panic: pool_cache_item_magic_check: mbufpl cpu free list modified: item addr 0xfffffd807cca0100+24 0x137d291787598a08!=0x137d2997e34fc208 Stopped at db_enter+0x18: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND *480872 47210 0 0 0x4000000 0 syz-executor.1 360776 74107 0 0x2 0x4000000 1 syz-fuzzer db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:398 panic(ffffffff8240acfd) at panic+0x164 sys/kern/subr_prf.c:218 pool_cache_get(ffffffff828ce6d0) at pool_cache_get+0x323 pool_cache_item_magic_check sys/kern/subr_pool.c:1781 [inline] pool_cache_get(ffffffff828ce6d0) at pool_cache_get+0x323 sys/kern/subr_pool.c:1884 pool_get(ffffffff828ce6d0,2) at pool_get+0x91 sys/kern/subr_pool.c:572 m_gethdr(2,2) at m_gethdr+0x4c sys/kern/uipc_mbuf.c:283 ip6_fragment(fffffd806ca14b00,28,11,500) at ip6_fragment+0xec sys/netinet6/ip6_output.c:810 ip6_output(fffffd806ca14b00,0,fffffd8077625ae0,0,0,fffffd8077625a70) at ip6_output+0x1ba2 sys/netinet6/ip6_output.c:736 udp6_output(fffffd8077625a70,fffffd8063efe600,0,0) at udp6_output+0x36a sys/netinet6/udp6_output.c:236 sosend(fffffd8077624978,0,ffff800021fab5e0,0,0,8a) at sosend+0x671 sys/kern/uipc_socket.c:555 sendit(ffff800021f942a0,6,ffff800021fab6c0,a,ffff800021fab7a0) at sendit+0x52b sys/kern/uipc_syscalls.c:657 sys_sendto(ffff800021f942a0,ffff800021fab758,ffff800021fab7a0) at sys_sendto+0x80 sys/kern/uipc_syscalls.c:522 syscall(ffff800021fab820) at syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:102 [inline] syscall(ffff800021fab820) at syscall+0x4a4 sys/arch/amd64/amd64/trap.c:570 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0xeaaf7cec810, 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 0xfffffd807cca0100+24 0x137d291787598a08!=0x137d2997e34fc208 ddb{0}> trace db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:398 panic(ffffffff8240acfd) at panic+0x164 sys/kern/subr_prf.c:218 pool_cache_get(ffffffff828ce6d0) at pool_cache_get+0x323 pool_cache_item_magic_check sys/kern/subr_pool.c:1781 [inline] pool_cache_get(ffffffff828ce6d0) at pool_cache_get+0x323 sys/kern/subr_pool.c:1884 pool_get(ffffffff828ce6d0,2) at pool_get+0x91 sys/kern/subr_pool.c:572 m_gethdr(2,2) at m_gethdr+0x4c sys/kern/uipc_mbuf.c:283 ip6_fragment(fffffd806ca14b00,28,11,500) at ip6_fragment+0xec sys/netinet6/ip6_output.c:810 ip6_output(fffffd806ca14b00,0,fffffd8077625ae0,0,0,fffffd8077625a70) at ip6_output+0x1ba2 sys/netinet6/ip6_output.c:736 udp6_output(fffffd8077625a70,fffffd8063efe600,0,0) at udp6_output+0x36a sys/netinet6/udp6_output.c:236 sosend(fffffd8077624978,0,ffff800021fab5e0,0,0,8a) at