panic: pool_do_get: shmpl free list modified: page 0xfffffd806bdd8000; item addr 0xfffffd806bdd8a10; offset 0x40=0x67acece2 Stopped at db_enter+0x25: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND *520899 68656 32767 0x10 0x4000000 1K syz-executor 383720 7708 32767 0x10 0 0 syz-executor db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:437 panic(ffffffff833a6a27) at panic+0x1e5 sys/kern/subr_prf.c:198 pool_do_get(ffffffff83989de0,2,ffff80003c5223d8) at pool_do_get+0x5da pool_get(ffffffff83989de0,2) at pool_get+0x149 shmget_allocate_segment(ffff80003c554a70,ffff80003c522630,160,ffff80003c522580) at shmget_allocate_segment+0x1a7 sys_shmget(ffff80003c554a70,ffff80003c522630,ffff80003c522580) at sys_shmget+0x1b2 sys/kern/sysv_shm.c:482 syscall(ffff80003c522630) at syscall+0xb08 mi_syscall sys/sys/syscall_mi.h:176 [inline] syscall(ffff80003c522630) at syscall+0xb08 sys/arch/amd64/amd64/trap.c:577 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0xea7c1be66d0, 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 0xfffffd806bdd8000; item addr 0xfffffd806bdd8a10; offset 0x40=0x67acece2 ddb{1}> trace db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:437 panic(ffffffff833a6a27) at panic+0x1e5 sys/kern/subr_prf.c:198 pool_do_get(ffffffff83989de0,2,ffff80003c5223d8) at pool_do_get+0x5da pool_get(ffffffff83989de0,2) at pool_get+0x149 shmget_allocate_segment(ffff80003c554a70,ffff80003c522630,160,ffff80003c522580) at shmget_allocate_segment+0x1a7 sys_shmget(ffff80003c554a70,ffff80003c522630,ffff80003c522580) at sys_shmget+0x1b2 sys/kern/sysv_shm.c:482 syscall(ffff80003c522630) at syscall+0xb08 mi_syscall sys/sys/syscall_mi.h:176 [inline] syscall(ffff80003c522630) at syscall+0xb08 sys/arch/amd64/amd64/trap.c:577 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0xea7c1be66d0, count: -8 ddb{1}> show registers rdi 0 rsi 0x1 rbp 0xffff80003c522210 rbx 0xffff800029aacdc7 rdx 0xffff800001437c80 rcx 0xffff80003c554a70 rax 0xffff800029aabff0 r8 0x101010101010101 r9 0x8080808080808080 r10 0xc20029c8383a228d r11 0x604055696a2321ab r12 0xffff800029aacbc8 r13 0 r14 0 r15 0x1 rip 0xffffffff81809c75 db_enter+0x25 cs 0x8 rflags 0x246 rsp 0xffff80003c522200 ss 0x10 db_enter+0x25: addq $0x8,%rsp ddb{1}> show proc PROC (syz-executor) tid=520899 pid=68656 tcnt=2 stat=onproc flags process=10 proc=4000000 runpri=32, usrpri=50, slppri=32, nice=20 wchan=0x0, wmesg=, ps_single=0x0 scnt=0 ecnt=0 forw=0xffffffffffffffff, list=0xffff80003c555c60,0xffff80003c554fa0 process=0xffff80003c4fd4b0 user=0xffff80003c51d000, vmspace=0xfffffd806bfa31f8 estcpu=34, cpticks=2, pctcpu=0.0, user=0, sys=2, intr=0 ddb{1}> ps PID TID PPID UID S FLAGS WAIT COMMAND 24851 178404 45024 0 2 0 syz-executor 9150 34261 41048 32767 2 0x10 syz-executor 9150 190161 41048 32767 3 0x4000090 fsleep syz-executor 68656 47451 90547 32767 2 0x10 syz-executor *68656 520899 90547 32767 7 0x4000010 syz-executor 7708 383720 3483 32767 7 0x10 syz-executor 7708 478120 3483 32767 3 0x4000090 kqread syz-executor 86613 296625 84419 32767 2 0x10 syz-executor 86613 510642 84419 32767 3 0x4000090 fsleep