panic: pool_p_free: pffrnode free list modified: page 0xfffffd807b1b6000; item addr 0xfffffd807b1b6000; offset 0x0=0x0 Stopped at db_enter+0x18: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND 329975 82728 0 0x2 0x4000080 0 syz-fuzzer * 600 97799 0 0x14000 0x200 1 systqmp db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:398 panic(ffffffff8222a27c) at panic+0x15c sys/kern/subr_prf.c:207 pool_p_free(ffffffff82621500,fffffd807b1b6f90) at pool_p_free+0x1de sys/kern/subr_pool.c:991 pool_gc_pages(0) at pool_gc_pages+0x255 sys/kern/subr_pool.c:1586 taskq_thread(ffffffff82464cf0) at taskq_thread+0x9c sys/kern/kern_task.c:369 end trace frame: 0x0, count: 10 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_p_free: pffrnode free list modified: page 0xfffffd807b1b6000; item addr 0xfffffd807b1b6000; offset 0x0=0x0 ddb{1}> trace db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:398 panic(ffffffff8222a27c) at panic+0x15c sys/kern/subr_prf.c:207 pool_p_free(ffffffff82621500,fffffd807b1b6f90) at pool_p_free+0x1de sys/kern/subr_pool.c:991 pool_gc_pages(0) at pool_gc_pages+0x255 sys/kern/subr_pool.c:1586 taskq_thread(ffffffff82464cf0) at taskq_thread+0x9c sys/kern/kern_task.c:369 end trace frame: 0x0, count: -5 ddb{1}> show registers rdi 0 rsi 0x1 rbp 0xffff800020a49a30 rbx 0xffff800020a49ae0 rdx 0xffff800020a284f0 rcx 0 rax 0 r8 0xffffffff8176834f kprintf+0x16f r9 0x1 r10 0x25 r11 0x7857bf8d48502a07 r12 0x3000000008 r13 0xffff800020a49a40 r14 0x100 r15 0x1 rip 0xffffffff81c0cd88 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff800020a49a20 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{1}> show proc PROC (systqmp) pid=600 stat=onproc flags process=14000 proc=200 pri=32, usrpri=51, nice=20 forw=0xffffffffffffffff, list=0xffff800020a289e0,0xffff800020a28010 process=0xffff800020a2aa80 user=0xffff800020a44000, vmspace=0xffffffff8264c070 estcpu=1, cpticks=2, pctcpu=0.0 user=0, sys=2, intr=0 ddb{1}> ps PID TID PPID UID S FLAGS WAIT COMMAND 48665 410705 81569 0 2 0 syz-executor.0 48665 135564 81569 0 2 0x4000000 syz-executor.0 67469 489398 0 0 3 0x14200 acct acct 39219 242468 0 0 3 0x14200 bored sosplice 28035 163511 82728 0 3 0x2 biowait syz-executor.1 81569 379878 82728 0 2 0x2 syz-executor.0 82728 126675 78802 0 3 0x82 nanosleep syz-fuzzer 82728 248201 78802 0 2 0x4000082 syz-fuzzer 82728 275930 78802 0 3 0x4000082 thrsleep syz-fuzzer 82728 293522 78802 0 2 0x4000482 syz-fuzzer 82728 522734 78802 0 3 0x4000082 thrsleep syz-fuzzer 82728 329975 78802 0 7 0x4000082 syz-fuzzer 82728 277384 78802 0 3 0x4000082 thrsleep