panic: pool_do_get: shmpl free list modified: page 0xfffffd806b91e000; item addr 0xfffffd806b91eb60; offset 0x40=0x67ac15c9 Stopped at db_enter+0x25: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND 304812 39030 32767 0x10 0 0 syz-executor *128702 39030 32767 0x10 0x4000000 1K syz-executor db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:437 panic(ffffffff833a8df1) at panic+0x1e5 sys/kern/subr_prf.c:198 pool_do_get(ffffffff83899b58,1,ffff8000358cc468) at pool_do_get+0x5da pool_get(ffffffff83899b58,1) at pool_get+0x149 shmget_allocate_segment(ffff8000ffff4028,ffff8000358cc6c0,0,ffff8000358cc610) at shmget_allocate_segment+0x1a7 sys_shmget(ffff8000ffff4028,ffff8000358cc6c0,ffff8000358cc610) at sys_shmget+0x1b2 sys/kern/sysv_shm.c:482 syscall(ffff8000358cc6c0) at syscall+0xb08 mi_syscall sys/sys/syscall_mi.h:176 [inline] syscall(ffff8000358cc6c0) at syscall+0xb08 sys/arch/amd64/amd64/trap.c:577 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x77e8d1e5310, 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 *cpu1: pool_do_get: shmpl free list modified: page 0xfffffd806b91e000; item addr 0xfffffd806b91eb60; offset 0x40=0x67ac15c9 ddb{1}> trace db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:437 panic(ffffffff833a8df1) at panic+0x1e5 sys/kern/subr_prf.c:198 pool_do_get(ffffffff83899b58,1,ffff8000358cc468) at pool_do_get+0x5da pool_get(ffffffff83899b58,1) at pool_get+0x149 shmget_allocate_segment(ffff8000ffff4028,ffff8000358cc6c0,0,ffff8000358cc610) at shmget_allocate_segment+0x1a7 sys_shmget(ffff8000ffff4028,ffff8000358cc6c0,ffff8000358cc610) at sys_shmget+0x1b2 sys/kern/sysv_shm.c:482 syscall(ffff8000358cc6c0) at syscall+0xb08 mi_syscall sys/sys/syscall_mi.h:176 [inline] syscall(ffff8000358cc6c0) at syscall+0xb08 sys/arch/amd64/amd64/trap.c:577 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x77e8d1e5310, count: -8 ddb{1}> show registers rdi 0 rsi 0x1 rbp 0xffff8000358cc2a0 rbx 0xffff800029aacdc7 rdx 0xffff800001423580 rcx 0xffff8000ffff4028 rax 0xffff800029aabff0 r8 0x101010101010101 r9 0x8080808080808080 r10 0x4e917e02051eb4b4 r11 0x23c3ff42708390 r12 0xffff800029aacbc8 r13 0 r14 0 r15 0x1 rip 0xffffffff8177b775 db_enter+0x25 cs 0x8 rflags 0x246 rsp 0xffff8000358cc290 ss 0x10 db_enter+0x25: addq $0x8,%rsp ddb{1}> show proc PROC (syz-executor) tid=128702 pid=39030 tcnt=2 stat=onproc flags process=10 proc=4000000 runpri=50, usrpri=50, slppri=16, nice=20 wchan=0x0, wmesg=, ps_single=0x0 scnt=0 ecnt=0 forw=0xffffffffffffffff, list=0xffff8000ffff54a8,0xffffffff8395e0c8 process=0xffff80003c5006e0 user=0xffff8000358c7000, vmspace=0xfffffd806bf10ca0 estcpu=36, cpticks=1, pctcpu=0.0, user=0, sys=1, intr=0 ddb{1}> ps PID TID PPID UID S FLAGS WAIT COMMAND 24532 187161 36377 32767 2 0x10 syz-executor 24532 509951 36377 32767 3 0x4000090 fsleep syz-executor 39030 304812 78220 32767 7 0x10 