panic: pool_cache_item_magic_check: mbufpl cpu free list modified: item addr 0xfffffd806d7b0f00+16 0x0!=0x262982bb46937c2b Stopped at db_enter+0x18: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND 100220 4065 0 0 0 1 syz-executor.1 *248851 4065 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_copym(fffffd8064481b00,7878,4d0,2) at m_copym+0x174 m_get sys/kern/uipc_mbuf.c:250 [inline] m_copym(fffffd8064481b00,7878,4d0,2) at m_copym+0x174 sys/kern/uipc_mbuf.c:667 ip6_fragment(fffffd8064481b00,28,11,500) at ip6_fragment+0x33e sys/netinet6/ip6_output.c:829 ip6_output(fffffd8064481b00,0,fffffd806719e078,0,0,fffffd806719e008) at ip6_output+0x1ba2 sys/netinet6/ip6_output.c:736 udp6_output(fffffd806719e008,fffffd8064483400,0,0) at udp6_output+0x36a sys/netinet6/udp6_output.c:236 sosend(fffffd806ca39010,0,ffff800021ee5b80,0,0,8a) at sosend+0x671 sys/kern/uipc_socket.c:555 sendit(ffff800020ea0508,8,ffff800021ee5c60,a,ffff800021ee5d40) at sendit+0x52b sys/kern/uipc_syscalls.c:657 sys_sendto(ffff800020ea0508,ffff800021ee5cf8,ffff800021ee5d40) at sys_sendto+0x80 sys/kern/uipc_syscalls.c:522 syscall(ffff800021ee5dc0) at syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:102 [inline] syscall(ffff800021ee5dc0) at syscall+0x4a4 sys/arch/amd64/amd64/trap.c:570 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x72a5d93a6f0, 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 0xfffffd806d7b0f00+16 0x0!=0x262982bb46937c2b 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_copym(fffffd8064481b00,7878,4d0,2) at m_copym+0x174 m_get sys/kern/uipc_mbuf.c:250 [inline] m_copym(fffffd8064481b00,7878,4d0,2) at m_copym+0x174 sys/kern/uipc_mbuf.c:667 ip6_fragment(fffffd8064481b00,28,11,500) at ip6_fragment+0x33e sys/netinet6/ip6_output.c:829 ip6_output(fffffd8064481b00,0,fffffd806719e078,0,0,fffffd806719e008) at ip6_output+0x1ba2 sys/netinet6/ip6_output.c:736 udp6_output(fffffd806719e008,fffffd8064483400,0,0) at udp6_output+0x36a sys/netinet6/udp6_output.c:236 sosend(fffffd806ca39010,0,ffff800021ee5b80,0,0,8a) at sosend+0x671 sys/kern/uipc_socket.c:555 sendit(ffff800020ea0508,8,ffff800021ee5c60,a,ffff800021ee5d40) at sendit+0x52b sys/kern/uipc_syscalls.c:657 sys_sendto(ffff800020ea0508,ffff800021ee5cf8,ffff800021ee5d40) at sys_sendto+0x80 sys/kern/uipc_syscalls.c:522 syscall(ffff800021ee5dc0) at syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:102 [inline] syscall(ffff800021ee5dc0) at syscall+0x4a4 sys/arch/amd64/amd64/trap.c:570 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x72a5d93a6f0, count: -13 ddb{0}> show registers rdi 0 rsi 0x1 rbp 0xffff800021ee5470 rbx 0xffff800021ee5520 rdx 0x8b rcx 0x2 rax 0x1 r8 0xffff800021ee5430 r9 0xffffffff8108ddff kprintf+0x16f r10 0x1 r11 0x9b789d1bca16f2b8 r12 0x3000000008 r13 0xffff800021ee5480 r14 0x100 r15 0x1 rip 0xffffffff822b91e8 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff800021ee5460 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{0}> show proc PROC (syz-executor.1) pid=248851 stat=onproc flags process=0 proc=4000000 pri=32, usrpri=86, nice=20 forw=0xffffffffffffffff, list=0xffff800020ea1650,0xffffffff828cde18 process=0xffff800020ea27e8 