panic: pool_do_get: shmpl free list modified: page 0xfffffd806ce03000; item addr 0xfffffd806ce038c0; offset 0x40=0x695bef2c Stopped at db_enter+0x25: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND 5172 61288 32767 0x10 0 0 syz-executor * 75349 61288 32767 0x10 0x4000000 1K syz-executor db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:438 panic(ffffffff833a3708) at panic+0x1e5 sys/kern/subr_prf.c:198 pool_do_get(ffffffff839ff368,1,ffff80002a2f3e98) at pool_do_get+0x5df pool_get(ffffffff839ff368,1) at pool_get+0x162 sys/kern/subr_pool.c:-1 shmget_allocate_segment(ffff800033fe3cb0,ffff80002a2f40f0,5d,ffff80002a2f4040) at shmget_allocate_segment+0x1af sys/kern/sysv_shm.c:-1 sys_shmget(ffff800033fe3cb0,ffff80002a2f40f0,ffff80002a2f4040) at sys_shmget+0x195 sys/kern/sysv_shm.c:482 syscall(ffff80002a2f40f0) at syscall+0xb17 mi_syscall sys/sys/syscall_mi.h:176 [inline] syscall(ffff80002a2f40f0) at syscall+0xb17 sys/arch/amd64/amd64/trap.c:775 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x91459d09440, 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 0xfffffd806ce03000; item addr 0xfffffd806ce038c0; offset 0x40=0x695bef2c ddb{1}> trace db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:438 panic(ffffffff833a3708) at panic+0x1e5 sys/kern/subr_prf.c:198 pool_do_get(ffffffff839ff368,1,ffff80002a2f3e98) at pool_do_get+0x5df pool_get(ffffffff839ff368,1) at pool_get+0x162 sys/kern/subr_pool.c:-1 shmget_allocate_segment(ffff800033fe3cb0,ffff80002a2f40f0,5d,ffff80002a2f4040) at shmget_allocate_segment+0x1af sys/kern/sysv_shm.c:-1 sys_shmget(ffff800033fe3cb0,ffff80002a2f40f0,ffff80002a2f4040) at sys_shmget+0x195 sys/kern/sysv_shm.c:482 syscall(ffff80002a2f40f0) at syscall+0xb17 mi_syscall sys/sys/syscall_mi.h:176 [inline] syscall(ffff80002a2f40f0) at syscall+0xb17 sys/arch/amd64/amd64/trap.c:775 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x91459d09440, count: -8 ddb{1}> show registers rdi 0 rsi 0x1 rbp 0xffff80002a2f3cc0 rbx 0xffff8000299dee07 rdx 0xffff8000015801c0 rcx 0xffff800033fe3cb0 rax 0xffff8000299ddff0 r8 0x101010101010101 r9 0x8080808080808080 r10 0xc477b93462e5270a r11 0xc6a3c264a73ad5d7 r12 0xffff8000299dec08 r13 0 r14 0 r15 0x1 rip 0xffffffff817d67d5 db_enter+0x25 cs 0x8 rflags 0x246 rsp 0xffff80002a2f3cb0 ss 0x10 db_enter+0x25: addq $0x8,%rsp ddb{1}> show proc PROC (syz-executor) tid=75349 pid=61288 tcnt=3 stat=onproc flags process=10 proc=4000000 runpri=32, usrpri=79, slppri=32, nice=20 wchan=0x0, wmesg=, ps_single=0x0 scnt=0 ecnt=0 forw=0xffffffffffffffff, list=0xffff800033fe2a88,0xffff800033fe2d30 process=0xffff80003a806b70 user=0xffff80002a2ef000, vmspace=0xfffffd806cc1db90 estcpu=29, cpticks=3, pctcpu=0.0, user=0, sys=3, intr=0 ddb{1}> ps PID TID PPID UID S FLAGS WAIT COMMAND 61288 