syz-fuzzer 82728 158775 78802 0 2 0x4000002 syz-fuzzer 82728 187046 78802 0 3 0x4000082 kqread syz-fuzzer 82728 54374 78802 0 3 0x4000082 thrsleep syz-fuzzer 78802 165680 9365 0 3 0x10008a pause ksh 9365 231229 5890 0 3 0x92 select sshd 17473 276325 1 0 3 0x100083 ttyin getty 5890 500487 1 0 3 0x80 select sshd 62060 382547 1194 74 3 0x100092 bpf pflogd 1194 216810 1 0 3 0x80 netio pflogd 95783 190928 77603 73 3 0x100090 kqread syslogd 77603 240289 1 0 3 0x100082 netio syslogd 78408 296369 0 0 3 0x14200 pgzero zerothread 95356 2285 0 0 3 0x14200 aiodoned aiodoned 50136 77902 0 0 2 0x14200 update 44297 58641 0 0 3 0x14200 cleaner cleaner 98388 29069 0 0 3 0x14200 reaper reaper 3514 478784 0 0 3 0x14200 pgdaemon pagedaemon 96439 147736 0 0 3 0x14200 bored crynlk 23524 237596 0 0 3 0x14200 bored crypto 9398 132564 0 0 3 0x40014200 acpi0 acpi0 63403 137668 0 0 3 0x40014200 idle1 37385 67631 0 0 3 0x14200 bored softnet *97799 600 0 0 7 0x14200 systqmp 44112 481840 0 0 3 0x14200 bored systq 63253 47267 0 0 3 0x40014200 bored softclock 99219 355554 0 0 3 0x40014200 idle0 48601 281132 0 0 2 0x40014200 smr 1 241338 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb{1}> show all locks Process 28035 (syz-executor.1) thread 0xffff800020ad7160 (163511) exclusive rrwlock inode r = 0 (0xfffffd80669e6e70) #0 witness_lock+0x52e sys/kern/subr_witness.c:1163 #1 rw_enter+0x453 sys/kern/kern_rwlock.c:309 #2 rrw_enter+0x88 sys/kern/kern_rwlock.c:453 #3 ufs_ihashins+0x45 sys/ufs/ufs/ufs_ihash.c:140 #4 ffs_vget+0x13e sys/ufs/ffs/ffs_vfsops.c:1352 #5 ffs_inode_alloc+0x1cf sys/ufs/ffs/ffs_alloc.c:392 #6 ufs_mkdir+0xf4 sys/ufs/ufs/ufs_vnops.c:1164 #7 VOP_MKDIR+0xc6 sys/kern/vfs_vops.c:450 #8 domkdirat+0x121 sys/kern/vfs_syscalls.c:2974 #9 syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:92 [inline] #9 syscall+0x4a4 sys/arch/amd64/amd64/trap.c:570 #10 Xsyscall+0x128 exclusive rrwlock inode r = 0 (0xfffffd806acc1918) #0 witness_lock+0x52e sys/kern/subr_witness.c:1163 #1 rw_enter+0x453 sys/kern/kern_rwlock.c:309 #2 rrw_enter+0x88 sys/kern/kern_rwlock.c:453 #3 VOP_LOCK+0xf9 sys/kern/vfs_vops.c:615 #4 vn_lock+0x81 sys/kern/vfs_vnops.c:571 #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:2959 #8 syscall+0x4a4 mi_syscall sys/sys/syscall_mi.h:92 [inline] #8 syscall+0x4a4 sys/arch/amd64/amd64/trap.c:570 #9 Xsyscall+0x128 Process 82728 (syz-fuzzer) thread 0xffff800020a77b30 (158775) exclusive kernel_lock &kernel_lock r = 0 (0xffffffff82626628) #0 witness_lock+0x52e sys/kern/subr_witness.c:1163 #1 syscall+0x400 mi_syscall sys/sys/syscall_mi.h:83 [inline] #1 