panic: pool_cache_item_magic_check: mbufpl cpu free list modified: item addr 0xfffffd806907e400+16 0x0!=0x528c94232f733d28 Stopped at db_enter+0x18: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND 346643 94323 0 0 0 1 syz-executor.1 *162556 94323 0 0 0x4000000 0 syz-executor.1 db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:398 panic(ffffffff8240ef1a) at panic+0x164 sys/kern/subr_prf.c:218 pool_cache_get(ffffffff82933910) at pool_cache_get+0x323 pool_cache_item_magic_check sys/kern/subr_pool.c:1781 [inline] pool_cache_get(ffffffff82933910) at pool_cache_get+0x323 sys/kern/subr_pool.c:1884 pool_get(ffffffff82933910,2) 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(fffffd807f00d700,ffff80000017c2a8,5b4) at ip_fragment+0x13a sys/netinet/ip_output.c:680 ip_output(fffffd807f00d700,0,fffffd806f6699b0,0,0,fffffd806f669940) at ip_output+0xfd7 sys/netinet/ip_output.c:499 udp_output(fffffd806f669940,fffffd807f00d700,0,0) at udp_output+0x5af sys/netinet/udp_usrreq.c:1017 sosend(fffffd806c9b24c0,0,ffff800020edbf10,0,0,0) at sosend+0x671 sys/kern/uipc_socket.c:555 sendit(ffff800021f82790,6,ffff800020edbff0,0,ffff800020edc0d0) at sendit+0x52b sys/kern/uipc_syscalls.c:657 sys_sendto(ffff800021f82790,ffff800020edc088,ffff800020edc0d0) at sys_sendto+0x80 sys/kern/uipc_syscalls.c:522 syscall(ffff800020edc150) at syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:102 [inline] syscall(ffff800020edc150) at syscall+0x4a4 sys/arch/amd64/amd64/trap.c:570 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x54fdd2bcb00, 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 0xfffffd806907e400+16 0x0!=0x528c94232f733d28 ddb{0}> trace db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:398 panic(ffffffff8240ef1a) at panic+0x164 sys/kern/subr_prf.c:218 pool_cache_get(ffffffff82933910) at pool_cache_get+0x323 pool_cache_item_magic_check sys/kern/subr_pool.c:1781 [inline] pool_cache_get(ffffffff82933910) at pool_cache_get+0x323 sys/kern/subr_pool.c:1884 pool_get(ffffffff82933910,2) 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(fffffd807f00d700,ffff80000017c2a8,5b4) at ip_fragment+0x13a sys/netinet/ip_output.c:680 ip_output(fffffd807f00d700,0,fffffd806f6699b0,0,0,fffffd806f669940) at ip_output+0xfd7 sys/netinet/ip_output.c:499 udp_output(fffffd806f669940,fffffd807f00d700,0,0) at udp_output+0x5af sys/netinet/udp_usrreq.c:1017 sosend(fffffd806c9b24c0,0,ffff800020edbf10,0,0,0) at sosend+0x671 sys/kern/uipc_socket.c:555 sendit(ffff800021f82790,6,ffff800020edbff0,0,ffff800020edc0d0) at sendit+0x52b sys/kern/uipc_syscalls.c:657 sys_sendto(ffff800021f82790,ffff800020edc088,ffff800020edc0d0) at sys_sendto+0x80 sys/kern/uipc_syscalls.c:522 syscall(ffff800020edc150) at syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:102 [inline] syscall(ffff800020edc150) at