5172 91948 32767 7 0x10 syz-executor *61288 75349 91948 32767 7 0x4000010 syz-executor 61288 150154 91948 32767 3 0x4000090 fsleep syz-executor 41146 105154 92989 32767 3 0x90 nanoslp syz-executor 41146 437423 92989 32767 3 0x4000090 kqsel syz-executor 41146 125860 92989 32767 3 0x4000090 fsleep syz-executor 21800 410935 14530 32767 3 0x90 nanoslp syz-executor 21800 379932 14530 32767 3 0x4000090 msgwait syz-executor 21800 451780 14530 32767 3 0x4000090 fsleep syz-executor 54037 221783 74064 0 3 0x100082 sbwait ndp 74064 214560 45827 0 3 0x10008a sigsusp sh 61631 14014 7594 32767 3 0x90 piperd syz-executor 91948 31099 69721 32767 3 0x90 nanoslp syz-executor 14530 458727 27753 32767 3 0x90 nanoslp syz-executor 70948 94040 8581 32767 3 0x90 piperd syz-executor 92989 503783 66660 32767 3 0x90 nanoslp syz-executor 28085 504686 68012 32767 3 0x90 piperd syz-executor 45827 455927 96479 0 3 0x80 wait syz-executor 27753 270128 18446 0 3 0x82 wait syz-executor 7594 470848 18446 0 3 0x82 wait syz-executor 69721 42986 18446 0 3 0x82 wait syz-executor 8581 254540 18446 0 3 0x82 wait syz-executor 66660 418181 18446 0 3 0x82 wait syz-executor 96479 266817 18446 0 3 0x82 wait syz-executor 68012 417164 18446 0 3 0x82 wait syz-executor 18446 270515 14540 0 3 0x82 nanoslp syz-executor 14540 276151 6026 0 3 0x10008a sigsusp ksh 6026 22736 9355 0 3 0x98 kqread sshd-session 9355 486642 74116 0 3 0x92 kqread sshd-session 72308 480839 1 0 3 0x100083 ttyin getty 74116 108579 1 0 3 0x88 kqread sshd 43273 137300 90944 73 3 0x1100090 kqread syslogd 90944 468970 1 0 3 0x100082 sbwait syslogd 51126 431808 1 0 3 0x100080 kqread resolvd 51067 167378 82896 77 3 0x100092 kqread dhcpleased 8171 455633 82896 77 3 0x100092 kqread dhcpleased 82896 327965 1 0 3 0x80 kqread dhcpleased 9815 480204 0 0 3 0x14200 bored smr 31903 147853 0 0 3 0x14200 pgzero zerothread 3350 393970 0 0 3 0x14200 aiodoned aiodoned 39908 314075 0 0 3 0x14200 syncer update 60395 481228 0 0 3 0x14200 cleaner cleaner 78143 153452 0 0 3 0x14200 reaper reaper 38827 192265 0 0 3 0x14200 pgdaemon pagedaemon 36328 512591 0 0 3 0x14200 bored viomb 41380 422181 0 0 3 0x40014200 acpi0 acpi0 83857 455878 0 0 3 0x40014200 idle1 35304 431371 0 0 3 0x14200 bored softnet1 90131 153767 0 0 2 0x14200 softnet0 14130 146615 0 0 3 0x14200 bored systqmp 42379 482945 0 0 3 0x14200 bored systq 61927 235804 0 0 3 0x14200 tmoslp softclockmp 36809 51894 0 0 3 0x40014200 tmoslp softclock 82014 317840 0 0 3 0x40014200 idle0 1 397765 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 (0xffffffff839ff380) #0 witness_lock+0x5f1 stacktrace_save sys/sys/stacktrace.h:37 [inline] #0 witness_lock+0x5f1 sys/kern/subr_witness.c:1160 #1 mtx_enter+0x4b4 sys/kern/kern_lock.c:487 #2 pool_get+0x124 sys/kern/subr_pool.c:581 #3 shmget_allocate_segment+0x1af sys/kern/sysv_shm.c:-1 #4 sys_shmget+0x195 sys/kern/sysv_shm.c:482 #5 syscall+0xb17 mi_syscall sys/sys/syscall_mi.h:176 [inline] #5 syscall+0xb17 sys/arch/amd64/amd64/trap.c:775 #6 Xsyscall+0x128 Process 61288 (syz-executor) thread 0xffff800033fe3cb0 (75349) exclusive kernel_lock &kernel_lock r = 0 (0xffffffff83a03bc8) #0 witness_lock+0x5f1 stacktrace_save sys/sys/stacktrace.h:37 [inline] #0 witness_lock+0x5f1 sys/kern/subr_witness.c:1160 #1 syscall+0xaf4 mi_syscall sys/sys/syscall_mi.h:175 [inline] #1 syscall+0xaf4 sys/arch/amd64/amd64/trap.c:775 #2 Xsyscall+0x128 exclusive mutex shmpl r = 0 (0xffffffff839ff380) #0 witness_lock+0x5f1 stacktrace_save sys/sys/stacktrace.h:37 [inline] #0 witness_lock+0x5f1 sys/kern/subr_witness.c:1160 #1 mtx_enter+0x4b4 sys/kern/kern_lock.c:487 #2 pool_get+0x124 sys/kern/subr_pool.c:581 #3 shmget_allocate_segment+0x1af sys/kern/sysv_shm.c:-1 #4 sys_shmget+0x195 sys/kern/sysv_shm.c:482 #5 syscall+0xb17 mi_syscall sys/sys/syscall_mi.h:176 [inline] #5 syscall+0xb17 sys/arch/amd64/amd64/trap.c:775 #6 Xsyscall+0x128 ddb{1}> show malloc Type InUse MemUse HighUse Limit Requests Type Lim devbuf 11050 12016K 12034K 166960K 12144 0 pcb 17 12K 12K 166960K 17 0 rtable 217 6K 7K 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 1 1K 9K 166960K 7 0 counters 68 36K 37K 166960K 70 0 ioctlops 0 0K 2K 166960K 32 0 iov 0 0K 12K 166960K 6 0 mount 1 1K 1K 166960K 1 0 log 0 0K 0K 166960K 4 0 vnodes 1335 84K 84K 166960K 1512 0 UFS quota 1 32K 32K 166960K 1 0 UFS mount 5 36K 36K 166960K 5 0 shm 2 1K 5K 166960K 5 0 VM map 2 1K 1K 166960K 2 0 sem 8 0K 0K 166960K 9 0 dirhash 12 2K 2K 166960K 18 0 ACPI 1692 195K 286K 166960K 12470 0 file desc 21 77K 125K 166960K 308 0 sigio 0 0K 0K 166960K 7 0 proc 58 99K 163K 166960K 493 0 subproc 63 3K 4K 166960K 189 0 NFS srvsock 1 0K 0K 166960K 1 0 NFS daemon 1 16K 16K 166960K 1 0 ip_moptions 0 0K 0K 166960K 22 0 in_multi 88 6K 7K 166960K 105 0 ether_multi 1 0K 0K 166960K 1 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 435 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 230 169K 187K 166960K 4200 0 UVM aobj 10 2K 3K 166960K 11 0 pinsyscall 43 86K 114K 166960K 1356 0 memdesc 1 4K 4K 166960K 1 0 crypto data 1 1K 1K 166960K 1 0 ip6_options 2 0K 0K 166960K 19 0 NDP 10 0K 2K 166960K 27 0 temp 35 8667K 8731K 166960K 4500 0 kqueue 13 20K 24K 166960K 42 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 26 0 0 1 0 1 1 0 8 0 rtpcb 120 43 0 39 1 0 1 1 0 8 0 rtentry 176 113 0 13 6 0 6 6 0 8 1 unpcb 144 102 0 87 1 0 1 1 0 8 0 syncache 336 6 0 6 1 0 1 1 0 8 1 tcpqe 32 3 0 3 1 0 1 1 0 8 1 tcpcb 736 54 0 47 2 1 1 2 0 8 0 arp 136 18 0 2 1 0 1 1 0 8 0 ipq 40 1 0 0 1 0 1 1 0 8 0 ipqe 40 2 0 1 1 0 1 1 0 8 0 inpcb 328 173 0 162 2 0 2 2 0 8 0 ip6q 