syscall+0x400 sys/arch/amd64/amd64/trap.c:570 #2 Xsyscall+0x128 Process 97799 (systqmp) thread 0xffff800020a284f0 (600) shared rwlock pools r = 0 (0xffffffff824d9970) #0 witness_lock+0x52e sys/kern/subr_witness.c:1163 #1 pool_gc_pages+0x21 sys/kern/subr_pool.c:1563 #2 taskq_thread+0x9c sys/kern/kern_task.c:369 #3 proc_trampoline+0x1c shared rwlock systqmp r = 0 (0xffffffff82464d50) #0 witness_lock+0x52e sys/kern/subr_witness.c:1163 #1 taskq_thread+0x8f sys/kern/kern_task.c:368 #2 proc_trampoline+0x1c ddb{1}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim devbuf 9522 6488K 6805K 78643K 11075 0 pcb 13 8K 8K 78643K 80 0 rtable 105 4K 5K 78643K 333 0 ifaddr 80 16K 16K 78643K 124 0 counters 39 33K 33K 78643K 39 0 ioctlops 0 0K 4K 78643K 1491 0 iov 0 0K 24K 78643K 60 0 mount 1 1K 1K 78643K 1 0 vnodes 1219 77K 77K 78643K 1356 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 46 0 dirhash 12 2K 2K 78643K 12 0 ACPI 1809 196K 290K 78643K 12766 0 file desc 5 13K 25K 78643K 244 0 sigio 0 0K 0K 78643K 14 0 proc 56 51K 83K 78643K 461 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 1K 78643K 65 0 in_multi 67 3K 3K 78643K 94 0 ether_multi 1 0K 0K 78643K 8 0 mrt 0 0K 0K 78643K 3 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 225 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 104 21K 37K 78643K 1754 0 UVM aobj 18 2K 2K 78643K 19 0 memdesc 1 4K 4K 78643K 1 0 crypto data 1 1K 1K 78643K 1 0 ip6_options 0 0K 0K 78643K 34 0 NDP 12 0K 0K 78643K 24 0 temp 123 3016K 3085K 78643K 8185 0 kqueue 3 4K 12K 78643K 18 0 SYN cache 2 16K 16K 78643K 2 0 ddb{1}> show all pools Name Size Requests Fail Releases Pgreq Pgrel Npage Hiwat Minpg Maxpg Idle arp 64 6 0 1 1 0 1 1 0 8 0 plcache 128 20 0 0 1 0 1 1 0 8 0 rtpcb 80 53 0 53 1 0 1 1 0 8 1 rtentry 112 52 0 11 2 0 2 2 0 8 0 unpcb 120 299 0 291 1 0 1 1 0 8 0 syncache 264 4 0 4 1 1 0 1 0 8 0 sackhl 24 1 0 1 1 1 0 1 0 8 0 tcpcb 544 102 0 98 1 0 1 1 0 8 0 inpcb 280 575 0 571 3 0 3 3 0 8 2 rttmr 72 1 0 1 1 1 0 1 0 8 0 nd6 48 5 0 2 1 0 1 1 0 8 0 pkpcb 40 2 0 2 1 0 1 1 0 8 1 ppxss 1128 5 0 5 1 0 1 1 0 8 1 pffrag 232 2 0 2 1 1 0 1 0 482 0 pffrnode 88 2 0 2 1 1 0 1 0 8 0 pffrent 40 90 0 90 1 0 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 pfstitem 24 37 0 0 1 0 1 1 0 8 0 pfstkey 112 37 0 0 2 0 2 2 0 8 0 pfstate 328 37 0 0 4 0 4 4 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 256 242 0 41 14 0 14 14 0 8 1 art_table 32 243 0 41 2 0 2 2 0 8 0 art_node 16 51 0 13 1 0 1 1 0 8 0 sysvmsgpl 40 40 0 14 1 0 1 1 0 8 0 semupl 112 1 0 1 1 1 0 1 0 8 0 semapl 112 44 0 34 1 0 1 1 0 8 0 shmpl 112 17 