heap8 4096 2 0 1 2 1 1 2 0 8 0 art_heap4 256 1560 0 1335 27 11 16 23 0 8 0 art_table 32 1562 0 1336 4 1 3 3 0 8 0 art_node 16 362 0 325 1 0 1 1 0 8 0 sysvmsgpl 40 11 0 5 1 0 1 1 0 8 0 semapl 112 1041 0 1031 1 0 1 1 0 8 0 shmpl 112 132 0 4 4 0 4 4 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino1pl 128 5456 0 4047 46 0 46 46 0 8 0 ffsino 272 5456 0 4047 95 0 95 95 0 8 0 nchpl 144 9425 0 8943 61 40 21 61 0 8 0 uvmvnodes 72 6069 0 0 111 0 111 111 0 8 0 vnodes 208 6069 0 0 320 0 320 320 0 8 0 namei 1024 34457 0 34457 1 0 1 1 0 8 1 percpumem 16 30 0 0 1 0 1 1 0 8 0 vcpupl 1984 26 0 1 4 0 4 4 0 8 0 vmpool 552 30 0 5 2 0 2 2 0 8 0 scsiplug 64 3 0 3 2 2 0 1 0 8 0 scxspl 192 30304 0 30303 26 23 3 7 0 8 2 plimitpl 152 236 0 228 1 0 1 1 0 8 0 sigapl 432 2904 0 2888 3 1 2 3 0 8 0 futexpl 56 64429 0 64429 1 0 1 1 0 8 1 knotepl 112 771 0 752 3 2 1 3 0 8 0 kqueuepl 104 639 0 637 1 0 1 1 0 8 0 pipepl 112 2972 0 2953 13 11 2 2 0 8 1 fdescpl 488 2905 0 2888 3 0 3 3 0 8 0 filepl 152 27961 0 27856 22 17 5 14 0 8 0 lockfpl 104 1043 0 1042 1 0 1 1 0 8 0 lockfspl 48 349 0 348 1 0 1 1 0 8 0 sessionpl 112 37 0 26 1 0 1 1 0 8 0 pgrppl 48 85 0 74 1 0 1 1 0 8 0 ucredpl 96 2642 0 2632 1 0 1 1 0 8 0 zombiepl 144 2892 0 2892 1 0 1 1 0 8 1 processpl 896 2925 0 2892 4 0 4 4 0 8 0 procpl 632 9033 0 8988 5 0 5 5 0 8 1 srpgc 64 40 0 40 11 11 0 1 0 8 0 sosppl 128 41 0 41 11 10 1 1 0 8 1 sockpl 384 9839 0 9815 30 26 4 23 0 8 1 mcl64k 65536 73 0 0 9 3 6 9 0 8 0 mcl16k 16384 15 0 0 2 0 2 2 0 8 0 mcl12k 12288 24 0 0 2 0 2 2 0 8 0 mcl9k 9216 7 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 7 0 0 1 0 1 1 0 8 0 mcl2k 2048 166 0 0 19 2 17 19 0 8 0 mtagpl 80 51 0 0 1 0 1 1 0 8 0 mbufpl 256 874 0 0 51 0 51 51 0 8 0 bufpl 256 18024 0 10976 441 0 441 441 0 8 0 anonpl 16 358651 0 340084 138 50 88 93 0 124 9 amapchunkpl 152 20906 0 20788 37 28 9 19 0 158 3 amappl16 192 14747 0 13632 139 75 64 68 0 8 8 amappl15 184 504 0 503 1 0 1 1 0 8 0 amappl14 176 668 0 662 1 0 1 1 0 8 0 amappl13 168 297 0 295 3 2 1 1 0 8 0 amappl12 160 238 0 235 2 1 1 1 0 8 0 amappl11 152 288 0 272 1 0 1 1 0 8 0 amappl10 144 214 0 212 1 0 1 1 0 8 0 amappl9 136 1716 0 1708 1 0 1 1 0 8 0 amappl8 128 1257 0 1213 2 0 2 2 0 8 0 amappl7 120 307 0 299 1 0 1 1 0 8 0 amappl6 112 257 0 244 1 0 1 1 0 8 0 amappl5 104 512 0 498 1 0 1 1 0 8 0 amappl4 96 3320 0 3287 1 0 1 1 0 8 0 amappl3 88 707 0 699 1 0 1 1 0 8 0 amappl2 80 21518 0 21436 3 1 2 3 0 8 0 amappl1 72 75765 0 75298 25 15 10 20 0 8 0 amappl 80 9638 0 9582 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 17 0 17 1 1 0 1 0 8 0 aobjpl 64 133 0 4 3 0 3 3 0 8 0 uaddrrnd 24 2935 0 2888 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 2935 0 2888 1 0 1 1 0 8 0 vmmpekpl 168 30292 0 30256 4 1 3 3 0 8 0 vmmpepl 168 377390 0 374948 239 98 141 148 0 357 34 vmsppl 368 2904 0 2888 2 0 2 2 0 8 0 pdppl 4096 5877 0 5811 10 1 9 9 0 8 0 pvpl 32 996135 0 974327 312 104 208 215 0 265 26 pmappl 232 2934 0 2893 4 1 3 3 0 8 0 extentpl 40 41 0 26 1 0 1 1 0 8 0 phpool 112 676 0 24 19 0 19 19 0 8 0