login: panic: pool_do_get: shmpl free list modified: page 0xfffffd807e1c6000; item addr 0xfffffd807e1c6d20; offset 0x10=0xdead4000 Stopped at db_enter+0x18: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND 112543 11030 0 0 0 0 syz-executor.1 *144861 11030 0 0 0x4000000 1K syz-executor.1 db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:398 panic() at panic+0x174 sys/kern/subr_prf.c:208 pool_do_get(ffffffff822f54f8,1,ffff800020c61918) at pool_do_get+0x4a3 sys/kern/subr_pool.c:750 pool_get() at pool_get+0xf7 sys/kern/subr_pool.c:587 shmget_allocate_segment(ffff800020b70720,ffff800020c61ab8,3,ffff800020c61b20) at shmget_allocate_segment+0x15e sys/kern/sysv_shm.c:409 sys_shmget(ffff800020b70720,ffff800020c61ab8,ffff800020c61b20) at sys_shmget+0x13f sys/kern/sysv_shm.c:472 syscall(ffff800020c61b90) at syscall+0x576 mi_syscall sys/sys/syscall_mi.h:99 [inline] syscall(ffff800020c61b90) at syscall+0x576 sys/arch/amd64/amd64/trap.c:574 Xsyscall(6,0,fffffffffffffff4,0,4,ca77b2e40d8) at Xsyscall+0x128 end of kernel end trace frame: 0x357, count: 7 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_do_get: shmpl free list modified: page 0xfffffd807e1c6000; item addr 0xfffffd807e1c6d20; offset 0x10=0xdead4000 ddb{1}> trace db_enter() at db_enter+0x18 sys/arch/amd64/amd64/db_interface.c:398 panic() at panic+0x174 sys/kern/subr_prf.c:208 pool_do_get(ffffffff822f54f8,1,ffff800020c61918) at pool_do_get+0x4a3 sys/kern/subr_pool.c:750 pool_get() at pool_get+0xf7 sys/kern/subr_pool.c:587 shmget_allocate_segment(ffff800020b70720,ffff800020c61ab8,3,ffff800020c61b20) at shmget_allocate_segment+0x15e sys/kern/sysv_shm.c:409 sys_shmget(ffff800020b70720,ffff800020c61ab8,ffff800020c61b20) at sys_shmget+0x13f sys/kern/sysv_shm.c:472 syscall(ffff800020c61b90) at syscall+0x576 mi_syscall sys/sys/syscall_mi.h:99 [inline] syscall(ffff800020c61b90) at syscall+0x576 sys/arch/amd64/amd64/trap.c:574 Xsyscall(6,0,fffffffffffffff4,0,4,ca77b2e40d8) at Xsyscall+0x128 end of kernel end trace frame: 0x357, count: -8 ddb{1}> show registers rdi 0xffffffff81b163d7 db_enter+0x17 rsi 0x2efd __ALIGN_SIZE+0x1efd rbp 0xffff800020c61760 rbx 0xffff800020c61810 rdx 0x2efe __ALIGN_SIZE+0x1efe rcx 0xffff800002d66000 rax 0xffff800002d66000 r8 0xffffffff815cd003 kprintf+0x173 r9 0x1 r10 0x25 r11 0xe8030ee55f4e2815 r12 0x3000000008 r13 0xffff800020c61770 r14 0x100 r15 0x1 rip 0xffffffff81b163d8 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff800020c61750 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{1}> show proc PROC (syz-executor.1) pid=144861 stat=onproc flags process=0 proc=4000000 pri=59, usrpri=59, nice=20 forw=0xffffffffffffffff, list=0xffff800020b70018,0xffff800020b70280 process=0xffff800020b9c360 user=0xffff800020c5c000, vmspace=0xfffffd807f00b438 estcpu=9, cpticks=1, pctcpu=0.0 user=0, sys=1, intr=0 ddb{1}> ps PID TID PPID UID S FLAGS WAIT COMMAND 11030 112543 13120 0 7 0 syz-executor.1 11030 176020 13120 0 3 0x4000080 fsleep syz-executor.1 *11030 144861 13120 0 7 0x4000000 syz-executor.1 11030 23236 13120 0 3 0x4000080 fsleep syz-executor.1 11030 79602 13120 0 3 0x4000080 fsleep syz-executor.1 11030 475325 13120 0 3 0x4000080 fsleep syz-executor.1 13120 512529 78602 0 3 0x82 nanosleep syz-executor.1 31157 214478 78602 0 3 0x82 piperd syz-executor.0 78602 362079 1934 0 3 0x82 kqread syz-fuzzer 78602 106757 1934 0 3 0x4000082 thrsleep syz-fuzzer 78602 