panic: pool_cache_item_magic_check: mbufpl cpu free list modified: item addr 0xfffffd806f27b900+16 0x6c6bd6fe7e000000!=0x6c6bd6fe7e00c5e8 Stopped at db_enter+0x18: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND 318583 71149 0 0 0 0 syz-executor.0 * 14041 71149 0 0 0x4000000 1K syz-executor.0 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(ffffffff82658ba8) at pool_cache_get+0x323 pool_cache_item_magic_check sys/kern/subr_pool.c:1789 [inline] pool_cache_get(ffffffff82658ba8) 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(2,1) at m_gethdr+0x4c sys/kern/uipc_mbuf.c:283 tun_dev_write(ffff800000ae6000,ffff800022555678,d9) at tun_dev_write+0x96 spec_write(ffff8000225554c0) at spec_write+0xd4 sys/kern/spec_vnops.c:310 VOP_WRITE(fffffd806ebe90d8,ffff800022555678,11,fffffd807f7c6900) at VOP_WRITE+0xc6 sys/kern/vfs_vops.c:269 vn_write(fffffd806d895c00,ffff800022555678,0) at vn_write+0x14f sys/kern/vfs_vnops.c:405 dofilewritev(ffff800020abec70,f0,ffff800022555678,0,ffff800022555760) at dofilewritev+0x1b7 sys/kern/sys_generic.c:364 sys_write(ffff800020abec70,ffff800022555710,ffff800022555760) at sys_write+0x83 sys/kern/sys_generic.c:284 syscall(ffff8000225557e0) at syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:92 [inline] syscall(ffff8000225557e0) at syscall+0x4a4 sys/arch/amd64/amd64/trap.c:555 Xsyscall(6,4,0,4,2,4cce3d5ce00) at Xsyscall+0x128 end of kernel end trace frame: 0x4cbf8982440, 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{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 0xfffffd806f27b900+16 0x6c6bd6fe7e000000!=0x6c6bd6fe7e00c5e8 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(ffffffff82658ba8) at pool_cache_get+0x323 pool_cache_item_magic_check sys/kern/subr_pool.c:1789 [inline] pool_cache_get(ffffffff82658ba8) 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(2,1) at m_gethdr+0x4c sys/kern/uipc_mbuf.c:283 tun_dev_write(ffff800000ae6000,ffff800022555678,d9) at tun_dev_write+0x96 spec_write(ffff8000225554c0) at spec_write+0xd4 sys/kern/spec_vnops.c:310 VOP_WRITE(fffffd806ebe90d8,ffff800022555678,11,fffffd807f7c6900) at VOP_WRITE+0xc6 sys/kern/vfs_vops.c:269 vn_write(fffffd806d895c00,ffff800022555678,0) at vn_write+0x14f sys/kern/vfs_vnops.c:405 dofilewritev(ffff800020abec70,f0,ffff800022555678,0,ffff800022555760) at dofilewritev+0x1b7 sys/kern/sys_generic.c:364 sys_write(ffff800020abec70,ffff800022555710,ffff800022555760) at sys_write+0x83 sys/kern/sys_generic.c:284 syscall(ffff8000225557e0) at syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:92 [inline] syscall(ffff8000225557e0) at syscall+0x4a4 sys/arch/amd64/amd64/trap.c:555 Xsyscall(6,4,0,4,2,4cce3d5ce00) at Xsyscall+0x128 end of kernel end trace frame: 0x4cbf8982440, count: -13 ddb{1}> show registers