sosend+0x671 sys/kern/uipc_socket.c:555 sendit(ffff800021f942a0,6,ffff800021fab6c0,a,ffff800021fab7a0) at sendit+0x52b sys/kern/uipc_syscalls.c:657 sys_sendto(ffff800021f942a0,ffff800021fab758,ffff800021fab7a0) at sys_sendto+0x80 sys/kern/uipc_syscalls.c:522 syscall(ffff800021fab820) at syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:102 [inline] syscall(ffff800021fab820) at syscall+0x4a4 sys/arch/amd64/amd64/trap.c:570 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0xeaaf7cec810, count: -13 ddb{0}> show registers rdi 0 rsi 0x1 rbp 0xffff800021faaf30 rbx 0xffff800021faafe0 rdx 0x8b rcx 0x2 rax 0x1 r8 0xffff800021faaef0 r9 0xffffffff814bc41f kprintf+0x16f r10 0x1 r11 0x991a497d814a3802 r12 0x3000000008 r13 0xffff800021faaf40 r14 0x100 r15 0x1 rip 0xffffffff81c991c8 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff800021faaf20 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{0}> show proc PROC (syz-executor.1) pid=480872 stat=onproc flags process=0 proc=4000000 pri=32, usrpri=86, nice=20 forw=0xffffffffffffffff, list=0xffff800021f94790,0xffffffff828c88f8 process=0xffff800021f807e0 user=0xffff800021fa6000, vmspace=0xfffffd807efff730 estcpu=36, cpticks=2, pctcpu=0.0 user=0, sys=2, intr=0 ddb{0}> ps PID TID PPID UID S FLAGS WAIT COMMAND 47210 275108 56268 0 2 0 syz-executor.1 47210 105045 56268 0 2 0x4000000 syz-executor.1 47210 455515 56268 0 2 0x4000000 syz-executor.1 *47210 480872 56268 0 7 0x4000000 syz-executor.1 77189 115661 0 0 3 0x14200 bored sosplice 56268 268836 74107 0 3 0x82 nanosleep syz-executor.1 98859 184323 0 0 3 0x14280 nfsidl nfsio 32412 146595 0 0 3 0x14280 nfsidl nfsio 22550 321303 0 0 3 0x14280 nfsidl nfsio 83158 473004 0 0 3 0x14280 nfsidl nfsio 8117 491867 0 0 3 0x14280 nfsidl nfsio 17957 414838 0 0 3 0x14280 nfsidl nfsio 44201 303521 0 0 3 0x14280 nfsidl nfsio 15284 368239 0 0 3 0x14280 nfsidl nfsio 29978 427199 0 0 3 0x14280 nfsidl nfsio 32534 393610 0 0 3 0x14280 nfsidl nfsio 48357 245232 0 0 3 0x14280 nfsidl nfsio 276 63686 0 0 3 0x14280 nfsidl nfsio 41084 399687 0 0 3 0x14280 nfsidl nfsio 34342 287510 0 0 3 0x14280 nfsidl nfsio 3394 47122 0 0 3 0x14280 nfsidl nfsio 56106 253768 0 0 3 0x14280 nfsidl nfsio 13886 104164 0 0 3 0x14280 nfsidl nfsio 15746 230990 0 0 3 0x14280 nfsidl nfsio 90939 190687 0 0 3 0x14280 nfsidl nfsio 92882 388127 0 0 3 0x14280 nfsidl nfsio 45012 5327 74107 0 3 0x82 piperd syz-executor.0 74107 263160 16078 0 3 0x82 thrsleep syz-fuzzer 74107 399843 16078 0 3 0x4000082 nanosleep syz-fuzzer 74107 360776 16078 0 7 0x4000002 syz-fuzzer 