syscall+0x4a4 sys/arch/amd64/amd64/trap.c:570 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x54fdd2bcb00, count: -13 ddb{0}> show registers rdi 0 rsi 0x1 rbp 0xffff800020edb980 rbx 0xffff800020edba30 rdx 0x8b rcx 0x2 rax 0x1 r8 0xffff800020edb940 r9 0xffffffff8108ddff kprintf+0x16f r10 0x1 r11 0xdef25a2ade86dd28 r12 0x3000000008 r13 0xffff800020edb990 r14 0x100 r15 0x1 rip 0xffffffff822b91e8 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff800020edb970 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{0}> show proc PROC (syz-executor.1) pid=162556 stat=onproc flags process=0 proc=4000000 pri=32, usrpri=70, nice=20 forw=0xffffffffffffffff, list=0xffff800021f83b50,0xffffffff828cde18 process=0xffff800021f687e0 user=0xffff800020ed7000, vmspace=0xfffffd807effea10 estcpu=36, cpticks=1, pctcpu=0.0 user=0, sys=1, intr=0 ddb{0}> ps PID TID PPID UID S FLAGS WAIT COMMAND 94323 346643 21376 0 7 0 syz-executor.1 *94323 162556 21376 0 7 0x4000000 syz-executor.1 21376 458040 75578 0 3 0x82 nanosleep syz-executor.1 47365 473406 75578 0 3 0x82 piperd syz-executor.0 43511 424489 0 0 3 0x14280 nfsidl nfsio 29915 22004 0 0 3 0x14280 nfsidl nfsio 84087 292709 0 0 3 0x14280 nfsidl nfsio 43968 239770 0 0 3 0x14280 nfsidl nfsio 38966 394925 0 0 3 0x14280 nfsidl nfsio 82593 256526 0 0 3 0x14280 nfsidl nfsio 90985 402280 0 0 3 0x14280 nfsidl nfsio 20310 501893 0 0 3 0x14280 nfsidl nfsio 11448 469769 0 0 3 0x14280 nfsidl nfsio 22765 422412 0 0 3 0x14280 nfsidl nfsio 71003 271703 0 0 3 0x14280 nfsidl nfsio 9399 495027 0 0 3 0x14280 nfsidl nfsio 91827 196588 0 0 3 0x14280 nfsidl nfsio 9249 127856 0 0 3 0x14280 nfsidl nfsio 5636 468947 0 0 3 0x14280 nfsidl nfsio 31725 432964 0 0 3 0x14280 nfsidl nfsio 57936 396476 0 0 3 0x14280 nfsidl nfsio 73336 159584 0 0 3 0x14280 nfsidl nfsio 85845 228032 0 0 3 0x14280 nfsidl nfsio 5923 214248 0 0 3 0x14280 nfsidl nfsio 75578 21595 73863 0 2 0x2 syz-fuzzer 75578 498855 73863 0 3 0x4000082 nanosleep syz-fuzzer 75578 126455 73863 0 3 0x4000082 thrsleep syz-fuzzer 75578 402133 73863 0 3 0x4000082 kqread syz-fuzzer 75578 163037 73863 0 3 0x4000082 thrsleep syz-fuzzer 75578 248546 73863 0 3 0x4000082 thrsleep syz-fuzzer 75578 315740 73863 0 3 0x4000082 thrsleep syz-fuzzer 75578 334157 73863 0 3 0x4000082 thrsleep syz-fuzzer 73863 192183 54435 0 3 0x10008a pause ksh 54435 179085 70821 0 3 0x92 select sshd 71948 127670 1 0 3 0x100083 ttyin getty 70821 172024 1 0 3 0x80 select sshd 80816 476069 81274 74 3 0x100092 bpf pflogd 81274 301980 1 0 3 0x80 netio pflogd 81954 129233 38105 73 3 0x100090 kqread syslogd 38105 16835 1 0 3 0x100082 netio syslogd 87570 94908 1 77 3 0x100090 poll dhclient 66357 260440 1 0 3 0x80 poll dhclient 55876 127199 0 0 3 0x14200 bored smr 43724 290986 0 0 2 0x14200 zerothread 46456 436523 0 0 3 0x14200 aiodoned aiodoned 34501 334671 0 