72 1 0 1 1 0 1 1 0 8 1 ip6af 40 2 0 2 1 0 1 1 0 8 1 nd6 152 26 0 4 1 0 1 1 0 8 0 kcovpl 48 21 0 14 1 0 1 1 0 8 0 art_heap8 4096 1 0 0 1 0 1 1 0 8 0 art_heap4 256 456 0 46 29 2 27 29 0 8 0 art_table 40 457 0 46 5 0 5 5 0 8 0 art_node 32 113 0 22 1 0 1 1 0 8 0 semupl 112 1 0 1 1 0 1 1 0 8 1 semapl 112 7 0 1 1 0 1 1 0 8 0 shmpl 112 8 0 1 1 0 1 1 0 8 0 pool(0xffffffff839ff368:shmpl): page inconsistency: page 0xfffffd806ce03000; 27 on list, 7 missing, 35 items per page dirhash 1024 21 0 4 3 0 3 3 0 8 0 dino2pl 256 1767 0 246 96 0 96 96 0 8 0 ffsino 296 1767 0 246 118 0 118 118 0 8 0 nchpl 144 2109 0 414 64 0 64 64 0 8 0 vnodes 216 1965 0 0 110 0 110 110 0 8 0 namei 1024 6393 0 6393 1 0 1 1 0 8 1 percpumem 16 50 0 1 1 0 1 1 0 8 0 kstatmem 264 24 0 2 2 0 2 2 0 8 0 scxspl 216 6746 0 6746 3 2 1 2 1 8 1 plimitpl 152 85 0 62 2 0 2 2 0 8 1 sigapl 424 564 0 515 7 0 7 7 0 8 0 knotepl 120 318 0 0 10 0 10 10 0 8 0 kqueuepl 224 54 0 44 1 0 1 1 0 8 0 pipepl 344 173 0 145 3 0 3 3 0 8 0 fdescpl 528 548 0 515 4 0 4 4 0 8 0 filepl 160 2354 0 2149 11 1 10 11 0 8 0 lockfpl 104 38 0 36 1 0 1 1 0 8 0 lockfspl 48 17 0 15 1 0 1 1 0 8 0 sessionpl 144 36 0 21 1 0 1 1 0 8 0 pgrppl 48 59 0 37 1 0 1 1 0 8 0 ucredpl 104 369 0 352 1 0 1 1 0 8 0 zombiepl 144 515 0 515 1 0 1 1 0 8 1 processpl 1232 564 0 515 5 0 5 5 0 8 0 procpl 664 778 0 723 6 0 6 6 0 8 0 sockpl 752 320 0 290 5 1 4 5 0 8 0 mcl64k 65536 3 0 0 1 0 1 1 0 8 0 mcl8k 8192 2 0 0 1 0 1 1 0 8 0 mcl4k 4096 122 0 0 16 0 16 16 0 8 0 mcl2k2 2112 1 0 0 1 0 1 1 0 8 0 mcl2k 2048 31 0 0 5 1 4 5 0 8 0 mtagpl 96 2 0 0 1 0 1 1 0 8 0 mbufpl 256 1208 0 0 76 0 76 76 0 8 0 bufpl 280 2392 0 119 163 0 163 163 0 8 0 anonpl 32 8879 0 0 72 0 72 72 0 246 0 amapchunkpl 152 12607 0 12178 25 1 24 25 0 158 3 amappl16 200 2394 0 2375 15 5 10 13 0 8 8 amappl15 192 34 0 34 1 1 0 1 0 8 0 amappl14 184 14 0 14 2 2 0 1 0 8 0 amappl13 176 399 0 397 1 0 1 1 0 8 0 amappl12 168 878 0 836 3 0 3 3 0 8 0 amappl11 160 6 0 6 1 1 0 1 0 8 0 amappl10 152 45 0 35 1 0 1 1 0 8 0 amappl9 144 297 0 297 1 1 0 1 0 8 0 amappl8 136 17 0 16 1 0 1 1 0 8 0 amappl7 128 87 0 86 1 0 1 1 0 8 0 amappl6 120 301 0 288 1 0 1 1 0 8 0 amappl5 112 97 0 90 1 0 1 1 0 8 0 amappl4 104 372 0 345 1 0 1 1 0 8 0 amappl3 96 1937 0 1860 3 0 3 3 0 8 0 amappl2 88 677 0 604 2 0 2 2 0 8 0 amappl1 80 9913 0 9355 14 0 14 14 0 8 0 amappl 88 3480 0 3328 5 0 5 5 0 92 0 uvmvnodes 80 97 0 0 2 0 2 2 0 8 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 10 0 1 1 0 1 1 0 8 0 uaddrrnd 24 548 0 515 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 548 0 515 1 0 1 1 0 8 0 vmmpekpl 168 6383 0 6335 3 0 3 3 0 8 0 vmmpepl 168 43558 0 41717 98 3 95 98 0 357 5 vmsppl 488 547 0 515 7 1 6 6 0 8 0 rwobjpl 80 15355 0 14432 25 0 25 25 0 8 1 pdppl 4096 1103 0 1030 115 34 81 97 0 8 8 pvpl 32 17582 