74107 441321 16078 0 3 0x4000082 thrsleep syz-fuzzer 74107 238196 16078 0 3 0x4000082 thrsleep syz-fuzzer 74107 307720 16078 0 3 0x4000082 thrsleep syz-fuzzer 74107 458171 16078 0 3 0x4000082 thrsleep syz-fuzzer 74107 403622 16078 0 3 0x4000082 kqread syz-fuzzer 16078 517216 79572 0 3 0x10008a pause ksh 79572 427226 4711 0 3 0x92 select sshd 72775 79000 1 0 3 0x100083 ttyin getty 4711 160732 1 0 3 0x80 select sshd 27510 231450 93875 74 3 0x100092 bpf pflogd 93875 380070 1 0 3 0x80 netio pflogd 28849 257125 45334 73 3 0x100090 kqread syslogd 45334 117781 1 0 3 0x100082 netio syslogd 90049 518559 1 77 3 0x100090 poll dhclient 16157 335832 1 0 3 0x80 poll dhclient 58489 453659 0 0 3 0x14200 bored smr 38045 513541 0 0 2 0x14200 zerothread 66016 91038 0 0 3 0x14200 aiodoned aiodoned 81014 377461 0 0 3 0x14200 syncer update 82191 412962 0 0 3 0x14200 cleaner cleaner 86149 389319 0 0 3 0x14200 reaper reaper 77055 495801 0 0 3 0x14200 pgdaemon pagedaemon 25743 84363 0 0 3 0x14200 bored crynlk 20395 143145 0 0 3 0x14200 bored crypto 55101 5871 0 0 3 0x40014200 acpi0 acpi0 97765 126148 0 0 3 0x40014200 idle1 49010 225905 0 0 3 0x14200 bored softnet 44718 184938 0 0 3 0x14200 bored systqmp 87756 439899 0 0 3 0x14200 bored systq 89774 402769 0 0 3 0x40014200 bored softclock 50197 421999 0 0 3 0x40014200 idle0 1 7966 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb{0}> show all locks Process 47210 (syz-executor.1) thread 0xffff800021f942a0 (480872) exclusive rwlock netlock r = 0 (0xffffffff827a6120) #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 9505 6417K 6674K 78643K 11222 0 pcb 13 8K 8K 78643K 567 0 rtable 146 10K 11K 78643K 437 0 ifaddr 70 15K 15K 78643K 128 0 counters 43 33K 34K 78643K 61 0 ioctlops 0 0K 4K 78643K 1572 0 iov 0 0K 12K 78643K 48 0 mount 1 1K 1K 78643K 1 0 vnodes 1222 77K 77K 78643K 1430 0 UFS quota 1 32K 32K 78643K 1 0 UFS mount 5 36K 36K 78643K 5 0 shm 2 1K 5K 78643K 4 0 VM map 2 1K 1K 78643K 2 0 sem 12 0K 0K 78643K 159 0 dirhash 12 2K 2K 78643K 12 0 ACPI 1824 197K 290K 78643K 13058 0 file desc 5 13K 25K 78643K 708 0 sigio 0 0K 0K 78643K 5 0 proc 62 63K 95K 78643K 497 0 subproc 32 2K 2K 78643K 51 0 NFS srvsock 1 0K 0K 78643K 1 0 NFS daemon 1 16K 16K 78643K 1 0 ip_moptions 0 0K 0K 78643K 39 0 in_multi 44 2K 2K 78643K 80 0 ether_multi 1 0K 0K 78643K 5 0 ISOFS mount 1 32K 32K 78643K 1 0 MSDOSFS mount 1 16K 16K 78643K 1 0 ttys 67 307K 307K 78643K 67 0 exec 0 0K 1K 78643K 259 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 167 59K 61K 78643K 3092 0 UVM aobj 11 2K 2K 78643K 11 0 memdesc 1 4K 4K 78643K 