panic: pool_do_get: shmpl free list modified: page 0xfffffd80691fe000; item addr 0xfffffd80691fe240; offset 0x40=0x85a Stopped at db_enter+0x25: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND *252094 96690 0 0 0x4000000 0 syz-executor db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:438 panic(ffffffff83407964) at panic+0x1cf sys/kern/subr_prf.c:198 pool_do_get(ffffffff83a09b70,1,ffff8000384ecdb8) at pool_do_get+0x5bc pool_get(ffffffff83a09b70,1) at pool_get+0x11a sys/kern/subr_pool.c:-1 shmget_allocate_segment(ffff800038cfa560,ffff8000384ed000,5d,ffff8000384ecf50) at shmget_allocate_segment+0x1af sys/kern/sysv_shm.c:-1 sys_shmget(ffff800038cfa560,ffff8000384ed000,ffff8000384ecf50) at sys_shmget+0x195 sys/kern/sysv_shm.c:482 syscall(ffff8000384ed000) at syscall+0x962 mi_syscall sys/sys/syscall_mi.h:-1 [inline] syscall(ffff8000384ed000) at syscall+0x962 sys/arch/amd64/amd64/trap.c:783 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x3dc85378b60, 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> ddb> set $lines = 0 ddb> set $maxwidth = 0 ddb> show panic *cpu0: pool_do_get: shmpl free list modified: page 0xfffffd80691fe000; item addr 0xfffffd80691fe240; offset 0x40=0x85a ddb> trace db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:438 panic(ffffffff83407964) at panic+0x1cf sys/kern/subr_prf.c:198 pool_do_get(ffffffff83a09b70,1,ffff8000384ecdb8) at pool_do_get+0x5bc pool_get(ffffffff83a09b70,1) at pool_get+0x11a sys/kern/subr_pool.c:-1 shmget_allocate_segment(ffff800038cfa560,ffff8000384ed000,5d,ffff8000384ecf50) at shmget_allocate_segment+0x1af sys/kern/sysv_shm.c:-1 sys_shmget(ffff800038cfa560,ffff8000384ed000,ffff8000384ecf50) at sys_shmget+0x195 sys/kern/sysv_shm.c:482 syscall(ffff8000384ed000) at syscall+0x962 mi_syscall sys/sys/syscall_mi.h:-1 [inline] syscall(ffff8000384ed000) at syscall+0x962 sys/arch/amd64/amd64/trap.c:783 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x3dc85378b60, count: -8 ddb> show registers rdi 0 rsi 0x1 rbp 0xffff8000384ecc20 rbx 0xfffffd80691fe240 rdx 0xffff8000015e76c0 rcx 0 rax 0xffff800038cfa560 r8 0x101010101010101 r9 0x8080808080808080 r10 0x15e222f43adedd83 r11 0x81f076e27d91772e r12 0 r13 0xffffffff83a09b70 shm_pool r14 0 r15 0x1 rip 0xffffffff8330ea15 db_enter+0x25 cs 0x8 rflags 0x246 rsp 0xffff8000384ecc10 ss 0x10 db_enter+0x25: addq $0x8,%rsp ddb> show proc PROC (syz-executor) tid=252094 pid=96690 tcnt=2 stat=onproc flags process=0 proc=4000000 runpri=50, usrpri=50, slppri=17, nice=20 wchan=0x0, wmesg=, ps_single=0x0 scnt=0 ecnt=0 forw=0xffffffffffffffff, list=0xffff800038cfbcb8,0xffffffff839f6ee8 process=0xffff80003c946420 user=0xffff8000384e8000, vmspace=0xfffffd800e0ff468 estcpu=36, cpticks=1, pctcpu=0.0, user=0, sys=1, intr=0 ddb> ps PID TID PPID UID S FLAGS WAIT COMMAND 96690 124174 28052 0 3 0x80 fsleep syz-executor *96690 252094 28052 0 7 0x4000000 syz-executor 17923 245639 99009 0 3 0x80 fsleep syz-executor 17923 