syz-executor *39030 128702 78220 32767 7 0x4000010 syz-executor 53311 364494 62448 0 2 0x2 syz-executor 80307 8064 81371 32767 3 0x90 nanoslp syz-executor 80307 121318 81371 32767 3 0x4000090 kqsel syz-executor 80307 61537 81371 32767 3 0x4000090 fsleep syz-executor 40741 172862 70020 32767 3 0x90 nanoslp syz-executor 40741 65477 70020 32767 3 0x4000090 sbwait syz-executor 46833 259331 0 0 3 0x14200 bored sosplice 81371 26168 59722 32767 3 0x90 nanoslp syz-executor 61009 204135 14402 32767 3 0x90 piperd syz-executor 70020 453506 24169 32767 3 0x90 nanoslp syz-executor 4743 325011 79416 32767 3 0x90 piperd syz-executor 393 354206 72165 32767 3 0x90 piperd syz-executor 36377 105064 24976 32767 3 0x90 nanoslp syz-executor 78220 18412 92757 32767 3 0x90 nanoslp syz-executor 59722 379338 62448 0 3 0x82 wait syz-executor 14402 492010 62448 0 3 0x82 wait syz-executor 72165 435404 62448 0 3 0x82 wait syz-executor 79416 499988 62448 0 3 0x82 wait syz-executor 24169 440005 62448 0 3 0x82 wait syz-executor 24976 437492 62448 0 3 0x82 wait syz-executor 92757 142215 62448 0 3 0x82 wait syz-executor 62448 376079 94611 0 2 0x2 syz-executor 94611 186968 32140 0 3 0x10008a sigsusp ksh 32140 419813 16246 0 3 0x98 kqread sshd-session 16246 308844 9778 0 3 0x92 kqread sshd-session 98081 275840 1 0 3 0x100083 ttyin getty 9778 483154 1 0 3 0x88 kqread sshd 11715 520025 65194 73 3 0x1100090 kqread syslogd 65194 384587 1 0 3 0x100082 sbwait syslogd 31676 479551 1 0 3 0x100080 kqread resolvd 58032 49459 3437 77 3 0x100092 kqread dhcpleased 10163 261528 3437 77 3 0x100092 kqread dhcpleased 3437 487159 1 0 3 0x80 kqread dhcpleased 6812 235313 0 0 3 0x14200 bored smr 36788 238556 0 0 2 0x14200 zerothread 77579 504040 0 0 3 0x14200 aiodoned aiodoned 92768 206939 0 0 3 0x14200 syncer update 39746 279398 0 0 3 0x14200 cleaner cleaner 1648 430734 0 0 3 0x14200 reaper reaper 88977 22898 0 0 3 0x14200 pgdaemon pagedaemon 72892 105893 0 0 3 0x14200 bored viomb 88452 392685 0 0 3 0x40014200 acpi0 acpi0 27994 472442 0 0 3 0x40014200 idle1 76919 229333 0 0 3 0x14200 bored softnet3 34123 82185 0 0 3 0x14200 bored softnet2 37075 248435 0 0 3 0x14200 bored softnet1 2626 209811 0 0 3 0x14200 bored softnet0 68521 359758 0 0 3 0x14200 bored systqmp 86267 346316 0 0 3 0x14200 bored systq 85173 517163 0 0 3 0x14200 tmoslp softclockmp 25595 14575 0 0 3 0x40014200 tmoslp softclock 2002 4842 0 0 3 0x40014200 idle0 1 372983 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 (0xffffffff83899b70) #0 witness_lock+0x5bb stacktrace_save sys/sys/stacktrace.h:37 [inline] #0 witness_lock+0x5bb sys/kern/subr_witness.c:1155 #1 mtx_enter_try+0x178 #2 mtx_enter+0x60 sys/kern/kern_lock.c:239 #3 pool_get+0x10b sys/kern/subr_pool.c:583 #4 shmget_allocate_segment+0x1a7 #5 sys_shmget+0x1b2 sys/kern/sysv_shm.c:482 #6 syscall+0xb08 mi_syscall sys/sys/syscall_mi.h:176 [inline] #6 syscall+0xb08 sys/arch/amd64/amd64/trap.c:577 #7 Xsyscall+0x128 Process 39030 (syz-executor) thread 0xffff8000ffff4028 (128702) exclusive kernel_lock &kernel_lock r = 0 (0xffffffff838e8630) #0 witness_lock+0x5bb stacktrace_save sys/sys/stacktrace.h:37 [inline] #0 witness_lock+0x5bb sys/kern/subr_witness.c:1155 #1 syscall+0xae6 mi_syscall sys/sys/syscall_mi.h:176 [inline] #1 syscall+0xae6 sys/arch/amd64/amd64/trap.c:577 #2 Xsyscall+0x128 exclusive mutex shmpl r = 0 (0xffffffff83899b70) #0 witness_lock+0x5bb stacktrace_save sys/sys/stacktrace.h:37 [inline] #0 witness_lock+0x5bb sys/kern/subr_witness.c:1155 #1 mtx_enter_try+0x178 #2 mtx_enter+0x60 sys/kern/kern_lock.c:239 #3 pool_get+0x10b sys/kern/subr_pool.c:583 #4 shmget_allocate_segment+0x1a7 #5 sys_shmget+0x1b2 sys/kern/sysv_shm.c:482 #6 syscall+0xb08 mi_syscall sys/sys/syscall_mi.h:176 [inline] #6 syscall+0xb08 sys/arch/amd64/amd64/trap.c:577 #7 Xsyscall+0x128 ddb{1}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim devbuf 10186 10952K 10966K 166960K 11268 0 pcb 17 12K 12K 166960K 17 0 rtable 218 6K 6K 166960K 359 0 pf 29 16K 16K 166960K 31 0 ifaddr 38 6K 7K 166960K 44 0 ifgroup 46 2K 2K 166960K 50 0 sysctl 3 1K 1K 166960K 3 0 counters 62 36K 36K 166960K 64 0 ioctlops 0 0K 2K 166960K 31 0 iov 0 0K 12K 166960K 9 0 mount 1 1K 1K 166960K 1 0 log 0 0K 0K 166960K 4 0 vnodes 1332 84K 84K 166960K 1396 0 UFS quota 1 32K 32K 166960K 1 0 UFS mount 5 36K 36K 166960K 5 0 shm 2 1K 9K 166960K 9 0 VM map 2 1K 1K 166960K 2 0 sem 6 0K 0K 166960K 6 0 dirhash 12 2K 2K 166960K 24 0 ACPI 1692 195K 286K 166960K 12470 0 file desc 21 77K 125K 166960K 280 0 sigio 0 0K 0K 166960K 2 0 proc 65 91K 115K 166960K 491 0 subproc 65 4K 4K 166960K 110 0 NFS srvsock 1 0K 0K 166960K 1 0 NFS daemon 1 16K 16K 166960K 1 0 ip_moptions 2 0K 0K 166960K 24 0 in_multi 89 6K 7K 166960K 113 0 ether_multi 1 0K 0K 166960K 3 0 ISOFS mount 1 32K 32K 166960K 1 0 MSDOSFS mount 1 16K 16K 166960K 1 0 ttys 79 360K 360K 166960K 79 0 exec 0 0K 1K 166960K 370 0 fusefs mount 1 32K 32K 166960K 1 0 tdb 3 0K 0K 166960K 3 0 VM swap 8 62K 64K 166960K 10 0 UVM amap 215 65K 76K 166960K 3860 0 UVM aobj 7 2K 4K 166960K 10 0 pinsyscall 42 84K 117K 166960K 1317 0 memdesc 1 4K 4K 166960K 1 0 crypto data 1 1K 1K 166960K 1 0 ip6_options 0 0K 0K 166960K 7 0 NDP 10 0K 2K 166960K 27 0 temp 34 8634K 8698K 166960K 8392 0 kqueue 14 22K 30K 166960K 46 0 SYN cache 2 16K 16K 166960K 2 0 ddb{1}> show all pools Name Size Requests Fail Releases Pgreq Pgrel Npage Hiwat Minpg Maxpg Idle plcache 128 24 0 0 1 0 1 1 0 8 0 rtpcb 120 52 0 49 1 0 1 1 0 8 0 rtentry 112 114 0 12 4 0 4 4 0 8 0 unpcb 144 178 0 161 4 0 4 4 0 8 3 syncache 336 4 0 4 1 0 1 1 0 8 1 tcpcb 808 57 0 53 2 0 2 2 0 8 1 arp 120 18 0 2 1 0 1 1 0 8 0 ipq 40 2 0 1 1 0 1 1 0 8 0 ipqe 40 46 0 45 1 0 1 1 0 8 0 inpcb 376 173 0 159 3 0 3 3 0 8 1 nd6 136 27 0 3 1 0 1 1 0 8 0 