0 3 0x14200 syncer update 65590 150752 0 0 3 0x14200 cleaner cleaner 72600 164210 0 0 3 0x14200 reaper reaper 35675 159000 0 0 3 0x14200 pgdaemon pagedaemon 87234 374513 0 0 3 0x14200 bored crynlk 52340 384888 0 0 3 0x14200 bored crypto 30773 107233 0 0 3 0x40014200 acpi0 acpi0 57921 54513 0 0 3 0x40014200 idle1 75309 231758 0 0 3 0x14200 bored softnet 86398 222062 0 0 3 0x14200 bored systqmp 20637 509699 0 0 3 0x14200 bored systq 57673 274463 0 0 3 0x40014200 bored softclock 58555 203397 0 0 3 0x40014200 idle0 1 135478 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb{0}> show all locks Process 94323 (syz-executor.1) thread 0xffff800021f82790 (162556) exclusive rwlock netlock r = 0 (0xffffffff827713e0) #0 witness_lock+0x4c7 stacktrace_save sys/sys/stacktrace.h:36 [inline] #0 witness_lock+0x4c7 sys/kern/subr_witness.c:1164 #1 solock+0x5a sys/kern/uipc_socket2.c:282 #2 sosend+0x559 sys/kern/uipc_socket.c:543 #3 sendit+0x52b sys/kern/uipc_syscalls.c:657 #4 sys_sendto+0x80 sys/kern/uipc_syscalls.c:522 #5 syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:102 [inline] #5 syscall+0x4a4 sys/arch/amd64/amd64/trap.c:570 #6 Xsyscall+0x128 ddb{0}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim devbuf 9487 6403K 6787K 78643K 10885 0 pcb 13 8K 8K 78643K 76 0 rtable 110 5K 6K 78643K 398 0 ifaddr 57 13K 13K 78643K 113 0 counters 43 33K 34K 78643K 59 0 ioctlops 0 0K 4K 78643K 1524 0 iov 0 0K 16K 78643K 28 0 mount 1 1K 1K 78643K 1 0 vnodes 1222 77K 77K 78643K 1364 0 UFS quota 1 32K 32K 78643K 1 0 UFS mount 5 36K 36K 78643K 5 0 shm 2 1K 5K 78643K 3 0 VM map 2 1K 1K 78643K 2 0 sem 12 1K 1K 78643K 18 0 dirhash 12 2K 2K 78643K 12 0 ACPI 1824 197K 290K 78643K 13058 0 file desc 5 13K 25K 78643K 394 0 sigio 0 0K 0K 78643K 3 0 proc 61 63K 95K 78643K 541 0 subproc 32 2K 2K 78643K 68 0 NFS srvsock 1 0K 0K 78643K 1 0 NFS daemon 1 16K 16K 78643K 1 0 ip_moptions 0 0K 0K 78643K 24 0 in_multi 33 2K 2K 78643K 99 0 ether_multi 1 0K 0K 78643K 7 0 mrt 0 0K 0K 78643K 4 0 ISOFS mount 1 32K 32K 78643K 1 0 MSDOSFS mount 1 16K 16K 78643K 1 0 ttys 55 254K 254K 78643K 55 0 exec 0 0K 1K 78643K 251 0 pagedep 1 8K 8K 78643K 1 0 inodedep 1 32K 32K 78643K 1 0 newblk 1 0K 0K 78643K 1 0 VM swap 7 26K 26K 78643K 7 0 UVM amap 160 25K 41K 78643K 2234 0 UVM aobj 14 2K 2K 78643K 14 0 memdesc 1 4K 4K 78643K 1 0 crypto data 1 1K 1K 78643K 1 0 ip6_options 0 0K 0K 78643K 47 0 NDP 8 0K 0K 78643K 27 0 temp 93 3866K 3930K 78643K 6212 0 kqueue 3 4K 16K 78643K 36 0 SYN cache 2 16K 16K 78643K 2 0 ddb{0}> show all pools Name Size Requests Fail Releases Pgreq Pgrel Npage Hiwat Minpg Maxpg Idle arp 64 12 0 6 1 0 1 1 0 8 0 plcache 128 20 0 0 1 0 1 1 0 8 0 rtpcb 88 532 0 530 1 0 1 1 0 8 0 rtentry 112 79 0 38 2 0 2 2 0 8 0 unpcb 120 216 0 205 1 0 1 1 0 8 0 syncache 272 6 0 6 2 2 0 1 0 8 0 tcpqe 32 107 0 107 1 1 0 1 0 8 0 