panic: pool_cache_item_magic_check: mbufpl cpu free list modified: item addr 0xfffffd8067720700+16 0x0!=0x5881987ebd6e9aa6 Stopped at db_enter+0x18: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND *159952 34069 0 0 0x4000000 0 syz-executor.0 28349 5018 0 0 0 1 syz-executor.1 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(ffffffff82652290) at pool_cache_get+0x323 pool_cache_item_magic_check sys/kern/subr_pool.c:1789 [inline] pool_cache_get(ffffffff82652290) at pool_cache_get+0x323 sys/kern/subr_pool.c:1892 pool_get() at pool_get+0x91 sys/kern/subr_pool.c:572 m_gethdr(2,2) at m_gethdr+0x4c sys/kern/uipc_mbuf.c:283 ip_fragment(fffffd806d708800,ffff8000001732a8,5b4) at ip_fragment+0x13a sys/netinet/ip_output.c:682 ip_output(fffffd806d708800,0,fffffd806f6d0ea8,0,0,fffffd806f6d0e38) at ip_output+0xfc1 sys/netinet/ip_output.c:501 udp_output(fffffd806f6d0e38,fffffd806d708800,0,0) at udp_output+0x5af sys/netinet/udp_usrreq.c:1004 sosend(fffffd807e4b8050,0,ffff800024bb9230,0,0,0) at sosend+0x645 sys/kern/uipc_socket.c:524 sendit(ffff800020abe780,6,ffff800024bb9310,0,ffff800024bb93f0) at sendit+0x52b sys/kern/uipc_syscalls.c:662 sys_sendto(ffff800020abe780,ffff800024bb93a8,ffff800024bb93f0) at sys_sendto+0x80 sys/kern/uipc_syscalls.c:527 syscall(ffff800024bb9470) at syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:92 [inline] syscall(ffff800024bb9470) at syscall+0x4a4 sys/arch/amd64/amd64/trap.c:555 Xsyscall(6,0,ffffffffffffffd7,0,6,ca92af15010) at Xsyscall+0x128 end of kernel end trace frame: 0xcab795fbb00, 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{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 0xfffffd8067720700+16 0x0!=0x5881987ebd6e9aa6 ddb{0}> 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(ffffffff82652290) at pool_cache_get+0x323 pool_cache_item_magic_check sys/kern/subr_pool.c:1789 [inline] pool_cache_get(ffffffff82652290) at pool_cache_get+0x323 sys/kern/subr_pool.c:1892 pool_get() at pool_get+0x91 sys/kern/subr_pool.c:572 m_gethdr(2,2) at m_gethdr+0x4c sys/kern/uipc_mbuf.c:283 ip_fragment(fffffd806d708800,ffff8000001732a8,5b4) at ip_fragment+0x13a sys/netinet/ip_output.c:682 ip_output(fffffd806d708800,0,fffffd806f6d0ea8,0,0,fffffd806f6d0e38) at ip_output+0xfc1 sys/netinet/ip_output.c:501 udp_output(fffffd806f6d0e38,fffffd806d708800,0,0) at udp_output+0x5af sys/netinet/udp_usrreq.c:1004 sosend(fffffd807e4b8050,0,ffff800024bb9230,0,0,0) at sosend+0x645 sys/kern/uipc_socket.c:524 sendit(ffff800020abe780,6,ffff800024bb9310,0,ffff800024bb93f0) at sendit+0x52b sys/kern/uipc_syscalls.c:662 sys_sendto(ffff800020abe780,ffff800024bb93a8,ffff800024bb93f0) at sys_sendto+0x80 sys/kern/uipc_syscalls.c:527 syscall(ffff800024bb9470) at syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:92 [inline] syscall(ffff800024bb9470) at