rdi 0xffffffff81c5afd7 db_enter+0x17 rsi 0x369a __ALIGN_SIZE+0x269a rbp 0xffff800022555160 rbx 0xffff800022555210 rdx 0x369b __ALIGN_SIZE+0x269b rcx 0xffff800022966000 rax 0xffff800022966000 r8 0xffffffff81ebdc8f kprintf+0x16f r9 0x1 r10 0x25 r11 0x878cace07f75d87f r12 0x3000000008 r13 0xffff800022555170 r14 0x100 r15 0x1 rip 0xffffffff81c5afd8 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff800022555150 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{1}> show proc PROC (syz-executor.0) pid=14041 stat=onproc flags process=0 proc=4000000 pri=50, usrpri=50, nice=20 forw=0xffffffffffffffff, list=0xffff800020abf3d8,0xffff800020abe790 process=0xffff800020addc00 user=0xffff800022550000, vmspace=0xfffffd807f00ccf0 estcpu=8, cpticks=1, pctcpu=0.0 user=0, sys=1, intr=0 ddb{1}> ps PID TID PPID UID S FLAGS WAIT COMMAND 237 513053 53730 0 2 0 syz-executor.1 237 474387 53730 0 2 0x4000000 syz-executor.1 71149 318583 4314 0 7 0 syz-executor.0 71149 510027 4314 0 2 0x4000000 syz-executor.0 *71149 14041 4314 0 7 0x4000000 syz-executor.0 4314 191232 97034 0 3 0x82 nanosleep syz-executor.0 53730 513466 97034 0 3 0x82 nanosleep syz-executor.1 92541 276303 0 0 3 0x14200 bored sosplice 97034 53913 22643 0 3 0x82 thrsleep syz-fuzzer 97034 165322 22643 0 3 0x4000082 thrsleep syz-fuzzer 97034 363371 22643 0 3 0x4000082 thrsleep syz-fuzzer 97034 400990 22643 0 3 0x4000082 thrsleep syz-fuzzer 97034 461745 22643 0 3 0x4000082 thrsleep syz-fuzzer 97034 19867 22643 0 3 0x4000082 thrsleep syz-fuzzer 97034 215569 22643 0 3 0x4000082 thrsleep syz-fuzzer 97034 406602 22643 0 3 0x4000082 thrsleep syz-fuzzer 97034 433110 22643 0 3 0x4000082 kqread syz-fuzzer 97034 325827 22643 0 3 0x4000082 thrsleep syz-fuzzer 22643 297508 60998 0 3 0x10008a pause ksh 60998 499690 60497 0 3 0x92 select sshd 79412 461194 1 0 3 0x100083 ttyin getty 60497 319531 1 0 3 0x80 select sshd 81467 328044 71239 74 3 0x100092 bpf pflogd 71239 17731 1 0 3 0x80 netio pflogd 10582 57889 11918 73 3 0x100090 kqread syslogd 11918 83989 1 0 3 0x100082 netio syslogd 54078 51560 0 0 2 0x14200 zerothread 86040 453506 0 0 3 0x14200 aiodoned aiodoned 86825 240277 0 0 3 0x14200 syncer update 67133 286012 0 0 3 0x14200 cleaner cleaner 16581 29656 0 0 3 0x14200 reaper reaper 60797 369523 0 0 3 0x14200 pgdaemon pagedaemon 35584 295880 0 0 3 0x14200 bored crynlk 27777 330393 0 0 3 0x14200 bored crypto 73075 103633 0 0 3 0x40014200 acpi0 acpi0 9084 520434 0 0 3 0x40014200 idle1 79916 200713 0 0 3 0x14200 bored softnet 18319 137392 0 0 3 0x14200 bored systqmp 60884 9832 0 0 3 0x14200 bored systq 17099 154527 0 0 3 0x40014200 bored softclock 5356 275553 0 0 3 0x40014200 idle0 64902 313437 0 0 3 0x14200 bored smr 1 382424 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb{1}> show