410201 1934 0 3 0x4000082 thrsleep syz-fuzzer 78602 129615 1934 0 3 0x4000082 thrsleep syz-fuzzer 78602 268072 1934 0 3 0x4000082 thrsleep syz-fuzzer 78602 16909 1934 0 3 0x4000082 thrsleep syz-fuzzer 78602 447621 1934 0 3 0x4000082 thrsleep syz-fuzzer 78602 191516 1934 0 3 0x4000082 thrsleep syz-fuzzer 78602 135230 1934 0 3 0x4000082 thrsleep syz-fuzzer 78602 511543 1934 0 3 0x4000082 thrsleep syz-fuzzer 1934 440099 49112 0 3 0x10008a pause ksh 49112 257970 82933 0 3 0x92 select sshd 83727 364565 1 0 3 0x100083 ttyin getty 82933 158482 1 0 3 0x80 select sshd 68394 462765 24260 74 3 0x100092 bpf pflogd 24260 280947 1 0 3 0x80 netio pflogd 53988 77576 76298 73 3 0x100090 kqread syslogd 76298 63664 1 0 3 0x100082 netio syslogd 796 203433 1 77 3 0x100090 poll dhclient 77748 139239 1 0 3 0x80 poll dhclient 82994 3267 0 0 3 0x14200 pgzero zerothread 42779 443304 0 0 3 0x14200 aiodoned aiodoned 60151 91394 0 0 3 0x14200 syncer update 26079 432486 0 0 3 0x14200 cleaner cleaner 34579 81068 0 0 3 0x14200 reaper reaper 91866 237293 0 0 3 0x14200 pgdaemon pagedaemon 34614 18453 0 0 3 0x14200 bored crynlk 31832 511055 0 0 3 0x14200 bored crypto 88650 343275 0 0 3 0x40014200 acpi0 acpi0 68728 279491 0 0 3 0x40014200 idle1 2741 507294 0 0 3 0x14200 bored softnet 91484 42034 0 0 3 0x14200 bored systqmp 88756 93522 0 0 3 0x14200 bored systq 95593 503193 0 0 3 0x40014200 bored softclock 50356 281493 0 0 3 0x40014200 idle0 92369 220852 0 0 3 0x14200 bored smr 1 430671 0 0 3 0x82 wait init 0 0 -1 0 3 0x10200 scheduler swapper ddb{1}> show all locks CPU 1: exclusive mutex shmpl r = 0 (0xffffffff822f5508) locked @ /syzkaller/managers/multicore/kernel/sys/kern/subr_pool.c:583 #0 witness_lock+0x5a4 sys/kern/subr_witness.c:1201 #1 pool_get+0xcb sys/kern/subr_pool.c:584 #2 shmget_allocate_segment+0x15e sys/kern/sysv_shm.c:409 #3 sys_shmget+0x13f sys/kern/sysv_shm.c:472 #4 syscall+0x576 mi_syscall sys/sys/syscall_mi.h:99 [inline] #4 syscall+0x576 sys/arch/amd64/amd64/trap.c:574 #5 Xsyscall+0x128 Process 11030 (syz-executor.1) thread 0xffff800020b70720 (144861) exclusive kernel_lock &kernel_lock r = 0 (0xffffffff8230a380) locked @ /syzkaller/managers/multicore/kernel/sys/sys/syscall_mi.h:90 #0 witness_lock+0x5a4 sys/kern/subr_witness.c:1201 #1 syscall+0x45e mi_syscall sys/sys/syscall_mi.h:91 [inline] #1 syscall+0x45e sys/arch/amd64/amd64/trap.c:574 #2 Xsyscall+0x128 exclusive mutex shmpl r = 0 (0xffffffff822f5508) locked @ /syzkaller/managers/multicore/kernel/sys/kern/subr_pool.c:583 #0 witness_lock+0x5a4 sys/kern/subr_witness.c:1201 #1 pool_get+0xcb sys/kern/subr_pool.c:584 #2 shmget_allocate_segment+0x15e sys/kern/sysv_shm.c:409 #3 sys_shmget+0x13f sys/kern/sysv_shm.c:472 #4 syscall+0x576 mi_syscall sys/sys/syscall_mi.h:99 [inline] #4 syscall+0x576 sys/arch/amd64/amd64/trap.c:574 #5 Xsyscall+0x128 ddb{1}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim Kern Lim devbuf 9462 6387K 6392K 78643K 10557 0 0 pcb 25 9K 9K 78643K 59 0 0 rtable 100 3K 4K 78643K 192 0 0 ifaddr 39 10K 11K 78643K 48 0 0 counters 39 33K 33K 78643K 39 0 0 ioctlops 0 0K 4K 78643K 1469 0 0 iov 0 0K 12K 78643K 1 0 0 mount 1 1K 1K 78643K 1 0 0 vnodes 1201 75K 75K 78643K 1210 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 3 0 0 VM map 2 1K 1K 78643K 2 0 0 sem 7 0K 0K 78643K 7 0 0 dirhash 12 2K 2K 78643K 12 0 0 ACPI 1808 196K 290K 78643K 12628 0 0 file desc 5 13K 21K 78643K 32 0 0 