login: panic: pool_p_free: semupl free list modified: page 0xfffffd807ebe4000; item addr 0xfffffd807ebe4d90; offset 0x0=0xdeadbef0 Stopped at db_enter+0x18: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND 30965 37714 0 0x2 0x4000080 0 syz-fuzzer *430005 38615 0 0x14000 0x200 1 systqmp db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:399 panic() at panic+0x16c sys/kern/subr_prf.c:208 pool_p_free(9909db310f3773e3,ffffffff822d8880) at pool_p_free+0x22d sys/kern/subr_pool.c:1004 pool_gc_pages(ffffffff81d6d7d0) at pool_gc_pages+0x271 sys/kern/subr_pool.c:1586 taskq_thread(0) at taskq_thread+0xd2 sys/kern/kern_task.c:309 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}> show panic pool_p_free: semupl free list modified: page 0xfffffd807ebe4000; item addr 0xfffffd807ebe4d90; offset 0x0=0xdeadbef0 ddb{1}> trace db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:399 panic() at panic+0x16c sys/kern/subr_prf.c:208 pool_p_free(9909db310f3773e3,ffffffff822d8880) at pool_p_free+0x22d sys/kern/subr_pool.c:1004 pool_gc_pages(ffffffff81d6d7d0) at pool_gc_pages+0x271 sys/kern/subr_pool.c:1586 taskq_thread(0) at taskq_thread+0xd2 sys/kern/kern_task.c:309 end trace frame: 0x0, count: -5 ddb{1}> show registers rdi 0 rsi 0x1 rbp 0xffff800020b3b2c0 rbx 0xffff800020b3b360 rdx 0xffffffff81f35469 cy_pio_rec+0x2087 rcx 0 rax 0 r8 0xffffffff81d85b34 kprintf+0x174 r9 0x1 r10 0xb603b56191ec8ea1 r11 0x47de210d98922c04 r12 0x3000000008 r13 0xffff800020b3b2d0 r14 0x100 r15 0x1 rip 0xffffffff81bb44e8 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff800020b3b2b0 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{1}> show proc PROC (systqmp) pid=430005 stat=onproc flags process=14000 proc=200 pri=32, usrpri=50, nice=20 forw=0xffffffffffffffff, list=0xffff800020b21518,0xffff800020b20e20 process=0xffff800020b22000 user=0xffff800020b36000, vmspace=0xffffffff822e71c8 estcpu=0, cpticks=1, pctcpu=0.0 user=0, sys=1, intr=0 ddb{1}> ps PID TID PPID UID S FLAGS WAIT COMMAND 35102 292510 1 0 3 0x100083 ttyin getty 10609 384909 0 0 3 0x14200 bored sosplice 83244 494350 37714 0 2 0x482 syz-executor1 92875 357017 37714 0 2 0x2 syz-executor0 37714 262161 27010 0 3 0x82 thrsleep syz-fuzzer 37714 404967 27010 0 3 0x4000082 thrsleep syz-fuzzer 37714 489086 27010 0 3 0x4000082 thrsleep syz-fuzzer 37714 145042 27010 0 3 0x4000082 thrsleep syz-fuzzer 37714 79409 27010 0 3 0x4000082 thrsleep syz-fuzzer 37714 155764 27010 0 3 0x4000082 thrsleep syz-fuzzer 37714 467893 27010 0 3 0x4000082 thrsleep syz-fuzzer 37714 473622 27010 0 3 0x4000082 thrsleep syz-fuzzer 37714 428999 27010 0 3 0x4000082 thrsleep syz-fuzzer 37714 30965 27010 0 7 0x4000082 syz-fuzzer 37714 267530 27010 0 3 0x4000082 thrsleep syz-fuzzer 27010 