all locks Process 71149 (syz-executor.0) thread 0xffff800020abec70 (14041) exclusive kernel_lock &kernel_lock r = 0 (0xffffffff82623840) #0 witness_lock+0x52e sys/kern/subr_witness.c:1163 #1 vn_write+0x42 sys/kern/vfs_vnops.c:390 #2 dofilewritev+0x1b7 sys/kern/sys_generic.c:364 #3 sys_write+0x83 sys/kern/sys_generic.c:284 #4 syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:92 [inline] #4 syscall+0x4a4 sys/arch/amd64/amd64/trap.c:555 #5 Xsyscall+0x128 ddb{1}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim Kern Lim devbuf 9558 6451K 9035K 78643K 42616 0 0 pcb 13 10K 12K 78643K 1102 0 0 rtable 116 4K 5K 78643K 2231 0 0 ifaddr 72 26K 34K 78643K 2212 0 0 counters 39 33K 33K 78643K 39 0 0 ioctlops 0 0K 4K 78643K 1627 0 0 iov 0 0K 24K 78643K 1260 0 0 mount 1 1K 1K 78643K 1 0 0 vnodes 1245 78K 78K 78643K 9555 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 168 0 0 VM map 2 1K 1K 78643K 4 0 0 sem 12 0K 1K 78643K 1511 0 0 dirhash 12 2K 2K 78643K 12 0 0 ACPI 1808 196K 290K 78643K 12765 0 0 file desc 6 17K 25K 78643K 7660 0 0 sigio 0 0K 0K 78643K 31 0 0 proc 57 51K 95K 78643K 1561 0 0 subproc 32 2K 2K 78643K 412 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 10082 0 0 in_multi 33 2K 2K 78643K 1104 0 0 ether_multi 1 0K 0K 78643K 21 0 0 mrt 1 0K 0K 78643K 12 0 0 ISOFS mount 1 32K 32K 78643K 1 0 0 MSDOSFS mount 1 16K 16K 78643K 1 0 0 ttys 84 371K 371K 78643K 84 0 0 exec 0 0K 1K 78643K 1631 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 116 22K 31K 78643K 24230 0 0 UVM aobj 130 4K 4K 78643K 130 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 499 0 0 NDP 18 0K 0K 78643K 599 0 0 temp 200 3556K 4196K 78643K 55678 0 0 kqueue 0 0K 0K 78643K 14 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 64 222 0 217 1 0 1 1 0 8 0 plcache 128 20 0 0 1 0 1 1 0 8 0 rtpcb 80 635 0 635 3 2 1 1 0 8 1 rtentry 112 623 0 579 2 0 2 2 0 8 0 unpcb 120 2026 0 2008 5 4 1 2 0 8 0 syncache 264 9 0 9 4 4 0 1 0 8 0 tcpqe 32 5890 0 5890 3 3 0 1 0 8 0 tcpcb 544 9572 0 9568 18 17 1 3 0 8 0 inpcb 280 17449 0 17445 24 23 1 13 0 8 0 rttmr 72 3 0 3 3 2 1 1 0 8 1 nd6 48 48 0 44 1 0 1 1 0 8 0 pkpcb 40 13 0 13 5 5 0 1 0 8 0 ppxss 1128 496 0 496 14 13 1 1 0 8 1 pffrag 232 3 0 3 3 3 0 1 0 482 0 pffrnode 88 3 0 3 3 3 0 1 0 8 0 pffrent 40 9 0 9 3 3 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 24 164 0 124 1 0 1 1 0 8 0 pfstkey 112 164 0 124 2 0 2 2 0 8 0 pfstate 328 164 0 124 5 0 5 5 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 1447 0 1174 20 2 18 18 0 8 0 art_table 32 1448 0 1174 3 0 3 3 0 8 0 art_node 16 612 0 572 1 0 1 1 0 8 0 sysvmsgpl 40 106 0 99 1 0 1 1 0 8 0 semupl 112 1 0 1 1 1 0 1 0 8 0 semapl 112 1509 0 1499 1 0 1 1 0 8 0 shmpl 112 128 0 0 4 0 4 4 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino1pl 