syz-executor 86613 162075 84419 32767 3 0x4000090 fsleep syz-executor 45024 31929 33923 0 3 0x82 wait syz-executor 28162 312530 19907 32767 2 0x10 syz-executor 28162 135073 19907 32767 3 0x4000090 msgwait syz-executor 28162 264684 19907 32767 3 0x4000090 fsleep syz-executor 84419 152573 36809 32767 3 0x90 nanoslp syz-executor 36809 333280 33923 0 3 0x82 wait syz-executor 5210 520182 0 0 3 0x14200 bored sosplice 3483 314521 46166 32767 3 0x90 nanoslp syz-executor 90547 468945 43287 32767 3 0x90 nanoslp syz-executor 67213 99704 53587 32767 3 0x90 nanoslp syz-executor 41048 427355 52829 32767 3 0x90 nanoslp syz-executor 19907 89787 53074 32767 3 0x90 nanoslp syz-executor 43287 673 33923 0 3 0x82 wait syz-executor 46166 230346 33923 0 3 0x82 wait syz-executor 52829 88284 33923 0 3 0x82 wait syz-executor 53587 187904 33923 0 3 0x82 wait syz-executor 53074 404704 33923 0 3 0x82 wait syz-executor 33923 252386 91625 0 3 0x82 nanoslp syz-executor 91625 469114 59518 0 3 0x10008a sigsusp ksh 59518 347619 77994 0 3 0x98 kqread sshd-session 77994 331941 1312 0 3 0x92 kqread sshd-session 18936 11228 1 0 3 0x100083 ttyin getty 1312 227055 1 0 3 0x88 kqread sshd 23528 264726 89735 73 3 0x1100090 kqread syslogd 89735 82246 1 0 3 0x100082 sbwait syslogd 48239 147698 1 0 3 0x100080 kqread resolvd 20315 333373 95505 77 3 0x100092 kqread dhcpleased 65221 20008 95505 77 3 0x100092 kqread dhcpleased 95505 43841 1 0 3 0x80 kqread dhcpleased 83166 438018 0 0 3 0x14200 bored smr 93411 479201 0 0 2 0x14200 zerothread 84500 184357 0 0 3 0x14200 aiodoned aiodoned 94324 311244 0 0 3 0x14200 syncer update 45302 367125 0 0 3 0x14200 cleaner cleaner 63413 278712 0 0 3 0x14200 reaper reaper 12819 287776 0 0 3 0x14200 pgdaemon pagedaemon 73970 216218 0 0 3 0x14200 bored viomb 18850 209936 0 0 3 0x40014200 acpi0 acpi0 64828 374907 0 0 3 0x40014200 idle1 71754 55436 0 0 3 0x14200 bored softnet3 19022 450720 0 0 3 0x14200 bored softnet2 62891 257870 0 0 3 0x14200 bored softnet1 42244 310861 0 0 3 0x14200 bored softnet0 65643 371727 0 0 3 0x14200 bored systqmp 94673 101760 0 0 3 0x14200 bored systq 75112 491043 0 0 3 0x14200 tmoslp softclockmp 17587 147447 0 0 3 0x40014200 tmoslp softclock 79034 375694 0 0 3 0x40014200 idle0 1 68748 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 (0xffffffff83989df8) #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 68656 (syz-executor) thread 0xffff80003c554a70 (520899) exclusive kernel_lock &kernel_lock r = 0 (0xffffffff83983558) #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 (0xffffffff83989df8) #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 10185 10950K 10966K 166960K 11273 0 pcb 17 12K 12K 166960K 17 0 rtable 192 5K 6K 166960K 380 0 pf 27 16K 16K 166960K 33 0 ifaddr 34 6K 7K 166960K 48 0 ifgroup 42 1K 2K 166960K 54 0 sysctl 1 1K 1K 166960K 1 0 counters 60 35K 36K 166960K 66 0 ioctlops 0 0K 2K 166960K 32 0 iov 0 0K 12K 166960K 73 0 mount 1 1K 1K 166960K 1 0 log 0 0K 0K 166960K 4 0 vnodes 1332 84K 84K 166960K 1607 0 UFS quota 1 32K 32K 166960K 1 0 UFS mount 5 36K 36K 166960K 5 0 shm 2 1K 5K 166960K 6 0 VM map 2 1K 1K 166960K 2 