syscall+0x4a4 sys/arch/amd64/amd64/trap.c:555 Xsyscall(6,0,ffffffffffffffd7,0,6,ca92af15010) at Xsyscall+0x128 end of kernel end trace frame: 0xcab795fbb00, count: -13 ddb{0}> show registers rdi 0xffffffff812d2ac7 db_enter+0x17 rsi 0x77e3 __ALIGN_SIZE+0x67e3 rbp 0xffff800024bb8ca0 rbx 0xffff800024bb8d50 rdx 0x77e4 __ALIGN_SIZE+0x67e4 rcx 0xffff800023788000 rax 0xffff800023788000 r8 0xffffffff81c6670f kprintf+0x16f r9 0x1 r10 0x25 r11 0x259ac5fbf83a9fe r12 0x3000000008 r13 0xffff800024bb8cb0 r14 0x100 r15 0x1 rip 0xffffffff812d2ac8 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff800024bb8c90 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{0}> show proc PROC (syz-executor.0) pid=159952 stat=onproc flags process=0 proc=4000000 pri=86, usrpri=86, nice=20 forw=0xffffffffffffffff, list=0xffff800020abe290,0xffffffff8264fc48 process=0xffff800020adc700 user=0xffff800024bb4000, vmspace=0xfffffd807f00b8a0 estcpu=36, cpticks=1, pctcpu=0.0 user=0, sys=1, intr=0 ddb{0}> ps PID TID PPID UID S FLAGS WAIT COMMAND 34069 222749 25847 0 2 0 syz-executor.0 *34069 159952 25847 0 7 0x4000000 syz-executor.0 5018 28349 81953 0 7 0 syz-executor.1 5018 5841 81953 0 3 0x4000000 biowait syz-executor.1 25847 488735 7261 0 3 0x82 nanosleep syz-executor.0 39722 417932 1 0 3 0x100083 ttyin getty 81953 397453 7261 0 3 0x82 nanosleep syz-executor.1 67322 138859 0 0 3 0x14200 acct acct 36405 75036 0 0 3 0x14200 bored sosplice 7261 211658 99665 0 3 0x82 thrsleep syz-fuzzer 7261 483386 99665 0 3 0x4000082 nanosleep syz-fuzzer 7261 176882 99665 0 3 0x4000082 thrsleep syz-fuzzer 7261 29498 99665 0 3 0x4000082 thrsleep syz-fuzzer 7261 400686 99665 0 3 0x4000082 thrsleep syz-fuzzer 7261 101298 99665 0 3 0x4000082 kqread syz-fuzzer 7261 224080 99665 0 3 0x4000082 thrsleep syz-fuzzer 7261 223796 99665 0 3 0x4000082 thrsleep syz-fuzzer 7261 224022 99665 0 3 0x4000082 thrsleep syz-fuzzer 7261 4765 99665 0 3 0x4000082 thrsleep syz-fuzzer 99665 446132 57556 0 3 0x10008a pause ksh 57556 439342 58858 0 3 0x92 select sshd 58858 368693 1 0 3 0x80 select sshd 81398 287957 16764 74 3 0x100092 bpf pflogd 16764 251758 1 0 3 0x80 netio pflogd 42462 280348 92439 73 3 0x100090 kqread syslogd 92439 520395 1 0 3 0x100082 netio syslogd 49623 16032 1 77 3 0x100090 poll dhclient 1424 164074 1 0 3 0x80 poll dhclient 46976 487964 0 0 2 0x14200 zerothread 44759 33282 0 0 3 0x14200 aiodoned aiodoned 28904 281523 0 0 3 0x14200 syncer update 44729 124208 0 0 3 0x14200 cleaner cleaner 45123 125696 0 0 3 0x14200 reaper reaper 14631 504392 0 0 3 0x14200 pgdaemon pagedaemon 22993 199816 0 0 3 0x14200 bored crynlk 9951 130717 0 0 3 0x14200 bored crypto 40004 263593 0 0 3 0x40014200 acpi0 acpi0 89341 167980 0 0 3 0x40014200 idle1 17357 3750 0 0 3 0x14200 bored softnet 59531 268536 0 0 3 0x14200 bored systqmp 89796 408890 