tcpcb 592 104 0 100 2 0 2 2 0 8 1 inpcb 296 363 0 355 2 0 2 2 0 8 1 rttmr 72 2 0 2 2 1 1 1 0 8 1 nd6 48 15 0 11 1 0 1 1 0 8 0 ppxss 1136 3 0 3 1 0 1 1 0 8 1 pffrent 40 2 0 2 1 1 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 pfrktable 1344 14 0 10 1 0 1 1 0 8 0 pfstitem 24 15 0 7 1 0 1 1 0 8 0 pfstkey 112 15 0 7 1 0 1 1 0 8 0 pfstate 328 15 0 7 2 0 2 2 0 8 0 pfrule 1360 29 0 19 2 1 1 2 0 8 0 art_heap8 4096 1 0 0 1 0 1 1 0 8 0 art_heap4 256 302 0 130 12 0 12 12 0 8 0 art_table 32 303 0 130 2 0 2 2 0 8 0 art_node 16 78 0 40 1 0 1 1 0 8 0 sysvmsgpl 40 18 0 9 1 0 1 1 0 8 0 semupl 112 3 0 3 1 1 0 1 0 8 0 semapl 112 11 0 1 1 0 1 1 0 8 0 shmpl 112 11 0 0 1 0 1 1 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino2pl 256 1859 0 454 88 0 88 88 0 8 0 ffsino 272 1859 0 454 94 0 94 94 0 8 0 nchpl 144 2564 0 971 60 0 60 60 0 8 0 uvmvnodes 72 2007 0 0 37 0 37 37 0 8 0 vnodes 208 2007 0 0 106 0 106 106 0 8 0 namei 1024 7035 0 7035 1 0 1 1 0 8 1 percpumem 16 40 0 8 1 0 1 1 0 8 0 pfiaddrpl 120 5 0 3 2 1 1 1 0 8 0 scsiplug 72 1 0 1 1 1 0 1 0 8 0 scxspl 200 7667 0 7667 8 7 1 7 0 8 1 plimitpl 152 27 0 19 1 0 1 1 0 8 0 sigapl 424 623 0 572 6 0 6 6 0 8 0 futexpl 56 5150 0 5150 1 0 1 1 0 8 1 knotepl 112 119 0 99 1 0 1 1 0 8 0 kqueuepl 152 58 0 54 1 0 1 1 0 8 0 pipepl 304 116 0 105 2 0 2 2 0 8 0 fdescpl 496 588 0 572 4 1 3 3 0 8 1 filepl 152 3325 0 3221 5 0 5 5 0 8 0 lockfpl 104 73 0 72 1 0 1 1 0 8 0 lockfspl 48 24 0 23 1 0 1 1 0 8 0 sessionpl 120 20 0 9 1 0 1 1 0 8 0 pgrppl 48 25 0 14 1 0 1 1 0 8 0 ucredpl 96 257 0 248 1 0 1 1 0 8 0 zombiepl 144 572 0 572 1 0 1 1 0 8 1 processpl 1008 623 0 572 7 0 7 7 0 8 0 procpl 632 1337 0 1278 6 0 6 6 0 8 0 srpgc 72 2 0 2 1 1 0 1 0 8 0 sockpl 400 1113 0 1092 4 0 4 4 0 8 1 mcl64k 65536 7 0 0 1 0 1 1 0 8 0 mcl16k 16384 2 0 0 1 0 1 1 0 8 0 mcl12k 12288 5 0 0 1 0 1 1 0 8 0 mcl9k 9216 1 0 0 1 0 1 1 0 8 0 mcl8k 8192 5 0 0 1 0 1 1 0 8 0 mcl4k 4096 9 0 0 2 0 2 2 0 8 0 mcl2k2 2112 2 0 0 1 0 1 1 0 8 0 mcl2k 2048 334 0 0 41 0 41 41 0 8 0 mtagpl 96 15 0 0 1 0 1 1 0 8 0 mbufpl 256 347 0 0 21 0 21 21 0 8 0 mbufpl: pool(0xffffffff82933910:mbufpl): free list modified: page 0xfffffd806907e000; item ordinal 0; addr 0xfffffd806907e200 (p 0xfffffd80691fa000); offset 0x0=0x0 pool(mbufpl): free list modified: page 0xfffffd806907e000; item ordinal 0; addr 0xfffffd806907e200 (p 0xfffffd80691fa000); offset 0x0=0x0 mbufpl: pool(0xffffffff82933910:mbufpl): page inconsistency: page 0xfffffd806907e000; item ordinal 1; addr 0x14538e9ca1dd5d84 bufpl 280 4070 0 127 282 0 282 282 0 8 0 anonpl 16 75136 0 57266 84 8 76 83 0 124 0 amapchunkpl 152 4596 0 4277 33 6 27 27 0 158 13 amappl16 192 2200 0 1365 44 2 42 44 0 8 0 amappl15 184 1 0 0 1 0 1 1 0 8 0 amappl14 176 108 0 105 2 1 1 1 0 8 0 amappl13 168 267 0 262 1 0 1 1 0 8 0 amappl12 160 247 0 242 1 0 1 1 0 8 0 amappl11 152 61 0 46 