sigio 0 0K 0K 78643K 3 0 0 proc 53 50K 71K 78643K 320 0 0 subproc 64 65538K 67586K 78643K 68 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 6 0 0 in_multi 33 2K 2K 78643K 33 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 30 132K 132K 78643K 30 0 0 exec 0 0K 1K 78643K 192 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 93 21K 21K 78643K 933 0 0 UVM aobj 4 2K 2K 78643K 5 0 0 memdesc 1 4K 4K 78643K 1 0 0 crypto data 1 1K 1K 78643K 1 0 0 NDP 10 0K 0K 78643K 12 0 0 temp 88 2364K 2433K 78643K 3213 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 47 0 38 1 0 1 1 0 8 0 plimitpl 152 15 0 7 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 tcpqe 32 6 0 6 1 0 1 1 0 8 1 tcpcb 544 16 0 10 1 0 1 1 0 8 0 nd6 48 4 0 0 1 0 1 1 0 8 0 ppxss 1128 2 0 2 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 12 0 2 1 0 1 1 0 8 0 pfstkey 112 12 0 2 1 0 1 1 0 8 0 pfstate 328 12 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 256 186 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 semapl 112 5 0 0 1 0 1 1 0 8 0 shmpl 112 3 0 1 1 0 1 1 0 8 0 shmpl: pool(0xffffffff822f54f8:shmpl): page inconsistency: page 0xfffffd807e1c6000; item ordinal 0; addr 0x91306705767d39a1 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino1pl 128 1463 0 45 46 0 46 46 0 8 0 ffsino 272 1463 0 45 95 0 95 95 0 8 0 nchpl 144 1711 0 81 61 0 61 61 0 8 0 uvmvnodes 72 1508 0 0 28 0 28 28 0 8 0 vnodes 200 1508 0 0 80 0 80 80 0 8 0 namei 1024 4306 0 4306 2 1 1 1 0 8 1 percpumem 16 30 0 0 1 0 1 1 0 8 0 scxspl 192 4348 0 4348 8 7 1 6 0 8 1 sigapl 432 231 0 216 2 0 2 2 0 8 0 futexpl 56 316 0 312 1 0 1 1 0 8 0 knotepl 112 51 0 32 1 0 1 1 0 8 0 kqueuepl 104 8 0 6 1 0 1 1 0 8 0 pipepl 112 180 0 160 3 1 2 2 0 8 1 fdescpl 488 232 0 216 3 0 3 3 0 8 0 filepl 152 1182 0 1075 5 0 5 5 0 8 0 lockfpl 104 17 0 14 2 1 1 1 0 8 0 lockfspl 32 28 0 26 2 1 1 1 0 8 0 sessionpl 112 18 0 7 1 0 1 1 0 8 0 pgrppl 48 18 0 7 1 0 1 1 0 8 0 ucredpl 96 61 0 52 1 0 1 1 0 8 0 zombiepl 144 216 0 216 2 1 1 1 0 8 1 processpl 840 247 0 216 4 0 4 4 0 8 0 procpl 600 282 0 237 4 0 4 4 0 8 0 sockpl 384 89 0 68 3 0 3 3 0 8 0 mcl4k 4096 2 0 0 1 0 1 1 0 8 0 mcl2k 2048 118 0 0 14 0 14 14 0 8 0 mtagpl 80 1 0 0 1 0 1 1 0 8 0 mbufpl 256 137 0 0 8 0 8 8 0 8 0 bufpl 256 5740 0 1165 286 0 286 286 0 8 0 anonpl 16 30912 0 21890 39 2 37 37 0 125 0 amapchunkpl 152 870 0 775 5 0 5 5 0 158 0 amappl16 192 640 0 161 24 0 24 24 0 8 0 amappl14 176 26 0 22 2 1 1 1 0 8 0 amappl13 168 6 0 6 1 1 0 1 0 8 0 amappl12 160 27 0 23 1 0 1 1 0 8 0 amappl11 152 42 0 24 1 0 1 1 0 8 0 amappl10 144 69 0 66 1 0 1 1 0 8 0 amappl9 136 571 0 568 1 0 1 1 0 8 0 amappl8 128 135 0 116 1 0 1 1 0 8 0 amappl7 120 27 0 25 1 0 1 1 0 8 0 amappl6 112 58 0 49 1 0 1 1 0 8 0 amappl5 104 140 0 125 1 0 1 1 0 8 0 amappl4 96 466 0 435 2 1 1 2 0 8 0 amappl3 88 127 0 119 1 0 1 1 0 8 0 amappl2 80 854 0 799 2 0 2 2 0 8 0 amappl1 72 14287 0 13834 26 9 17 20 0 8 7 amappl 72 516 0 477 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 4 0 1 1 0 1 1 0 8 0 uaddrrnd 24 232 0 216 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 232 0 216 1 0 1 1 0 8 0 vmmpekpl 168 5999 0 5971 2 0 2 2 0 8 0 vmmpepl 168 32417 0 30911 100 17 83 83 0 357 13 vmsppl 360 231 0 216 2 0 2 2 0 8 0 pdppl 4096 471 0 432 6 0 6 6 0 8 0 pvpl 32 119119 0 106455 108 5 103 103 0 265 0 pmappl 232 231 0 216 2 0 2 2 0 8 1 extentpl 40 39 0 25 1 0 1 1 0 8 0 phpool 112 433 0 4 13 0 13 13 0 8 0