152635 91669 0 3 0x10008a pause ksh 91669 339944 11500 0 3 0x92 select sshd 11500 96921 1 0 3 0x80 select sshd 31202 444306 82381 73 3 0x100090 kqread syslogd 82381 83878 1 0 3 0x100082 netio syslogd 68186 128532 1 77 3 0x100090 poll dhclient 74043 473626 1 0 3 0x80 poll dhclient 61825 115098 0 0 3 0x14200 pgzero zerothread 75479 212998 0 0 3 0x14200 aiodoned aiodoned 70246 345765 0 0 2 0x14200 update 75048 523174 0 0 3 0x14200 cleaner cleaner 13128 33756 0 0 3 0x14200 reaper reaper 56939 518364 0 0 3 0x14200 pgdaemon pagedaemon 46476 150946 0 0 3 0x14200 bored crynlk 53210 337504 0 0 3 0x14200 bored crypto 35611 463024 0 0 3 0x40014200 acpi0 acpi0 70802 386081 0 0 3 0x40014200 idle1 13804 150207 0 0 3 0x14200 bored softnet *38615 430005 0 0 7 0x14200 systqmp 13553 130210 0 0 3 0x14200 bored systq 34214 512474 0 0 3 0x40014200 bored softclock 29225 166720 0 0 3 0x40014200 idle0 1 127840 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb{1}> show all locks Process 38615 (systqmp) thread 0xffff800020b21068 (430005) shared rwlock pools r = 0 (0xffffffff821828f0) locked @ /syzkaller/managers/multicore/kernel/sys/kern/subr_pool.c:1562 ddb{1}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim Kern Lim devbuf 9503 6355K 6361K 78643K 10933 0 0 pcb 23 9K 10K 78643K 567 0 0 rtable 100 3K 4K 78643K 328 0 0 ifaddr 51 13K 13K 78643K 142 0 0 counters 39 33K 33K 78643K 39 0 0 ioctlops 0 0K 2K 78643K 29 0 0 iov 0 0K 16K 78643K 122 0 0 mount 1 1K 1K 78643K 1 0 0 vnodes 1211 76K 76K 78643K 1921 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 16 0 0 VM map 2 1K 1K 78643K 2 0 0 sem 12 0K 0K 78643K 120 0 0 dirhash 12 2K 2K 78643K 12 0 0 ACPI 1792 194K 288K 78643K 12592 0 0 file desc 4 9K 25K 78643K 1058 0 0 sigio 0 0K 0K 78643K 29 0 0 proc 42 38K 70K 78643K 441 0 0 subproc 64 65538K 67586K 78643K 86 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 136 0 0 in_multi 33 2K 2K 78643K 71 0 0 ether_multi 1 0K 0K 78643K 7 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 263 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 81 20K 29K 78643K 4183 0 0 UVM aobj 55 5K 5K 78643K 62 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 24 0 0 NDP 9 0K 0K 78643K 38 0 0 temp 149 2366K 2433K 78643K 5631 0 0 kqueue 0 0K 0K 78643K 13 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 0 1 0 1 1 0 8 0 inpcbpl 280 520 0 513 1 0 1 1 0 8 0 plimitpl 152 25 0 18 1 0 1 1 0 8 0 plcache 128 20 0 0 1 0 1 1 0 8 0 rtentry 112 41 0 1 2 0 2 2 0 8 0 syncache 264 4 0 4 1 1 0 1 0 8 0 tcpcb 544 215 0 211 1 0 1 1 0 8 0 nd6 48 4 0 0 1 0 1 1 0 8 0 ppxss 1128 19 0 19 5 5 0 1 0 8 0 art_heap8 4096 1 0 0 1 0 1 1 0 8 0 art_heap4 256 186 0 0 12 0 12 12 0 8 0 art_table 32 187 0 0 2 0 2 2 0 8 0 art_node 16 40 0 6 1 0 1 1 