kcovpl 48 12 0 5 1 0 1 1 0 8 0 art_heap8 4096 1 0 0 1 0 1 1 0 8 0 art_heap4 256 459 0 44 29 0 29 29 0 8 2 art_table 32 460 0 44 4 0 4 4 0 8 0 art_node 16 113 0 20 1 0 1 1 0 8 0 sysvmsgpl 40 4 0 4 1 0 1 1 0 8 1 semupl 112 4 0 4 1 0 1 1 0 8 1 semapl 112 4 0 0 1 0 1 1 0 8 0 shmpl 112 7 0 3 1 0 1 1 0 8 0 pool(0xffffffff83899b58:shmpl): page inconsistency: page 0xfffffd806b91e000; 30 on list, 4 missing, 35 items per page dirhash 1024 25 0 8 3 0 3 3 0 8 0 dino2pl 256 1736 0 228 95 0 95 95 0 8 0 ffsino 280 1736 0 228 109 0 109 109 0 8 0 nchpl 144 2071 0 393 63 0 63 63 0 8 0 uvmvnodes 80 1855 0 0 38 0 38 38 0 8 0 vnodes 216 1855 0 0 104 0 104 104 0 8 0 namei 1024 6289 0 6289 1 0 1 1 0 8 1 percpumem 16 46 0 1 1 0 1 1 0 8 0 kstatmem 264 22 0 2 2 0 2 2 0 8 0 scxspl 216 6612 0 6612 2 1 1 2 1 8 1 plimitpl 152 92 0 69 2 0 2 2 0 8 1 sigapl 424 554 0 502 8 0 8 8 0 8 1 futexpl 64 1699 0 1697 1 0 1 1 0 8 0 knotepl 120 315 0 0 10 0 10 10 0 8 0 kqueuepl 216 62 0 49 2 0 2 2 0 8 1 pipepl 328 130 0 103 3 0 3 3 0 8 0 fdescpl 504 535 0 502 7 1 6 6 0 8 1 filepl 152 2163 0 1957 12 0 12 12 0 8 3 lockfpl 104 61 0 59 1 0 1 1 0 8 0 lockfspl 48 23 0 21 1 0 1 1 0 8 0 sessionpl 144 26 0 11 1 0 1 1 0 8 0 pgrppl 48 39 0 16 1 0 1 1 0 8 0 ucredpl 104 258 0 240 1 0 1 1 0 8 0 zombiepl 144 502 0 502 1 0 1 1 0 8 1 processpl 1168 554 0 502 5 0 5 5 0 8 0 procpl 656 752 0 695 7 0 7 7 0 8 1 sosppl 168 3 0 3 1 0 1 1 0 8 1 sockpl 688 403 0 369 10 0 10 10 0 8 6 mcl64k 65536 5 0 0 1 0 1 1 0 8 0 mcl16k 16384 5 0 0 1 0 1 1 0 8 0 mcl12k 12288 2 0 0 1 0 1 1 0 8 0 mcl9k 9216 3 0 0 1 0 1 1 0 8 0 mcl8k 8192 7 0 0 1 0 1 1 0 8 0 mcl4k 4096 108 0 0 14 0 14 14 0 8 0 mcl2k 2048 21 0 0 3 0 3 3 0 8 0 mtagpl 96 1 0 0 1 0 1 1 0 8 0 mbufpl 256 336 0 0 21 0 21 21 0 8 0 bufpl 280 2417 0 123 164 0 164 164 0 8 0 anonpl 24 122246 0 117221 58 0 58 58 0 184 14 amapchunkpl 152 12018 0 11487 32 0 32 32 0 158 6 amappl16 200 2675 0 2606 17 0 17 17 0 8 9 amappl15 192 8 0 8 1 1 0 1 0 8 0 amappl14 184 106 0 96 1 0 1 1 0 8 0 amappl13 176 5 0 5 1 1 0 1 0 8 0 amappl12 168 1156 0 1123 2 0 2 2 0 8 0 amappl11 160 50 0 40 1 0 1 1 0 8 0 amappl10 152 36 0 36 1 1 0 1 0 8 0 amappl9 144 245 0 245 1 1 0 1 0 8 0 amappl8 136 53 0 51 1 0 1 1 0 8 0 amappl7 128 113 0 103 1 0 1 1 0 8 0 amappl6 120 176 0 172 1 0 1 1 0 8 0 amappl5 112 115 0 109 1 0 1 1 0 8 0 amappl4 104 288 0 271 1 0 1 1 0 8 0 amappl3 96 2046 0 1939 4 0 4 4 0 8 0 amappl2 88 640 0 585 2 0 2 2 0 8 0 amappl1 80 8197 0 7656 14 0 14 14 0 8 0 amappl 88 3496 0 3328 6 0 6 6 0 92 0 dma4096 4096 1 0 1 1 1 0 1 0 8 0 dma1024 1024 1 0 0 1 0 1 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 72 9 0 3 1 0 1 1 0 8 0 uaddrrnd 24 535 0 502 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 535 0 502 1 0 1 1 0 8 0 vmmpekpl 168 5959 0 5913 3 0 3 3 0 8 0 vmmpepl 168 40262 0 38406 103 0 103 103 0 357 9 vmsppl 456 534 0 502 7 1 6 6 0 8 1 rwobjpl 64 16322 