0 sem 12 0K 0K 166960K 20 0 dirhash 12 2K 2K 166960K 15 0 ACPI 1692 195K 286K 166960K 12470 0 file desc 22 81K 125K 166960K 405 0 sigio 1 0K 0K 166960K 6 0 proc 59 91K 115K 166960K 528 0 subproc 63 3K 4K 166960K 324 0 NFS srvsock 1 0K 0K 166960K 1 0 NFS daemon 1 16K 16K 166960K 1 0 ip_moptions 0 0K 0K 166960K 26 0 in_multi 77 5K 7K 166960K 119 0 ether_multi 1 0K 0K 166960K 3 0 mrt 1 0K 0K 166960K 1 0 ISOFS mount 1 32K 32K 166960K 1 0 MSDOSFS mount 1 16K 16K 166960K 1 0 ttys 91 413K 413K 166960K 91 0 exec 0 0K 1K 166960K 400 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 225 57K 92K 166960K 4332 0 UVM aobj 8 3K 4K 166960K 10 0 pinsyscall 43 86K 114K 166960K 1448 0 memdesc 1 4K 4K 166960K 1 0 crypto data 1 1K 1K 166960K 1 0 ip6_options 0 0K 0K 166960K 44 0 NDP 11 0K 2K 166960K 30 0 temp 35 8635K 8700K 166960K 4911 0 kqueue 13 20K 30K 166960K 71 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 51 0 46 1 0 1 1 0 8 0 rtentry 112 123 0 34 4 0 4 4 0 8 0 unpcb 144 159 0 144 2 0 2 2 0 8 1 syncache 336 8 0 8 1 0 1 1 0 8 1 tcpqe 32 4 0 4 1 0 1 1 0 8 1 tcpcb 808 84 0 77 2 0 2 2 0 8 0 arp 120 21 0 6 1 0 1 1 0 8 0 ipq 40 1 0 0 1 0 1 1 0 8 0 ipqe 40 1 0 0 1 0 1 1 0 8 0 inpcb 376 326 0 315 8 0 8 8 0 8 5 nd6 136 27 0 9 1 0 1 1 0 8 0 kcovpl 48 36 0 29 1 0 1 1 0 8 0 art_heap8 4096 1 0 0 1 0 1 1 0 8 0 art_heap4 256 496 0 132 29 0 29 29 0 8 6 art_table 32 497 0 132 4 0 4 4 0 8 0 art_node 16 122 0 41 1 0 1 1 0 8 0 sysvmsgpl 40 1 0 0 1 0 1 1 0 8 0 semupl 112 1 0 1 1 0 1 1 0 8 1 semapl 112 18 0 8 1 0 1 1 0 8 0 shmpl 112 7 0 2 1 0 1 1 0 8 0 pool(0xffffffff83989de0:shmpl): page inconsistency: page 0xfffffd806bdd8000; 29 on list, 5 missing, 35 items per page dirhash 1024 19 0 2 3 0 3 3 0 8 0 dino2pl 256 1777 0 237 97 0 97 97 0 8 0 ffsino 280 1777 0 237 110 0 110 110 0 8 0 nchpl 144 2177 0 465 64 0 64 64 0 8 0 uvmvnodes 80 2110 0 0 44 0 44 44 0 8 0 vnodes 216 2110 0 0 118 0 118 118 0 8 0 namei 1024 6989 0 6989 2 0 2 2 0 8 2 percpumem 16 47 0 3 1 0 1 1 0 8 0 kstatmem 264 24 0 6 2 0 2 2 0 8 0 scxspl 216 7199 0 7199 9 1 8 8 1 8 8 plimitpl 152 114 0 93 2 0 2 2 0 8 1 sigapl 424 625 0 572 8 0 8 8 0 8 1 futexpl 64 2403 0 2399 1 0 1 1 0 8 0 knotepl 120 552 0 0 17 0 17 17 0 8 0 kqueuepl 216 75 0 65 1 0 1 1 0 8 0 pipepl 328 202 0 174 3 0 3 3 0 8 0 fdescpl 504 606 0 572 7 1 6 6 0 8 0 filepl 152 2746 0 2544 11 0 11 11 0 8 2 lockfpl 104 60 0 58 1 0 1 1 0 8 0 lockfspl 48 26 0 24 1 0 1 1 0 8 0 sessionpl 144 53 0 39 1 0 1 1 0 8 0 pgrppl 48 91 0 70 1 0 1 1 0 8 0 ucredpl 104 252 0 235 1 0 1 1 0 8 0 zombiepl 144 573 0 572 1 0 1 1 0 8 0 processpl 1168 625 0 572 5 0 5 5 0 8 0 procpl 656 846 0 786 7 0 7 7 0 8 0 sosppl 168 1 0 1 1 0 1 1 0 8 1 sockpl 688 538 0 508 9 0 9 9 0 8 4 mcl64k 65536 1 0 0 1 0 1 1 0 8 0 mcl8k 8192 2 0 0 1 0 1 1 0 8 0 mcl4k 4096 126 0 0 16 0 16 16 0 8 0 mcl2k 2048 19 0 0 3 0 3 3 0 8 0 mtagpl 96 5 0 0 1 0 1 1 0 8 0 mbufpl 256 165 0 0 11 0 11 11 0 8 0 bufpl 280 2501 0 124 170 0 170 170 0 8 0 anonpl 24 109660 0 106559 23 0 23 23 0 184 1 amapchunkpl 152 13664 0 13137 38 0 38 38 0 158 16 amappl16 200 1932 0 1912 5 2 3 5 0 8 1 amappl15 192 7 0 7 1 1 0 1 0 8 0 amappl14 