0 0 142 0 142 142 0 265 0 pmappl 256 547 0 515 4 1 3 3 0 8 0 extentpl 40 45 0 27 1 0 1 1 0 8 0 phpool 112 354 0 41 10 0 10 10 0 8 0 ddb{1}> machine ddbcpu 0 Stopped at x86_ipi_db+0x27: addq $0x8,%rsp x86_ipi_db(ffffffff83842ff0) at x86_ipi_db+0x27 sys/arch/amd64/amd64/db_interface.c:394 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(ffffffff83a039c0) at __mp_lock+0x199 __mp_lock_spin sys/kern/kern_lock.c:142 [inline] __mp_lock(ffffffff83a039c0) at __mp_lock+0x199 sys/kern/kern_lock.c:173 softintr_dispatch(0) at softintr_dispatch+0x125 sys/kern/kern_softintr.c:83 dosoftint(0) at dosoftint+0x54 sys/arch/amd64/amd64/intr.c:862 Xsoftclock() at Xsoftclock+0x27 end of kernel end trace frame: 0x7574551dacf0, count: 8 ddb{0}> trace x86_ipi_db(ffffffff83842ff0) at x86_ipi_db+0x27 sys/arch/amd64/amd64/db_interface.c:394 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(ffffffff83a039c0) at __mp_lock+0x199 __mp_lock_spin sys/kern/kern_lock.c:142 [inline] __mp_lock(ffffffff83a039c0) at __mp_lock+0x199 sys/kern/kern_lock.c:173 softintr_dispatch(0) at softintr_dispatch+0x125 sys/kern/kern_softintr.c:83 dosoftint(0) at dosoftint+0x54 sys/arch/amd64/amd64/intr.c:862 Xsoftclock() at Xsoftclock+0x27 end of kernel end trace frame: 0x7574551dacf0, count: -7 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:438 panic(ffffffff833a3708) at panic+0x1e5 sys/kern/subr_prf.c:198 pool_do_get(ffffffff839ff368,1,ffff80002a2f3e98) at pool_do_get+0x5df pool_get(ffffffff839ff368,1) at pool_get+0x162 sys/kern/subr_pool.c:-1 shmget_allocate_segment(ffff800033fe3cb0,ffff80002a2f40f0,5d,ffff80002a2f4040) at shmget_allocate_segment+0x1af sys/kern/sysv_shm.c:-1 sys_shmget(ffff800033fe3cb0,ffff80002a2f40f0,ffff80002a2f4040) at sys_shmget+0x195 sys/kern/sysv_shm.c:482 syscall(ffff80002a2f40f0) at syscall+0xb17 mi_syscall sys/sys/syscall_mi.h:176 [inline] syscall(ffff80002a2f40f0) at syscall+0xb17 sys/arch/amd64/amd64/trap.c:775 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x91459d09440, count: 7 ddb{1}> trace db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:438 panic(ffffffff833a3708) at panic+0x1e5 sys/kern/subr_prf.c:198 pool_do_get(ffffffff839ff368,1,ffff80002a2f3e98) at pool_do_get+0x5df pool_get(ffffffff839ff368,1) at pool_get+0x162 sys/kern/subr_pool.c:-1 shmget_allocate_segment(ffff800033fe3cb0,ffff80002a2f40f0,5d,ffff80002a2f4040) at shmget_allocate_segment+0x1af sys/kern/sysv_shm.c:-1 sys_shmget(ffff800033fe3cb0,ffff80002a2f40f0,ffff80002a2f4040) at sys_shmget+0x195 sys/kern/sysv_shm.c:482 syscall(ffff80002a2f40f0) at syscall+0xb17 mi_syscall sys/sys/syscall_mi.h:176 [inline] syscall(ffff80002a2f40f0) at syscall+0xb17 sys/arch/amd64/amd64/trap.c:775 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x91459d09440, count: -8