0 0 3 0x14200 bored systq 70548 418136 0 0 3 0x40014200 bored softclock 87723 337494 0 0 3 0x40014200 idle0 48118 374982 0 0 3 0x14200 bored smr 1 30605 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb{0}> show all locks Process 34069 (syz-executor.0) thread 0xffff800020abe780 (159952) exclusive rwlock netlock r = 0 (0xffffffff8246c0b8) #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 5018 (syz-executor.1) thread 0xffff800020abf650 (5841) exclusive rrwlock inode r = 0 (0xfffffd8079e3c4e0) #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 vn_write+0x11b sys/kern/vfs_vnops.c:402 #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{0}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim Kern Lim devbuf 9606 6823K 8439K 78643K 16392 0 0 pcb 13 8K 8K 78643K 217 0 0 rtable 94 8K 8K 78643K 901 0 0 ifaddr 80 16K 17K 78643K 263 0 0 counters 39 33K 33K 78643K 39 0 0 ioctlops 0 0K 4K 78643K 1539 0 0 iov 1 12K 28K 78643K 208 0 0 mount 1 1K 1K 78643K 1 0 0 vnodes 1225 77K 77K 78643K 2946 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 14 0 0 VM map 2 1K 1K 78643K 4 0 0 sem 12 0K 0K 78643K 232 0 0 dirhash 12 2K 2K 78643K 12 0 0 ACPI 1808 196K 290K 78643K 12765 0 0 file desc 6 17K 25K 78643K 1151 0 0 sigio 0 0K 0K 78643K 28 0 0 proc 60 63K 95K 78643K 949 0 0 subproc 32 2K 2K 78643K 187 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 100 0 0 in_multi 23 1K 2K 78643K 178 0 0 ether_multi 1 0K 0K 78643K 9 0 0 mrt 0 0K 0K 78643K 6 0 0 ISOFS mount 1 32K 32K 78643K 1 0 0 MSDOSFS mount 1 16K 16K 78643K 1 0 0 ttys 72 318K 318K 78643K 72 0 0 exec 0 0K 1K 78643K 413 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 115 22K 31K 78643K 4976 0 0 UVM aobj 77 3K 3K 78643K 82 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 192 0 0 NDP 19 0K 0K 78643K 81 0 0 temp 221 3556K 3624K 78643K 27692 0 0 kqueue 0 0K 0K 78643K 5 0 0 SYN cache 2 16K 16K 78643K 2 0 0 ddb{0}> show all pools Name Size Requests Fail Releases Pgreq Pgrel Npage Hiwat Minpg Maxpg Idle arp 64 28 0 24 1 0 1 1 0 8 0 plcache 128 20 0 0 1 0 1 1 0 8 0 rtpcb 80 85 0 83 1 0 1 1 0 8 0 rtentry 112 172 0 138 2 0 2 2 0 8 0 unpcb 120 1117 0 1101 1 0 1 1 0 8 0 syncache 264 6 0 6 3 3 0 1 0 8 0 tcpqe 32 5053 0 5053 1 1 0 1 0 8 0 tcpcb 544 328 0 324 1 0 1 1 0 8 0 inpcb 280 1229 0 1221 5 4 1 2 0 8 0 rttmr 72 2 0 2 2 2 0 1 0 8 0 nd6 48 23 0 21 1 0 1 1 0 8 0 pkpcb 40 4 0 4 2 1 1 1 0 8 1 ppxss 1128 27 0 27 6 5 1 1 0 8 1 pffrag 232 24 0 24 5 5 0 1 0 482 0 pffrnode 88 24 0 24 5 5 0 1 0 8 0 pffrent 40 521 0 521 5 5 0 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 79 0 52 1 0 1 1 0 8 0 pfstkey 112 79 0 52 2 0 2 2 0 8 0 pfstate 328 79 0 52 4 0 4 4 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 256 719 0 547 20 5 15 15 0 8 4 art_table 32 720 0 547 2 0 2 2 0 8 0 art_node 16 168 0 137 1 0 1 1 0 