user=0xffff800021ee0000, vmspace=0xfffffd807effe730 estcpu=36, cpticks=2, pctcpu=0.0 user=0, sys=1, intr=0 ddb{0}> ps PID TID PPID UID S FLAGS WAIT COMMAND 4065 100220 55843 0 7 0 syz-executor.1 * 4065 248851 55843 0 7 0x4000000 syz-executor.1 57133 484705 0 0 3 0x14200 bored sosplice 55843 27289 6756 0 3 0x82 nanosleep syz-executor.1 99505 449667 6756 0 2 0x2 syz-executor.0 6756 438325 66050 0 3 0x82 thrsleep syz-fuzzer 6756 81344 66050 0 3 0x4000082 thrsleep syz-fuzzer 6756 462283 66050 0 3 0x4000082 thrsleep syz-fuzzer 6756 314323 66050 0 3 0x4000082 thrsleep syz-fuzzer 6756 257371 66050 0 3 0x4000082 thrsleep syz-fuzzer 6756 444300 66050 0 3 0x4000082 thrsleep syz-fuzzer 6756 383282 66050 0 3 0x4000082 thrsleep syz-fuzzer 6756 161634 66050 0 3 0x4000082 kqread syz-fuzzer 66050 251491 62211 0 3 0x10008a pause ksh 62211 104699 99954 0 3 0x92 select sshd 94129 101875 1 0 3 0x100083 ttyin getty 99954 206214 1 0 3 0x80 select sshd 70964 281943 25040 74 3 0x100092 bpf pflogd 25040 32365 1 0 3 0x80 netio pflogd 95266 373460 7246 73 3 0x100090 kqread syslogd 7246 256053 1 0 3 0x100082 netio syslogd 25465 267825 1 77 3 0x100090 poll dhclient 22632 338292 1 0 3 0x80 poll dhclient 52168 439379 0 0 3 0x14200 bored smr 50357 257270 0 0 2 0x14200 zerothread 65537 478464 0 0 3 0x14200 aiodoned aiodoned 67441 287955 0 0 3 0x14200 syncer update 75081 123837 0 0 3 0x14200 cleaner cleaner 45535 127996 0 0 3 0x14200 reaper reaper 47089 304244 0 0 3 0x14200 pgdaemon pagedaemon 81908 97718 0 0 3 0x14200 bored crynlk 779 20786 0 0 3 0x14200 bored crypto 73515 204070 0 0 3 0x40014200 acpi0 acpi0 42817 21743 0 0 3 0x40014200 idle1 24018 503582 0 0 3 0x14200 bored softnet 77220 137532 0 0 3 0x14200 bored systqmp 94276 330338 0 0 3 0x14200 bored systq 36447 312084 0 0 3 0x40014200 bored softclock 23005 331692 0 0 3 0x40014200 idle0 1 25932 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb{0}> show all locks Process 4065 (syz-executor.1) thread 0xffff800020ea0508 (248851) 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 Process 99505 (syz-executor.0) thread 0xffff800020dd6008 (449667) exclusive rrwlock inode r = 0 (0xfffffd806c9f6918) #0 witness_lock+0x4c7 stacktrace_save sys/sys/stacktrace.h:36 [inline] #0 witness_lock+0x4c7 sys/kern/subr_witness.c:1164 #1 rw_enter+0x453 sys/kern/kern_rwlock.c:311 #2 rrw_enter+0x88 sys/kern/kern_rwlock.c:462 #3 ufs_ihashins+0x45 sys/ufs/ufs/ufs_ihash.c:140 #4 ffs_vget+0x13e sys/ufs/ffs/ffs_vfsops.c:1358 #5 ffs_inode_alloc+0x1e2 sys/ufs/ffs/ffs_alloc.c:394 #6 ufs_mkdir+0xf4 sys/ufs/ufs/ufs_vnops.c:1162 #7 VOP_MKDIR+0xc6 sys/kern/vfs_vops.c:450 #8 domkdirat+0x121 sys/kern/vfs_syscalls.c:3051 #9 syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:102 [inline] #9 syscall+0x4a4 sys/arch/amd64/amd64/trap.c:570 #10 Xsyscall+0x128 exclusive rrwlock inode r = 0 (0xfffffd806c9f65e8) #0 witness_lock+0x4c7 stacktrace_save sys/sys/stacktrace.h:36 [inline] #0 witness_lock+0x4c7 sys/kern/subr_witness.c:1164 #1 rw_enter+0x453 sys/kern/kern_rwlock.c:311 #2 rrw_enter+0x88 sys/kern/kern_rwlock.c:462 #3 VOP_LOCK+0x4b sys/kern/vfs_vops.c:603 #4 vn_lock+0x81 sys/kern/vfs_vnops.c:575 #5 vfs_lookup+0xe6 sys/kern/vfs_lookup.c:419 #6 namei+0x63c sys/kern/vfs_lookup.c:249 #7 domkdirat+0x75 sys/kern/vfs_syscalls.c:3036 #8 syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:102 [inline] #8 syscall+0x4a4 sys/arch/amd64/amd64/trap.c:570 #9 Xsyscall+0x128 ddb{0}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim devbuf 9490 6407K 6673K 78643K 10807 0 pcb 13 8K 8K 78643K 37 0 rtable 90 2K 7K 78643K 276 0 ifaddr 62 14K 14K 78643K 88 0 counters 43 33K 33K 78643K 43 0 ioctlops 0 0K 4K 78643K 1504 0 iov 0 0K 12K 78643K 15 0 mount 1 1K 1K 78643K 1 0 vnodes 1219 77K 77K 78643K 1292 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 1K 78643K 47 0 dirhash 12 2K 2K 78643K 12 0 ACPI 1824 197K 290K 78643K 13058 0 file desc 5 13K 25K 78643K 216 0 sigio 0 0K 0K 78643K 5 0 proc 61 63K 95K 78643K 451 0 subproc 32 2K 2K 78643K 34 0 NFS srvsock 1 0K 0K 78643K 1 0 NFS daemon 1 16K 16K 78643K 1 0 ip_moptions 0 0K 0K 78643K 16 0 in_multi 59 3K 3K 78643K 70 0 ether_multi 1 0K 0K 78643K 5 0 mrt 0 0K 0K 78643K 7 0 ISOFS mount 1 32K 32K 78643K 1 0 MSDOSFS mount 1 16K 16K 78643K 1 0 ttys 49 228K 228K 78643K 49 0 exec 0 0K 1K 78643K 223 0 pfkey data 0 0K 0K 78643K 2 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 165 43K 43K 78643K 1732 0 UVM aobj 9 2K 2K 78643K 9 0 memdesc 1 4K 4K 78643K 1 0 crypto data 1 1K 1K 78643K 1 0 ip6_options 0 0K 1K 78643K 23 0 NDP 8 0K 0K 78643K 12 0 temp 116 3870K 3934K 78643K 2964 0 kqueue 3 4K 18K 78643K 18 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 7 0 0 1 0 1 1 0 8 0 plcache 128 20 0 0 1 0 1 1 0 8 0 rtpcb 88 27 0 25 1 0 1 1 0 8 0 rtentry 112 52 0 16 2 0 2 2 0 8 0 unpcb 120 198 0 186 1 0 1 1 0 8 0 syncache 272 4 0 4 1 1 0 1 0 8 0 tcpqe 32 719 0 719 1 1 0 1 0 8 0 tcpcb 592 417 0 396 5 0 5 5 0 8 3 inpcb 296 591 0 581 2 0 2 2 0 8 0 rttmr 72 3 0 3 1 0 1 1 0 8 1 nd6 48 6 0 0 1 0 1 1 0 8 0 pkpcb 40 4 0 4 1 1 0 1 0 8 0 pffrag 232 3 0 3 2 1 1 1 0 482 1 pffrnode 88 3 0 3 2 1 1 1 0 8 1 pffrent 40 135 0 135 2 1 1 1 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 pfrktable 1344 19 0 19 1 1 0 1 0 8 0 pfstitem 24 29 0 3 1 0 1 1 0 8 0 pfstkey 112 29 0 3 1 0 1 1 0 8 0 pfstate 328 29 0 3 3 0 3 3 0 8 0 pfrule 1360 26 0 22 2 1 1 2 0 8 0 art_heap8 4096 1 0 0 1 0 1 1 0 8 0 art_heap4 256 257 0 72 13 1 12 13 0 8 0 art_table 32 258 0 72 2 0 2 2 0 8 0 art_node 16 51 0 20 1 0 1 1 0 8 0 sysvmsgpl 40 6 0 2 1 0 1 1 0 8 0 semupl 112 1 0 1 1 1 0 1 0 8 0 semapl 112 41 0 31 1 0 1 1 0 8 0 shmpl 112 6 0 0 1 0 1 1 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino2pl 256 1671 0 268 88 0 88 88 0 8 0 ffsino 272 1671 0 268 94 0 94 94 0 8 0 nchpl 144 2144 0 537 60 0 60 60 0 8 0 uvmvnodes 72 1767 0 0 33 0 33 33 0 8 0 vnodes 208 1767 0 0 93 0 93 93 0 8 0 namei 1024 6197 0 6196 1 0 1 1 0 8 0 percpumem 16 32 0 0 1 0 1 1 0 8 0 vcpupl 1984 2 0 0 1 0 1 1 0 8 0 vmpool 560 2 0 0 1 0 1 1 0 8 0 pfiaddrpl 120 5 0 5 1 1 0 1 0 8 0 scxspl 200 6271 0 6271 8 7 1 7 0 8 1 plimitpl 152 25 0 17 1 0 1 1 0 8 0 sigapl 424 432 0 400 4 0 4 4 0 8 0 futexpl 56 3315 0 3315 1 0 1 1 0 8 1 knotepl 112 132 0 112 2 0 2 2 0 8 1 kqueuepl 152 50 0 45 1 0 1 1 0 8 0 pipepl 304 103 0 92 2 0 2 2 0 8 1 fdescpl 