1 0 crypto data 1 1K 1K 78643K 1 0 ip6_options 0 0K 1K 78643K 48 0 NDP 10 0K 0K 78643K 28 0 temp 124 3872K 3936K 78643K 4005 0 kqueue 3 4K 10K 78643K 14 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 5 1 0 1 1 0 8 0 plcache 128 20 0 0 1 0 1 1 0 8 0 rtpcb 88 37 0 35 1 0 1 1 0 8 0 rtentry 112 83 0 33 2 0 2 2 0 8 0 unpcb 120 808 0 796 1 0 1 1 0 8 0 syncache 272 11 0 11 3 2 1 1 0 8 1 tcpqe 32 312 0 312 2 1 1 1 0 8 1 tcpcb 592 166 0 159 4 2 2 2 0 8 1 inpcb 296 1443 0 1430 2 0 2 2 0 8 0 nd6 48 21 0 11 1 0 1 1 0 8 0 ppxss 1136 2 0 2 2 2 0 1 0 8 0 pfstscr 40 2 0 2 1 1 0 1 0 8 0 pffrag 232 6 0 6 2 2 0 1 0 482 0 pffrnode 88 6 0 6 2 2 0 1 0 8 0 pffrent 40 100 0 100 2 2 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 21 0 10 2 1 1 2 0 8 0 pftag 88 2 0 2 1 1 0 1 0 8 0 pfstitem 24 37 0 21 1 0 1 1 0 8 0 pfstkey 112 37 0 21 1 0 1 1 0 8 0 pfstate 328 35 0 19 3 0 3 3 0 8 0 pfrule 1360 38 0 22 4 2 2 2 0 8 0 art_heap8 4096 1 0 0 1 0 1 1 0 8 0 art_heap4 256 328 0 87 17 1 16 17 0 8 0 art_table 32 329 0 87 3 1 2 3 0 8 0 art_node 16 80 0 35 1 0 1 1 0 8 0 sysvmsgpl 40 7 0 1 1 0 1 1 0 8 0 semupl 112 2 0 2 1 1 0 1 0 8 0 semapl 112 157 0 147 1 0 1 1 0 8 0 shmpl 112 8 0 0 1 0 1 1 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino2pl 256 2218 0 815 88 0 88 88 0 8 0 ffsino 272 2218 0 815 94 0 94 94 0 8 0 nchpl 144 3373 0 1778 60 0 60 60 0 8 0 uvmvnodes 72 2418 0 0 44 0 44 44 0 8 0 vnodes 208 2418 0 0 128 0 128 128 0 8 0 namei 1024 8973 0 8973 1 0 1 1 0 8 1 percpumem 16 41 0 9 1 0 1 1 0 8 0 vcpupl 1984 3 0 0 1 0 1 1 0 8 0 vmpool 560 5 0 2 2 1 1 1 0 8 0 pfiaddrpl 120 23 0 6 1 0 1 1 0 8 0 scxspl 200 9666 0 9666 8 7 1 7 0 8 1 plimitpl 152 48 0 40 1 0 1 1 0 8 0 sigapl 424 943 0 891 6 0 6 6 0 8 0 futexpl 56 9725 0 9725 1 0 1 1 0 8 1 knotepl 112 88 0 68 1 0 1 1 0 8 0 kqueuepl 152 66 0 64 1 0 1 1 0 8 0 pipepl 304 169 0 158 2 0 2 2 0 8 0 fdescpl 496 905 0 889 3 0 3 3 0 8 0 filepl 152 5371 0 5267 5 0 5 5 0 8 0 lockfpl 104 102 0 101 1 0 1 1 0 8 0 lockfspl 48 35 0 34 1 0 1 1 0 8 0 sessionpl 120 19 0 8 1 0 1 1 0 8 0 pgrppl 48 25 0 14 1 0 1 1 0 8 0 ucredpl 96 398 0 388 1 0 1 1 0 8 0 zombiepl 144 891 0 891 1 0 1 1 0 8 1 processpl 1008 943 0 891 7 0 7 7 0 8 0 procpl 632 2240 0 2178 6 0 6 6 0 8 0 srpgc 72 2 0 2 1 1 0 1 0 8 0 sockpl 400 2350 0 2323 5 1 4 5 0 8 1 mcl64k 65536 6 0 0 1 0 1 1 0 8 0 mcl16k 16384 1 0 0 1 0 1 1 0 8 0 mcl12k 12288 7 0 0 1 0 1 1 0 8 0 mcl9k 9216 4 0 0 1 0 1 1 0 8 0 mcl8k 8192 6 0 0 1 0 1 1 0 8 0 mcl4k 4096 13 0 0 2 0 2 2 0 8 0 mcl2k 2048 191 0 0 23 0 23 23 0 8 0 mtagpl 96 26 0 0 1 0 1 1 0 8 0 mbufpl 256 341 0 0 21 0 21 