8 0 sysvmsgpl 40 31 0 11 1 0 1 1 0 8 0 semapl 112 230 0 220 1 0 1 1 0 8 0 shmpl 112 80 0 5 3 0 3 3 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino1pl 128 3192 0 1794 46 0 46 46 0 8 0 ffsino 272 3192 0 1794 94 0 94 94 0 8 0 nchpl 144 5091 0 3479 61 0 61 61 0 8 0 uvmvnodes 72 4690 0 0 86 0 86 86 0 8 0 vnodes 208 4690 0 0 247 0 247 247 0 8 0 namei 1024 17456 0 17456 3 2 1 1 0 8 1 percpumem 16 30 0 0 1 0 1 1 0 8 0 vmpool 552 2 0 2 1 1 0 1 0 8 0 scsiplug 64 1 0 1 1 1 0 1 0 8 0 scxspl 192 15902 0 15901 18 17 1 7 0 8 0 plimitpl 152 101 0 93 1 0 1 1 0 8 0 sigapl 432 1325 0 1309 3 1 2 3 0 8 0 futexpl 56 23564 0 23564 1 0 1 1 0 8 1 knotepl 112 330 0 311 1 0 1 1 0 8 0 kqueuepl 104 257 0 255 1 0 1 1 0 8 0 pipepl 112 1464 0 1445 10 8 2 2 0 8 1 fdescpl 488 1326 0 1309 3 0 3 3 0 8 0 filepl 152 11625 0 11514 16 9 7 7 0 8 2 lockfpl 104 337 0 335 1 0 1 1 0 8 0 lockfspl 48 116 0 114 1 0 1 1 0 8 0 sessionpl 112 28 0 17 1 0 1 1 0 8 0 pgrppl 48 46 0 35 1 0 1 1 0 8 0 ucredpl 96 1586 0 1577 1 0 1 1 0 8 0 zombiepl 144 1309 0 1309 3 2 1 1 0 8 1 processpl 896 1343 0 1309 4 0 4 4 0 8 0 procpl 632 3771 0 3726 7 2 5 5 0 8 0 srpgc 64 20 0 20 6 5 1 1 0 8 1 sosppl 128 11 0 11 5 5 0 1 0 8 0 sockpl 384 2443 0 2417 12 8 4 5 0 8 1 mcl64k 65536 13 0 0 2 0 2 2 0 8 0 mcl16k 16384 12 0 0 2 0 2 2 0 8 0 mcl12k 12288 17 0 0 2 0 2 2 0 8 0 mcl9k 9216 3 0 0 1 0 1 1 0 8 0 mcl8k 8192 17 0 0 3 0 3 3 0 8 0 mcl4k 4096 10 0 0 2 0 2 2 0 8 0 mcl2k2 2112 16 0 0 2 0 2 2 0 8 0 mcl2k 2048 154 0 0 18 0 18 18 0 8 0 mtagpl 80 27 0 0 1 0 1 1 0 8 0 mbufpl 256 548 0 0 29 0 29 29 0 8 0 bufpl 256 9581 0 2533 441 0 441 441 0 8 0 anonpl 16 190826 0 174902 115 37 78 85 0 124 5 amapchunkpl 152 9303 0 9181 25 19 6 13 0 158 0 amappl16 192 7931 0 6985 104 50 54 59 0 8 6 amappl15 184 327 0 327 2 1 1 1 0 8 1 amappl14 176 111 0 109 2 1 1 1 0 8 0 amappl13 168 119 0 117 2 1 1 1 0 8 0 amappl12 160 465 0 464 1 0 1 1 0 8 0 amappl11 152 109 0 91 1 0 1 1 0 8 0 amappl10 144 227 0 223 1 0 1 1 0 8 0 amappl9 136 738 0 732 1 0 1 1 0 8 0 amappl8 128 288 0 259 3 1 2 2 0 8 0 amappl7 120 274 0 264 1 0 1 1 0 8 0 amappl6 112 95 0 83 1 0 1 1 0 8 0 amappl5 104 651 0 634 1 0 1 1 0 8 0 amappl4 96 1452 0 1420 1 0 1 1 0 8 0 amappl3 88 368 0 362 1 0 1 1 0 8 0 amappl2 80 9510 0 9427 4 2 2 3 0 8 0 amappl1 72 40243 0 39789 26 16 10 20 0 8 0 amappl 80 4181 0 4138 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 81 0 5 2 0 2 2 0 8 0 uaddrrnd 24 1328 0 1309 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 1328 0 1309 1 0 1 1 0 8 0 vmmpekpl 168 15203 0 15163 3 0 3 3 0 8 0 vmmpepl 168 177404 0 175213 208 81 127 127 0 357 31 vmsppl 368 1325 0 1309 2 0 2 2 0 8 0 pdppl 4096 2663 0 2622 7 1 6 6 0 8 0 pvpl 32 502551 0 483338 255 68 187 199 0 265 19 pmappl 232 1327 0 1311 3 2 1 2 0 8 0 extentpl 40 41 0 26 1 0 1 1 0 8 0 phpool 112 632 0 11 18 0 18 18 0 8 0