1 0 1 1 0 8 0 amappl10 144 23 0 17 1 0 1 1 0 8 0 amappl9 136 382 0 379 1 0 1 1 0 8 0 amappl8 128 372 0 340 2 0 2 2 0 8 0 amappl7 120 129 0 117 1 0 1 1 0 8 0 amappl6 112 34 0 27 1 0 1 1 0 8 0 amappl5 104 251 0 236 1 0 1 1 0 8 0 amappl4 96 741 0 714 1 0 1 1 0 8 0 amappl3 88 458 0 447 1 0 1 1 0 8 0 amappl2 80 3620 0 3551 2 0 2 2 0 8 0 amappl1 72 26106 0 25667 23 13 10 18 0 8 0 amappl 80 1660 0 1576 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 13 0 0 1 0 1 1 0 8 0 uaddrrnd 24 588 0 572 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 588 0 572 1 0 1 1 0 8 0 vmmpekpl 168 8299 0 8261 2 0 2 2 0 8 0 vmmpepl 168 82522 0 80487 131 17 114 122 0 357 25 vmsppl 368 587 0 572 2 0 2 2 0 8 0 pdppl 4096 1183 0 1144 6 1 5 6 0 8 0 pvpl 32 240634 0 219490 200 14 186 200 0 265 9 pmappl 232 587 0 572 2 1 1 2 0 8 0 extentpl 40 53 0 36 1 0 1 1 0 8 0 phpool 112 284 0 6 8 0 8 8 0 8 0 ddb{0}> machine ddbcpu 0 Invalid cpu 0 ddb{0}> trace db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:398 panic(ffffffff8240ef1a) at panic+0x164 sys/kern/subr_prf.c:218 pool_cache_get(ffffffff82933910) at pool_cache_get+0x323 pool_cache_item_magic_check sys/kern/subr_pool.c:1781 [inline] pool_cache_get(ffffffff82933910) at pool_cache_get+0x323 sys/kern/subr_pool.c:1884 pool_get(ffffffff82933910,2) 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(fffffd807f00d700,ffff80000017c2a8,5b4) at ip_fragment+0x13a sys/netinet/ip_output.c:680 ip_output(fffffd807f00d700,0,fffffd806f6699b0,0,0,fffffd806f669940) at ip_output+0xfd7 sys/netinet/ip_output.c:499 udp_output(fffffd806f669940,fffffd807f00d700,0,0) at udp_output+0x5af sys/netinet/udp_usrreq.c:1017 sosend(fffffd806c9b24c0,0,ffff800020edbf10,0,0,0) at sosend+0x671 sys/kern/uipc_socket.c:555 sendit(ffff800021f82790,6,ffff800020edbff0,0,ffff800020edc0d0) at sendit+0x52b sys/kern/uipc_syscalls.c:657 sys_sendto(ffff800021f82790,ffff800020edc088,ffff800020edc0d0) at sys_sendto+0x80 sys/kern/uipc_syscalls.c:522 syscall(ffff800020edc150) at syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:102 [inline] syscall(ffff800020edc150) at syscall+0x4a4 sys/arch/amd64/amd64/trap.c:570 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x54fdd2bcb00, count: -13 ddb{0}> machine ddbcpu 1 Stopped at x86_ipi_db+0x1a: addq $0x8,%rsp x86_ipi_db(ffff800020d70ff0) at x86_ipi_db+0x1a sys/arch/amd64/amd64/db_interface.c:352 x86_ipi_handler() at x86_ipi_handler+0xc6 sys/arch/amd64/amd64/ipi.c:106 Xresume_lapic_ipi() at Xresume_lapic_ipi+0x23 end of kernel end trace frame: 0x7f7ffffd3040, count: 12 ddb{1}> trace x86_ipi_db(ffff800020d70ff0) at x86_ipi_db+0x1a sys/arch/amd64/amd64/db_interface.c:352 x86_ipi_handler() at x86_ipi_handler+0xc6 sys/arch/amd64/amd64/ipi.c:106 Xresume_lapic_ipi() at Xresume_lapic_ipi+0x23 end of kernel end trace frame: 0x7f7ffffd3040, count: -3