0 13590 48 0 48 48 0 8 0 pdppl 4096 1077 0 1004 111 30 81 97 0 8 8 pvpl 32 17369 0 0 141 0 141 141 0 265 0 pmappl 248 534 0 502 4 1 3 3 0 8 0 extentpl 40 55 0 38 1 0 1 1 0 8 0 phpool 112 299 0 33 8 0 8 8 0 8 0 ddb{1}> machine ddbcpu 0 Stopped at x86_ipi_db+0x27: addq $0x8,%rsp x86_ipi_db(ffffffff83858ff0) at x86_ipi_db+0x27 sys/arch/amd64/amd64/db_interface.c:393 x86_ipi_handler() at x86_ipi_handler+0xd9 sys/arch/amd64/amd64/ipi.c:106 Xresume_lapic_ipi() at Xresume_lapic_ipi+0x27 __mp_lock(ffffffff838e8428) at __mp_lock+0x199 __mp_lock_spin sys/kern/kern_lock.c:113 [inline] __mp_lock(ffffffff838e8428) at __mp_lock+0x199 sys/kern/kern_lock.c:144 softintr_dispatch(0) at softintr_dispatch+0x5b sys/arch/amd64/amd64/softintr.c:88 Xsoftclock() at Xsoftclock+0x27 end of kernel end trace frame: 0x76b0759f7290, count: 9 ddb{0}> trace x86_ipi_db(ffffffff83858ff0) at x86_ipi_db+0x27 sys/arch/amd64/amd64/db_interface.c:393 x86_ipi_handler() at x86_ipi_handler+0xd9 sys/arch/amd64/amd64/ipi.c:106 Xresume_lapic_ipi() at Xresume_lapic_ipi+0x27 __mp_lock(ffffffff838e8428) at __mp_lock+0x199 __mp_lock_spin sys/kern/kern_lock.c:113 [inline] __mp_lock(ffffffff838e8428) at __mp_lock+0x199 sys/kern/kern_lock.c:144 softintr_dispatch(0) at softintr_dispatch+0x5b sys/arch/amd64/amd64/softintr.c:88 Xsoftclock() at Xsoftclock+0x27 end of kernel end trace frame: 0x76b0759f7290, count: -6 ddb{0}> machine ddbcpu 1 Stopped at db_enter+0x25: addq $0x8,%rsp db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:437 panic(ffffffff833a8df1) at panic+0x1e5 sys/kern/subr_prf.c:198 pool_do_get(ffffffff83899b58,1,ffff8000358cc468) at pool_do_get+0x5da pool_get(ffffffff83899b58,1) at pool_get+0x149 shmget_allocate_segment(ffff8000ffff4028,ffff8000358cc6c0,0,ffff8000358cc610) at shmget_allocate_segment+0x1a7 sys_shmget(ffff8000ffff4028,ffff8000358cc6c0,ffff8000358cc610) at sys_shmget+0x1b2 sys/kern/sysv_shm.c:482 syscall(ffff8000358cc6c0) at syscall+0xb08 mi_syscall sys/sys/syscall_mi.h:176 [inline] syscall(ffff8000358cc6c0) at syscall+0xb08 sys/arch/amd64/amd64/trap.c:577 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x77e8d1e5310, count: 7 ddb{1}> trace db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:437 panic(ffffffff833a8df1) at panic+0x1e5 sys/kern/subr_prf.c:198 pool_do_get(ffffffff83899b58,1,ffff8000358cc468) at pool_do_get+0x5da pool_get(ffffffff83899b58,1) at pool_get+0x149 shmget_allocate_segment(ffff8000ffff4028,ffff8000358cc6c0,0,ffff8000358cc610) at shmget_allocate_segment+0x1a7 sys_shmget(ffff8000ffff4028,ffff8000358cc6c0,ffff8000358cc610) at sys_shmget+0x1b2 sys/kern/sysv_shm.c:482 syscall(ffff8000358cc6c0) at syscall+0xb08 mi_syscall sys/sys/syscall_mi.h:176 [inline] syscall(ffff8000358cc6c0) at syscall+0xb08 sys/arch/amd64/amd64/trap.c:577 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x77e8d1e5310, count: -8