128 12455 0 11045 46 0 46 46 0 8 0 ffsino 272 12455 0 11045 95 0 95 95 0 8 0 nchpl 144 23515 0 21866 62 0 62 62 0 8 0 uvmvnodes 72 5926 0 0 108 0 108 108 0 8 0 vnodes 208 5926 0 0 312 0 312 312 0 8 0 namei 1024 72265 0 72265 4 3 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 12 0 12 7 7 0 1 0 8 0 scxspl 192 64236 0 64236 21 20 1 7 0 8 1 plimitpl 152 405 0 398 1 0 1 1 0 8 0 sigapl 432 7794 0 7780 4 2 2 3 0 8 0 futexpl 56 150943 0 150943 2 1 1 1 0 8 1 knotepl 112 1049 0 1030 2 1 1 2 0 8 0 kqueuepl 104 1261 0 1259 2 1 1 2 0 8 0 pipepl 112 4184 0 4165 9 8 1 2 0 8 0 fdescpl 488 7795 0 7780 3 0 3 3 0 8 0 filepl 152 58387 0 58296 25 20 5 13 0 8 1 lockfpl 104 2785 0 2785 1 0 1 1 0 8 1 lockfspl 48 845 0 845 1 0 1 1 0 8 1 sessionpl 112 40 0 31 1 0 1 1 0 8 0 pgrppl 48 87 0 78 1 0 1 1 0 8 0 ucredpl 96 5696 0 5687 1 0 1 1 0 8 0 zombiepl 144 7783 0 7783 4 3 1 1 0 8 1 processpl 896 7814 0 7783 4 0 4 4 0 8 0 procpl 632 22397 0 22354 12 8 4 5 0 8 0 srpgc 64 46 0 46 18 17 1 1 0 8 1 sosppl 128 116 0 116 13 13 0 1 0 8 0 sockpl 384 20254 0 20232 43 39 4 22 0 8 0 mcl64k 65536 17 0 0 3 0 3 3 0 8 0 mcl16k 16384 17 0 0 3 0 3 3 0 8 1 mcl12k 12288 25 0 0 2 0 2 2 0 8 0 mcl9k 9216 21 0 0 2 0 2 2 0 8 0 mcl8k 8192 25 0 0 4 1 3 3 0 8 0 mcl4k 4096 17 0 0 3 0 3 3 0 8 0 mcl2k2 2112 7 0 0 1 0 1 1 0 8 0 mcl2k 2048 158 0 0 15 1 14 15 0 8 0 mtagpl 80 69 0 0 1 0 1 1 0 8 0 mbufpl 256 378 0 0 14 0 14 14 0 8 0 bufpl 256 17825 0 10777 441 0 441 441 0 8 0 anonpl 16 626334 0 614980 154 89 65 78 0 124 1 amapchunkpl 152 42480 0 42375 40 34 6 18 0 158 0 amappl16 192 34229 0 33340 116 70 46 55 0 8 1 amappl15 184 258 0 258 3 3 0 1 0 8 0 amappl14 176 1358 0 1354 2 1 1 1 0 8 0 amappl13 168 696 0 696 3 3 0 1 0 8 0 amappl12 160 1142 0 1140 4 3 1 1 0 8 0 amappl11 152 715 0 707 1 0 1 1 0 8 0 amappl10 144 2237 0 2233 1 0 1 1 0 8 0 amappl9 136 2020 0 2013 1 0 1 1 0 8 0 amappl8 128 1604 0 1562 2 0 2 2 0 8 0 amappl7 120 2341 0 2332 1 0 1 1 0 8 0 amappl6 112 721 0 701 1 0 1 1 0 8 0 amappl5 104 1427 0 1413 1 0 1 1 0 8 0 amappl4 96 7586 0 7555 1 0 1 1 0 8 0 amappl3 88 2373 0 2366 1 0 1 1 0 8 0 amappl2 80 60560 0 60484 4 2 2 3 0 8 0 amappl1 72 167892 0 167465 25 15 10 20 0 8 0 amappl 80 22996 0 22961 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 dma64 64 259 0 259 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 64 129 0 0 3 0 3 3 0 8 0 uaddrrnd 24 7797 0 7780 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 7797 0 7780 1 0 1 1 0 8 0 vmmpekpl 168 52060 0 52023 2 0 2 2 0 8 0 vmmpepl 168 934161 0 932084 337 216 121 121 0 357 29 vmsppl 368 7794 0 7780 2 0 2 2 0 8 0 pdppl 4096 15601 0 15564 8 3 5 6 0 8 0 pvpl 32 1740202 0 1725624 365 205 160 187 0 265 9 pmappl 232 7796 0 7782 4 3 1 2 0 8 0 extentpl 40 41 0 26 1 0 1 1 0 8 0 phpool 112 638 0 30 18 0 18 18 0 8 0