496 416 0 400 3 0 3 3 0 8 0 filepl 152 2892 0 2785 5 0 5 5 0 8 0 lockfpl 104 59 0 58 1 0 1 1 0 8 0 lockfspl 48 22 0 21 1 0 1 1 0 8 0 sessionpl 120 18 0 7 1 0 1 1 0 8 0 pgrppl 48 24 0 13 1 0 1 1 0 8 0 ucredpl 96 187 0 178 1 0 1 1 0 8 0 zombiepl 144 400 0 400 1 0 1 1 0 8 1 processpl 1008 432 0 400 5 0 5 5 0 8 0 procpl 632 918 0 878 5 0 5 5 0 8 1 sosppl 144 5 0 5 2 1 1 1 0 8 1 sockpl 400 824 0 800 4 0 4 4 0 8 1 mcl64k 65536 5 0 0 1 0 1 1 0 8 0 mcl12k 12288 7 0 0 1 0 1 1 0 8 0 mcl9k 9216 1 0 0 1 0 1 1 0 8 0 mcl8k 8192 3 0 0 1 0 1 1 0 8 0 mcl4k 4096 4 0 0 1 0 1 1 0 8 0 mcl2k2 2112 1 0 0 1 0 1 1 0 8 0 mcl2k 2048 202 0 0 25 0 25 25 0 8 0 mtagpl 96 14 0 0 1 0 1 1 0 8 0 mbufpl 256 399 0 0 24 0 24 24 0 8 0 bufpl 280 3582 0 127 247 0 247 247 0 8 0 anonpl 16 58048 0 39410 82 5 77 81 0 124 2 amapchunkpl 152 2429 0 2162 14 2 12 13 0 158 1 amappl16 192 1887 0 989 50 4 46 50 0 8 1 amappl15 184 92 0 90 1 0 1 1 0 8 0 amappl14 176 95 0 91 1 0 1 1 0 8 0 amappl13 168 28 0 25 1 0 1 1 0 8 0 amappl12 160 23 0 18 1 0 1 1 0 8 0 amappl11 152 145 0 128 1 0 1 1 0 8 0 amappl10 144 15 0 11 1 0 1 1 0 8 0 amappl9 136 367 0 366 1 0 1 1 0 8 0 amappl8 128 363 0 318 2 0 2 2 0 8 0 amappl7 120 115 0 102 1 0 1 1 0 8 0 amappl6 112 119 0 113 1 0 1 1 0 8 0 amappl5 104 218 0 202 1 0 1 1 0 8 0 amappl4 96 578 0 549 1 0 1 1 0 8 0 amappl3 88 136 0 127 1 0 1 1 0 8 0 amappl2 80 2475 0 2406 2 0 2 2 0 8 0 amappl1 72 21277 0 20831 23 13 10 18 0 8 0 amappl 80 1202 0 1128 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 8 0 0 1 0 1 1 0 8 0 uaddrrnd 24 418 0 400 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 418 0 400 1 0 1 1 0 8 0 vmmpekpl 168 7374 0 7335 2 0 2 2 0 8 0 vmmpepl 168 60411 0 58303 118 16 102 112 0 357 8 vmsppl 368 417 0 400 2 0 2 2 0 8 0 pdppl 4096 843 0 802 7 1 6 6 0 8 0 pvpl 32 188686 0 166841 193 4 189 193 0 265 12 pmappl 232 417 0 400 3 1 2 2 0 8 0 extentpl 40 53 0 36 1 0 1 1 0 8 0 phpool 112 270 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_copym(fffffd8064481b00,7878,4d0,2) at m_copym+0x174 m_get sys/kern/uipc_mbuf.c:250 [inline] m_copym(fffffd8064481b00,7878,4d0,2) at m_copym+0x174 sys/kern/uipc_mbuf.c:667 ip6_fragment(fffffd8064481b00,28,11,500) at ip6_fragment+0x33e sys/netinet6/ip6_output.c:829 ip6_output(fffffd8064481b00,0,fffffd806719e078,0,0,fffffd806719e008) at ip6_output+0x1ba2 sys/netinet6/ip6_output.c:736 udp6_output(fffffd806719e008,fffffd8064483400,0,0) at udp6_output+0x36a sys/netinet6/udp6_output.c:236 sosend(fffffd806ca39010,0,ffff800021ee5b80,0,0,8a) at sosend+0x671 sys/kern/uipc_socket.c:555 sendit(ffff800020ea0508,8,ffff800021ee5c60,a,ffff800021ee5d40) at sendit+0x52b sys/kern/uipc_syscalls.c:657 sys_sendto(ffff800020ea0508,ffff800021ee5cf8,ffff800021ee5d40) at sys_sendto+0x80 sys/kern/uipc_syscalls.c:522 syscall(ffff800021ee5dc0) at syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:102 [inline] syscall(ffff800021ee5dc0) at syscall+0x4a4 sys/arch/amd64/amd64/trap.c:570 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x72a5d93a6f0, 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: 0x7f7fffff7700, 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: 0x7f7fffff7700, count: -3