0 8 0 sysvmsgpl 40 14 0 6 1 0 1 1 0 8 0 semupl 112 1 0 1 1 1 0 1 0 8 0 semapl 112 114 0 104 1 0 1 1 0 8 0 shmpl 112 60 0 7 2 0 2 2 0 8 0 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino1pl 128 3530 0 2130 46 0 46 46 0 8 0 ffsino 272 3530 0 2130 94 0 94 94 0 8 0 nchpl 144 5225 0 3636 59 0 59 59 0 8 0 uvmvnodes 72 3678 0 0 67 0 67 67 0 8 0 vnodes 200 3678 0 0 194 0 194 194 0 8 0 namei 1024 15477 0 15477 2 1 1 1 0 8 1 percpumem 16 30 0 0 1 0 1 1 0 8 0 scsiplug 64 4 0 4 3 3 0 1 0 8 0 scxspl 192 13278 0 13278 10 9 1 6 0 8 1 sigapl 432 1228 0 1216 2 0 2 2 0 8 0 futexpl 56 13335 0 13335 1 0 1 1 0 8 1 knotepl 112 296 0 269 2 1 1 2 0 8 0 kqueuepl 104 345 0 343 1 0 1 1 0 8 0 pipepl 112 866 0 847 4 3 1 2 0 8 0 fdescpl 488 1229 0 1216 3 1 2 3 0 8 0 filepl 152 7960 0 7866 6 1 5 5 0 8 1 lockfpl 104 370 0 370 3 2 1 1 0 8 1 lockfspl 32 368 0 368 3 2 1 1 0 8 1 sessionpl 112 20 0 10 1 0 1 1 0 8 0 pgrppl 48 26 0 16 1 0 1 1 0 8 0 ucredpl 96 2368 0 2361 1 0 1 1 0 8 0 zombiepl 144 1216 0 1215 2 1 1 1 0 8 0 processpl 840 1244 0 1215 4 0 4 4 0 8 0 procpl 600 3549 0 3510 4 0 4 4 0 8 0 sosppl 128 23 0 23 5 4 1 1 0 8 1 sockpl 384 1043 0 1026 4 1 3 4 0 8 1 mcl64k 65536 289 0 0 36 7 29 30 0 8 1 mcl16k 16384 2 0 0 1 0 1 1 0 8 0 mcl12k 12288 14 0 0 2 0 2 2 0 8 0 mcl9k 9216 9 0 0 1 0 1 1 0 8 0 mcl8k 8192 12 0 0 2 0 2 2 0 8 0 mcl4k 4096 15 0 0 2 0 2 2 0 8 0 mcl2k2 2112 7 0 0 1 0 1 1 0 8 0 mcl2k 2048 111 0 0 13 0 13 13 0 8 0 mtagpl 80 1 0 0 1 0 1 1 0 8 0 mbufpl 256 396 0 0 20 0 20 20 0 8 0 bufpl 256 6774 0 975 363 0 363 363 0 8 0 anonpl 16 120062 0 112376 78 38 40 48 0 125 7 amapchunkpl 152 7190 0 7110 21 12 9 9 0 158 4 amappl16 192 6296 0 5885 46 24 22 33 0 8 0 amappl15 184 1 0 0 1 0 1 1 0 8 0 amappl14 176 3 0 2 2 1 1 1 0 8 0 amappl13 168 19 0 16 1 0 1 1 0 8 0 amappl12 160 550 0 549 1 0 1 1 0 8 0 amappl11 152 188 0 178 1 0 1 1 0 8 0 amappl10 144 63 0 62 2 1 1 1 0 8 0 amappl9 136 297 0 296 1 0 1 1 0 8 0 amappl8 128 705 0 680 1 0 1 1 0 8 0 amappl7 120 35 0 29 1 0 1 1 0 8 0 amappl6 112 52 0 44 1 0 1 1 0 8 0 amappl5 104 224 0 213 1 0 1 1 0 8 0 amappl4 96 792 0 770 2 1 1 2 0 8 0 amappl3 88 194 0 188 1 0 1 1 0 8 0 amappl2 80 11081 0 11038 2 0 2 2 0 8 0 amappl1 72 34616 0 34220 23 13 10 18 0 8 0 amappl 72 3782 0 3752 1 0 1 1 0 75 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 61 0 7 1 0 1 1 0 8 0 uaddrrnd 24 1229 0 1216 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 1229 0 1216 1 0 1 1 0 8 0 vmmpekpl 168 14400 0 14377 2 0 2 2 0 8 0 vmmpepl 168 135310 0 134051 103 38 65 75 0 357 0 vmsppl 360 1228 0 1216 2 0 2 2 0 8 0 pdppl 4096 2465 0 2432 6 1 5 6 0 8 0 pvpl 32 344820 0 334227 169 61 108 126 0 265 16 pmappl 224 1228 0 1216 1 0 1 1 0 8 0 extentpl 40 39 0 25 1 0 1 1 0 8 0 phpool 112 558 0 11 16 0 16 16 0 8 0