panic: pool_cache_item_magic_check: mbufpl cpu free list modified: item addr 0xfffffd806f26ff00+24 0x455a6d90092bd34d!=0xbaa590106456bc4d Stopped at db_enter+0x18: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND 174728 52217 0 0x2 0 0 syz-executor.0 *322572 64588 0 0x12 0 1 sshd 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(ffffffff82639e38) at pool_cache_get+0x323 pool_cache_item_magic_check sys/kern/subr_pool.c:1789 [inline] pool_cache_get(ffffffff82639e38) 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(fffffd807f02b300,0,54,2) at m_copym+0x174 m_get sys/kern/uipc_mbuf.c:250 [inline] m_copym(fffffd807f02b300,0,54,2) at m_copym+0x174 sys/kern/uipc_mbuf.c:667 tcp_output(ffff800000a7aee0) at tcp_output+0x151c sys/netinet/tcp_output.c:673 tcp_usrreq(fffffd806e97f608,9,fffffd807f02b300,0,0,ffff800020ac1b38) at tcp_usrreq+0xa45 sosend(fffffd806e97f608,0,ffff800020aeaee8,0,0,80) at sosend+0x645 sys/kern/uipc_socket.c:524 dofilewritev(ffff800020ac1b38,4,ffff800020aeaee8,0,ffff800020aeafd0) at dofilewritev+0x1b7 sys/kern/sys_generic.c:364 sys_write(ffff800020ac1b38,ffff800020aeaf80,ffff800020aeafd0) at sys_write+0x83 sys/kern/sys_generic.c:284 syscall(ffff800020aeb050) at syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:92 [inline] syscall(ffff800020aeb050) at syscall+0x4a4 sys/arch/amd64/amd64/trap.c:555 Xsyscall(0,4,9c58f1616b,4,4,9e5baf47c0) at Xsyscall+0x128 end of kernel end trace frame: 0x7f7ffffe9100, count: 3 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 0xfffffd806f26ff00+24 0x455a6d90092bd34d!=0xbaa590106456bc4d 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(ffffffff82639e38) at pool_cache_get+0x323 pool_cache_item_magic_check sys/kern/subr_pool.c:1789 [inline] pool_cache_get(ffffffff82639e38) 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(fffffd807f02b300,0,54,2) at m_copym+0x174 m_get sys/kern/uipc_mbuf.c:250 [inline] m_copym(fffffd807f02b300,0,54,2) at m_copym+0x174 sys/kern/uipc_mbuf.c:667 tcp_output(ffff800000a7aee0) at tcp_output+0x151c sys/netinet/tcp_output.c:673 tcp_usrreq(fffffd806e97f608,9,fffffd807f02b300,0,0,ffff800020ac1b38) at tcp_usrreq+0xa45 sosend(fffffd806e97f608,0,ffff800020aeaee8,0,0,80) at sosend+0x645 sys/kern/uipc_socket.c:524 dofilewritev(ffff800020ac1b38,4,ffff800020aeaee8,0,ffff800020aeafd0) at dofilewritev+0x1b7 sys/kern/sys_generic.c:364 sys_write(ffff800020ac1b38,ffff800020aeaf80,ffff800020aeafd0) at sys_write+0x83 sys/kern/sys_generic.c:284 syscall(ffff800020aeb050) at syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:92 [inline] syscall(ffff800020aeb050) at syscall+0x4a4 