21 0 8 0 bufpl 280 4312 0 127 299 0 299 299 0 8 0 anonpl 16 96493 0 78051 84 7 77 83 0 124 0 amapchunkpl 152 4802 0 4491 20 6 14 17 0 158 1 amappl16 192 3296 0 2440 46 3 43 44 0 8 0 amappl15 184 480 0 479 2 1 1 1 0 8 0 amappl14 176 3 0 2 1 0 1 1 0 8 0 amappl13 168 35 0 32 1 0 1 1 0 8 0 amappl12 160 209 0 201 1 0 1 1 0 8 0 amappl11 152 70 0 53 1 0 1 1 0 8 0 amappl10 144 500 0 494 1 0 1 1 0 8 0 amappl9 136 363 0 362 1 0 1 1 0 8 0 amappl8 128 379 0 336 2 0 2 2 0 8 0 amappl7 120 122 0 110 1 0 1 1 0 8 0 amappl6 112 35 0 28 1 0 1 1 0 8 0 amappl5 104 987 0 969 1 0 1 1 0 8 0 amappl4 96 509 0 480 1 0 1 1 0 8 0 amappl3 88 148 0 140 1 0 1 1 0 8 0 amappl2 80 6692 0 6622 2 0 2 2 0 8 0 amappl1 72 34541 0 34083 23 13 10 18 0 8 0 amappl 80 2533 0 2451 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 10 0 0 1 0 1 1 0 8 0 uaddrrnd 24 910 0 891 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 910 0 891 1 0 1 1 0 8 0 vmmpekpl 168 9065 0 9020 3 0 3 3 0 8 0 vmmpepl 168 121068 0 118978 152 43 109 125 0 357 18 vmsppl 368 909 0 891 2 0 2 2 0 8 0 pdppl 4096 1827 0 1785 7 1 6 6 0 8 0 pvpl 32 310317 0 288568 202 18 184 197 0 265 5 pmappl 232 909 0 891 3 1 2 2 0 8 0 extentpl 40 53 0 36 1 0 1 1 0 8 0 phpool 112 276 0 9 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(ffffffff8240acfd) at panic+0x164 sys/kern/subr_prf.c:218 pool_cache_get(ffffffff828ce6d0) at pool_cache_get+0x323 pool_cache_item_magic_check sys/kern/subr_pool.c:1781 [inline] pool_cache_get(ffffffff828ce6d0) at pool_cache_get+0x323 sys/kern/subr_pool.c:1884 pool_get(ffffffff828ce6d0,2) at pool_get+0x91 sys/kern/subr_pool.c:572 m_gethdr(2,2) at m_gethdr+0x4c sys/kern/uipc_mbuf.c:283 ip6_fragment(fffffd806ca14b00,28,11,500) at ip6_fragment+0xec sys/netinet6/ip6_output.c:810 ip6_output(fffffd806ca14b00,0,fffffd8077625ae0,0,0,fffffd8077625a70) at ip6_output+0x1ba2 sys/netinet6/ip6_output.c:736 udp6_output(fffffd8077625a70,fffffd8063efe600,0,0) at udp6_output+0x36a sys/netinet6/udp6_output.c:236 sosend(fffffd8077624978,0,ffff800021fab5e0,0,0,8a) at sosend+0x671 sys/kern/uipc_socket.c:555 sendit(ffff800021f942a0,6,ffff800021fab6c0,a,ffff800021fab7a0) at sendit+0x52b sys/kern/uipc_syscalls.c:657 sys_sendto(ffff800021f942a0,ffff800021fab758,ffff800021fab7a0) at sys_sendto+0x80 sys/kern/uipc_syscalls.c:522 syscall(ffff800021fab820) at syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:102 [inline] syscall(ffff800021fab820) at syscall+0x4a4 sys/arch/amd64/amd64/trap.c:570 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0xeaaf7cec810, count: -13 ddb{0}> machine ddbcpu 1