184 110 0 100 1 0 1 1 0 8 0 amappl13 176 7 0 7 2 1 1 1 0 8 1 amappl12 168 1225 0 1192 2 0 2 2 0 8 0 amappl11 160 45 0 35 1 0 1 1 0 8 0 amappl10 152 4 0 4 1 1 0 1 0 8 0 amappl9 144 252 0 252 1 1 0 1 0 8 0 amappl8 136 25 0 23 1 0 1 1 0 8 0 amappl7 128 98 0 88 1 0 1 1 0 8 0 amappl6 120 181 0 178 1 0 1 1 0 8 0 amappl5 112 119 0 113 1 0 1 1 0 8 0 amappl4 104 294 0 280 1 0 1 1 0 8 0 amappl3 96 2309 0 2186 4 0 4 4 0 8 0 amappl2 88 666 0 611 2 0 2 2 0 8 0 amappl1 80 9401 0 8866 14 0 14 14 0 8 0 amappl 88 3930 0 3750 5 0 5 5 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 2 1 0 1 1 0 8 0 uaddrrnd 24 606 0 572 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 606 0 572 1 0 1 1 0 8 0 vmmpekpl 168 7364 0 7322 3 0 3 3 0 8 0 vmmpepl 168 44077 0 42198 97 0 97 97 0 357 15 vmsppl 456 605 0 572 7 1 6 6 0 8 0 rwobjpl 64 17280 0 14340 49 0 49 49 0 8 0 pdppl 4096 1220 0 1144 110 34 76 98 0 8 0 pvpl 32 11513 0 0 94 1 93 93 0 265 0 pmappl 248 605 0 572 4 1 3 3 0 8 0 extentpl 40 55 0 38 1 0 1 1 0 8 0 phpool 112 292 0 37 8 0 8 8 0 8 0 ddb{1}> machine ddbcpu 0 Stopped at x86_ipi_db+0x27: addq $0x8,%rsp x86_ipi_db(ffffffff837c2ff0) 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(ffffffff83983350) at __mp_lock+0x192 __mp_lock_spin sys/kern/kern_lock.c:113 [inline] __mp_lock(ffffffff83983350) at __mp_lock+0x192 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: 0x7805ed34b7e0, count: 9 ddb{0}> trace x86_ipi_db(ffffffff837c2ff0) 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(ffffffff83983350) at __mp_lock+0x192 __mp_lock_spin sys/kern/kern_lock.c:113 [inline] __mp_lock(ffffffff83983350) at __mp_lock+0x192 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: 0x7805ed34b7e0, 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(ffffffff833a6a27) at panic+0x1e5 sys/kern/subr_prf.c:198 pool_do_get(ffffffff83989de0,2,ffff80003c5223d8) at pool_do_get+0x5da pool_get(ffffffff83989de0,2) at pool_get+0x149 shmget_allocate_segment(ffff80003c554a70,ffff80003c522630,160,ffff80003c522580) at shmget_allocate_segment+0x1a7 sys_shmget(ffff80003c554a70,ffff80003c522630,ffff80003c522580) at sys_shmget+0x1b2 sys/kern/sysv_shm.c:482 syscall(ffff80003c522630) at syscall+0xb08 mi_syscall sys/sys/syscall_mi.h:176 [inline] syscall(ffff80003c522630) at syscall+0xb08 sys/arch/amd64/amd64/trap.c:577 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0xea7c1be66d0, count: 7 ddb{1}> trace db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:437 panic(ffffffff833a6a27) at panic+0x1e5 sys/kern/subr_prf.c:198 pool_do_get(ffffffff83989de0,2,ffff80003c5223d8) at pool_do_get+0x5da pool_get(ffffffff83989de0,2) at pool_get+0x149 shmget_allocate_segment(ffff80003c554a70,ffff80003c522630,160,ffff80003c522580) at shmget_allocate_segment+0x1a7 sys_shmget(ffff80003c554a70,ffff80003c522630,ffff80003c522580) at sys_shmget+0x1b2 sys/kern/sysv_shm.c:482 syscall(ffff80003c522630) at syscall+0xb08 mi_syscall sys/sys/syscall_mi.h:176 [inline] syscall(ffff80003c522630) at syscall+0xb08 sys/arch/amd64/amd64/trap.c:577 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0xea7c1be66d0, count: -8