sys/arch/amd64/amd64/trap.c:555 Xsyscall(0,4,9c58f1616b,4,4,9e5baf47c0) at Xsyscall+0x128 end of kernel end trace frame: 0x7f7ffffe9100, count: -12 ddb{1}> show registers rdi 0 rsi 0x1 rbp 0xffff800020aea890 rbx 0xffff800020aea940 rdx 0x8b rcx 0x2 rax 0x1 r8 0xffffffff81bed2cf kprintf+0x16f r9 0x1 r10 0xcf490a3ea23378a1 r11 0x51c436c398ed3054 r12 0x3000000008 r13 0xffff800020aea8a0 r14 0x100 r15 0x1 rip 0xffffffff81463878 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff800020aea880 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{1}> show proc PROC (sshd) pid=322572 stat=onproc flags process=12 proc=0 pri=50, usrpri=50, nice=20 forw=0xffffffffffffffff, list=0xffff800020ac0500,0xffff800020ac0788 process=0xffff800020a8bc10 user=0xffff800020ae6000, vmspace=0xfffffd806e7dc178 estcpu=0, cpticks=2, pctcpu=0.0 user=0, sys=2, intr=0 ddb{1}> ps PID TID PPID UID S FLAGS WAIT COMMAND 52217 174728 8153 0 7 0x2 syz-executor.0 8153 2816 74365 0 3 0x82 kqread syz-execprog 8153 375466 74365 0 3 0x4000082 nanosleep syz-execprog 8153 65678 74365 0 3 0x4000082 thrsleep syz-execprog 8153 324452 74365 0 3 0x4000082 thrsleep syz-execprog 8153 503179 74365 0 3 0x4000082 thrsleep syz-execprog 8153 88071 74365 0 3 0x4000082 thrsleep syz-execprog 8153 490953 74365 0 3 0x4000082 thrsleep syz-execprog 8153 466848 74365 0 3 0x4000082 thrsleep syz-execprog 8153 441108 74365 0 3 0x4000082 nanosleep syz-execprog 74365 106372 64588 0 3 0x10008a pause ksh *64588 322572 1206 0 7 0x12 sshd 12146 328583 1 0 3 0x100083 ttyin getty 1206 497064 1 0 3 0x80 select sshd 92948 67887 1959 74 3 0x100092 bpf pflogd 1959 108559 1 0 3 0x80 netio pflogd 91705 506746 71739 73 3 0x100090 kqread syslogd 71739 5967 1 0 3 0x100082 netio syslogd 51818 55457 1 77 3 0x100090 poll dhclient 74960 105382 1 0 3 0x80 poll dhclient 1251 170139 0 0 3 0x14200 pgzero zerothread 44270 335859 0 0 3 0x14200 aiodoned aiodoned 57919 375229 0 0 3 0x14200 syncer update 9007 21872 0 0 3 0x14200 cleaner cleaner 74388 74370 0 0 3 0x14200 reaper reaper 23717 264856 0 0 3 0x14200 pgdaemon pagedaemon 34105 238403 0 0 3 0x14200 bored crynlk 50658 81700 0 0 3 0x14200 bored crypto 31980 321260 0 0 3 0x40014200 acpi0 acpi0 65617 515062 0 0 3 0x40014200 idle1 46353 509547 0 0 3 0x14200 bored softnet 46770 372987 0 0 3 0x14200 bored systqmp 73098 152368 0 0 3 0x14200 bored systq 62536 21575 0 0 3 0x40014200 bored softclock 8656 86229 0 0 3 0x40014200 idle0 24911 235678 0 0 3 0x14200 bored smr 1 440396 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb{1}> show all locks Process 52217 (syz-executor.0) thread 0xffff800020a5ec60 (174728) exclusive rrwlock inode r = 0 (0xfffffd806b1832b8) #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 vget+0x1c3 sys/kern/vfs_subr.c:672 #6 ufs_ihashget+0x141 sys/ufs/ufs/ufs_ihash.c:119 #7 ffs_vget+0x74 sys/ufs/ffs/ffs_vfsops.c:1323 #8 ufs_lookup+0x14b4 sys/ufs/ufs/ufs_lookup.c:487 #9 VOP_LOOKUP+0x5b sys/kern/vfs_vops.c:91 #10 vfs_lookup+0x7a6 sys/kern/vfs_lookup.c:568 #11 namei+0x63c sys/kern/vfs_lookup.c:249 #12 dounlinkat+0x99 sys/kern/vfs_syscalls.c:1785 #13 syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:92 [inline] #13 syscall+0x4a4 sys/arch/amd64/amd64/trap.c:555 #14 Xsyscall+0x128 exclusive rrwlock inode r = 0 (0xfffffd806b183808) #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 vfs_lookup+0xe6 sys/kern/vfs_lookup.c:419 #6 namei+0x63c sys/kern/vfs_lookup.c:249 #7 dounlinkat+0x99 sys/kern/vfs_syscalls.c:1785 #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 Process 64588 (sshd) thread 0xffff800020ac1b38 (322572) exclusive rwlock netlock r = 0 (0xffffffff8250dc58) #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 dofilewritev+0x1b7 sys/kern/sys_generic.c:364 #4 sys_write+0x83 sys/kern/sys_generic.c:284 #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 9457 6385K 6385K 78643K 10544 0 0 pcb 13 8K 8K 78643K 13 0 0 rtable 77 2K 2K 78643K 165 0 0 ifaddr 32 9K 9K 78643K 557 0 0 counters 39 33K 33K 78643K 39 0 0 ioctlops 0 0K 4K 78643K 1468 0 0 mount 1 1K 1K 78643K 1 0 0 vnodes 1181 74K 74K 78643K 1186 0 0 UFS quota 1 32K 32K 78643K 1 0 0 UFS mount 5 36K 36K 78643K 5 0 0 shm 2 1K 1K 78643K 2 0 0 VM map 2 1K 1K 78643K 2 0 0 sem 2 0K 0K 78643K 2 0 0 dirhash 12 2K 2K 78643K 12 0 0 ACPI 1808 196K 290K 78643K 12765 0 0 file desc 2 4K 12K 78643K 542 0 0 proc 59 63K 83K 78643K 384 0 0 NFS srvsock 1 0K 0K 78643K 1 0 0 NFS daemon 1 16K 16K 78643K 1 0 0 in_multi 22 1K 1K 78643K 22 0 0 ether_multi 1 0K 0K 78643K 1 0 0 ISOFS mount 1 32K 32K 78643K 1 0 0 MSDOSFS mount 1 16K 16K 78643K 1 0 0 ttys 18 79K 79K 78643K 18 0 0 exec 0 0K 1K 78643K 199 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 74 12K 12K 78643K 1484 0 0 UVM aobj 2 2K 2K 78643K 2 0 0 memdesc 1 4K 4K 78643K 1 0 0 crypto data 1 1K 1K 78643K 1 0 0 NDP 5 0K 0K 78643K 7 0 0 temp 48 3542K 3606K 78643K 4386 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 4 0 1 1 0 1 1 0 8 0 plcache 128 20 0 0 1 0 1 1 0 8 0 rtpcb 80 17 0 15 1 0 1 1 0 8 0 rtentry 112 34 0 4 1 0 1 1 0 8 0 unpcb 120 29 0 19 1 0 1 1 0 8 0 syncache 264 5 0 5 1 1 0 1 0 8 0 tcpqe 32 24 0 24 1 1 0 1 0 8 0 tcpcb 544 8 0 5 1 0 1 1 0 8 0 inpcb 280 558 0 552 1 0 1 1 0 8 0 nd6 48 2 0 0 1 0 1 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 10 0 2 1 0 1 1 0 8 