0 1 1 0 1 1 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino1pl 128 1749 0 340 46 0 46 46 0 8 0 ffsino 272 1749 0 340 95 0 95 95 0 8 0 nchpl 144 2328 0 710 61 0 61 61 0 8 0 uvmvnodes 72 1893 0 0 35 0 35 35 0 8 0 vnodes 208 1893 0 0 100 0 100 100 0 8 0 namei 1024 6506 0 6505 1 0 1 1 0 8 0 percpumem 16 30 0 0 1 0 1 1 0 8 0 vmpool 560 2 0 2 1 0 1 1 0 8 1 scxspl 192 6452 0 6451 8 3 5 7 0 8 4 plimitpl 152 37 0 30 1 0 1 1 0 8 0 sigapl 432 443 0 430 3 1 2 3 0 8 0 futexpl 56 5270 0 5270 1 0 1 1 0 8 1 knotepl 112 70 0 51 1 0 1 1 0 8 0 kqueuepl 104 52 0 50 1 0 1 1 0 8 0 pipelkpl 48 176 0 166 1 0 1 1 0 8 0 pipepl 120 352 0 333 2 0 2 2 0 8 1 fdescpl 496 444 0 430 3 0 3 3 0 8 0 filepl 152 3324 0 3234 7 1 6 7 0 8 2 lockfpl 104 72 0 72 1 0 1 1 0 8 1 lockfspl 48 26 0 26 1 0 1 1 0 8 1 sessionpl 112 18 0 9 1 0 1 1 0 8 0 pgrppl 48 22 0 13 1 0 1 1 0 8 0 ucredpl 96 277 0 269 1 0 1 1 0 8 0 zombiepl 144 430 0 430 1 0 1 1 0 8 1 processpl 896 461 0 430 4 0 4 4 0 8 0 procpl 632 987 0 946 5 0 5 5 0 8 1 sosppl 128 4 0 4 1 0 1 1 0 8 1 sockpl 400 931 0 919 6 1 5 5 0 8 3 mcl64k 65536 7 0 0 1 0 1 1 0 8 0 mcl16k 16384 1 0 0 1 0 1 1 0 8 0 mcl12k 12288 1 0 0 1 0 1 1 0 8 0 mcl9k 9216 4 0 0 1 0 1 1 0 8 0 mcl8k 8192 3 0 0 1 0 1 1 0 8 0 mcl4k 4096 10 0 0 2 0 2 2 0 8 0 mcl2k2 2112 1 0 0 1 0 1 1 0 8 0 mcl2k 2048 155 0 0 19 0 19 19 0 8 0 mtagpl 80 22 0 0 1 0 1 1 0 8 0 mbufpl 256 360 0 0 22 0 22 22 0 8 0 bufpl 280 6724 0 1340 385 0 385 385 0 8 0 anonpl 16 54620 0 39109 72 1 71 71 0 125 7 amapchunkpl 152 2417 0 2289 12 1 11 11 0 158 4 amappl16 192 1879 0 1029 45 0 45 45 0 8 2 amappl15 184 59 0 55 1 0 1 1 0 8 0 amappl14 176 28 0 26 2 1 1 1 0 8 0 amappl12 160 115 0 112 2 1 1 1 0 8 0 amappl11 152 158 0 148 1 0 1 1 0 8 0 amappl10 144 12 0 7 1 0 1 1 0 8 0 amappl9 136 605 0 601 1 0 1 1 0 8 0 amappl8 128 116 0 96 1 0 1 1 0 8 0 amappl7 120 104 0 92 1 0 1 1 0 8 0 amappl6 112 158 0 150 1 0 1 1 0 8 0 amappl5 104 235 0 224 1 0 1 1 0 8 0 amappl4 96 591 0 566 1 0 1 1 0 8 0 amappl3 88 228 0 220 1 0 1 1 0 8 0 amappl2 80 2641 0 2577 3 1 2 3 0 8 0 amappl1 72 19946 0 19525 27 17 10 21 0 8 0 amappl 80 1234 0 1194 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 18 0 1 1 0 1 1 0 8 0 uaddrrnd 24 446 0 432 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 446 0 432 1 0 1 1 0 8 0 vmmpekpl 168 7294 0 7260 2 0 2 2 0 8 0 vmmpepl 168 61704 0 59766 118 11 107 111 0 357 18 vmsppl 368 445 0 432 2 0 2 2 0 8 0 pdppl 4096 899 0 864 6 0 6 6 0 8 1 pvpl 32 179271 0 160671 172 0 172 172 0 265 20 pmappl 232 445 0 432 2 1 1 2 0 8 0 extentpl 40 46 0 29 1 0 1 1 0 8 0 phpool 112 179 0 4 6 0 6 6 0 8 0