0 pfstkey 112 10 0 2 1 0 1 1 0 8 0 pfstate 328 10 0 2 1 0 1 1 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 256 167 0 2 11 0 11 11 0 8 0 art_table 32 168 0 2 2 0 2 2 0 8 0 art_node 16 33 0 6 1 0 1 1 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino1pl 128 1946 0 544 46 0 46 46 0 8 0 ffsino 272 1946 0 544 94 0 94 94 0 8 0 nchpl 144 2709 0 1099 60 0 60 60 0 8 0 uvmvnodes 72 1956 0 0 36 0 36 36 0 8 0 vnodes 208 1956 0 0 103 0 103 103 0 8 0 namei 1024 6240 0 6240 2 1 1 1 0 8 1 percpumem 16 30 0 0 1 0 1 1 0 8 0 scxspl 192 7387 0 7387 9 8 1 7 0 8 1 plimitpl 152 15 0 8 1 0 1 1 0 8 0 sigapl 432 750 0 737 2 0 2 2 0 8 0 knotepl 112 39 0 28 1 0 1 1 0 8 0 kqueuepl 104 2 0 0 1 0 1 1 0 8 0 pipepl 112 154 0 141 2 1 1 1 0 8 0 fdescpl 488 751 0 737 3 0 3 3 0 8 0 filepl 152 2170 0 2112 3 0 3 3 0 8 0 lockfpl 104 5 0 4 1 0 1 1 0 8 0 lockfspl 48 3 0 2 1 0 1 1 0 8 0 sessionpl 112 19 0 9 1 0 1 1 0 8 0 pgrppl 48 19 0 9 1 0 1 1 0 8 0 ucredpl 96 52 0 43 1 0 1 1 0 8 0 zombiepl 144 737 0 737 2 1 1 1 0 8 1 processpl 896 766 0 737 4 0 4 4 0 8 0 procpl 632 774 0 737 4 0 4 4 0 8 0 sockpl 384 604 0 586 2 0 2 2 0 8 0 mcl4k 4096 3 0 0 1 0 1 1 0 8 0 mcl2k 2048 79 0 0 10 0 10 10 0 8 0 mtagpl 80 1 0 0 1 0 1 1 0 8 0 mbufpl 256 109 0 0 6 0 6 6 0 8 0 mbufpl: pool(0xffffffff82639e38:mbufpl): free list modified: page 0xfffffd806d7d6000; item ordinal 0; addr 0xfffffd806d7d6300 (p 0xfffffd806d864000); offset 0x0=0x0 bufpl 256 6411 0 1315 319 0 319 319 0 8 0 anonpl 16 36221 0 34014 15 6 9 13 0 124 0 amapchunkpl 152 1333 0 1268 5 2 3 5 0 158 0 amappl16 192 2319 0 2244 4 0 4 4 0 8 0 amappl15 184 1 0 1 1 1 0 1 0 8 0 amappl14 176 30 0 25 2 1 1 1 0 8 0 amappl13 168 525 0 524 1 0 1 1 0 8 0 amappl12 160 4 0 3 2 1 1 1 0 8 0 amappl11 152 49 0 34 1 0 1 1 0 8 0 amappl10 144 11 0 9 1 0 1 1 0 8 0 amappl9 136 454 0 448 1 0 1 1 0 8 0 amappl8 128 132 0 120 1 0 1 1 0 8 0 amappl7 120 34 0 31 1 0 1 1 0 8 0 amappl6 112 81 0 72 1 0 1 1 0 8 0 amappl5 104 138 0 125 1 0 1 1 0 8 0 amappl4 96 1028 0 1000 1 0 1 1 0 8 0 amappl3 88 116 0 110 1 0 1 1 0 8 0 amappl2 80 2531 0 2468 3 1 2 3 0 8 0 amappl1 72 19258 0 18842 26 13 13 20 0 8 3 amappl 80 1001 0 973 1 0 1 1 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 1 0 0 1 0 1 1 0 8 0 uaddrrnd 24 751 0 737 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 751 0 737 1 0 1 1 0 8 0 vmmpekpl 168 7478 0 7457 2 0 2 2 0 8 0 vmmpepl 168 56359 0 55387 96 21 75 80 0 357 32 vmsppl 368 750 0 737 2 0 2 2 0 8 0 pdppl 4096 1509 0 1474 6 1 5 6 0 8 0 pvpl 32 166210 0 161621 119 9 110 115 0 265 72 pmappl 232 750 0 737 1 0 1 1 0 8 0 extentpl 40 41 0 26 1 0 1 1 0 8 0 phpool 112 460 0 5 13 0 13 13 0 8 0