324894 99009 0 3 0x4000080 kqread syz-executor 99760 6219 13991 0 3 0x80 fsleep syz-executor 99760 280973 13991 0 2 0x4000000 syz-executor 77386 523321 48064 0 3 0x80 fsleep syz-executor 77386 41578 48064 0 3 0x4000080 piperd syz-executor 74615 21062 26240 0 3 0x80 fsleep syz-executor 74615 415176 26240 0 3 0x4000080 kqread syz-executor 17505 324995 1477 0 3 0x80 fsleep syz-executor 17505 15196 1477 0 3 0x4000080 kqread syz-executor 28710 411249 64864 0 3 0x80 fsleep syz-executor 28710 371987 64864 0 3 0x4000080 kqsel syz-executor 11727 209390 97419 0 3 0x80 fsleep syz-executor 11727 272122 97419 0 3 0x4000080 sbwait syz-executor 48064 267126 2804 0 3 0x82 nanoslp syz-executor 4300 264406 1 0 3 0x100083 ttyopn getty 97419 484767 2804 0 2 0xc82 syz-executor 13991 357405 2804 0 3 0x82 nanoslp syz-executor 1477 4395 2804 0 3 0x82 nanoslp syz-executor 28052 311384 2804 0 3 0x82 nanoslp syz-executor 99009 191401 2804 0 3 0x82 nanoslp syz-executor 64864 216447 2804 0 2 0xc82 syz-executor 26240 83824 2804 0 2 0xc82 syz-executor 2804 250575 68517 0 3 0x82 kqread syz-executor 68517 375047 47722 0 3 0x10008a sigsusp ksh 47722 438852 52624 0 3 0x98 kqread sshd-session 52624 515386 60035 0 3 0x92 kqread sshd-session 60035 154074 1 0 3 0x88 kqread sshd 11765 365089 18902 73 3 0x1100090 kqread syslogd 18902 110242 1 0 3 0x100082 sbwait syslogd 94630 451133 1 0 3 0x100080 kqread resolvd 77071 140419 29974 77 3 0x100092 kqread dhcpleased 33751 497600 29974 77 3 0x100092 kqread dhcpleased 29974 267740 1 0 3 0x80 kqread dhcpleased 53086 174111 0 0 3 0x14200 bored smr 73286 70148 0 0 2 0x14200 zerothread 40469 39392 0 0 3 0x14200 aiodoned aiodoned 46484 432284 0 0 3 0x14200 syncer update 55326 351359 0 0 3 0x14200 cleaner cleaner 40810 410266 0 0 3 0x14200 reaper reaper 84529 112895 0 0 3 0x14200 pgdaemon pagedaemon 56862 426414 0 0 3 0x14200 bored viomb 59750 132987 0 0 3 0x40014200 acpi0 acpi0 4565 39449 0 0 3 0x14200 bored softnet0 80603 141725 0 0 3 0x14200 bored systqmp 77714 175648 0 0 3 0x14200 bored systq 28519 319435 0 0 3 0x40014200 tmoslp softclock 63867 319196 0 0 3 0x40014200 idle0 1 161261 0 0 3 0x80082 wait init 0 0 -1 0 3 0x10010200 scheduler swapper ddb> show all locks No such command ddb> show malloc Type InUse MemUse HighUse Limit Requests Type Lim devbuf 11081 12131K 12554K 166960K 16422 0 pcb 17 20K 23K 166960K 1159 0 rtable 238 19K 20K 166960K 1009 0 pf 37 14K 16K 166960K 302 0 ifaddr 34 6K 8K 166960K 167 0 ifgroup 55 2K 2K 166960K 284 0 sysctl 4 1K 9K 166960K 35 0 counters 35 18K 18K 166960K 193 0 ioctlops 0 0K 4K 166960K 824 0 iov 0 0K 48K 166960K 147 0 mount 1 1K 1K 166960K 1 0 log 0 0K 0K 166960K 4 0 vnodes 1414 89K 90K 166960K 4374 0 UFS quota 1 32K 32K 166960K 1 0 UFS mount 5 36K 36K 166960K 5 0 shm 2 1K 5K 166960K 51 0 VM map 2 1K 1K 166960K 2 0 sem 12 0K 1K 166960K 288 0 dirhash 12 2K 2K 166960K 48 0 ACPI 1692 195K 286K 166960K 12470 0 file desc 18 65K 240K 166960K 3074 0 sigio 0 0K 0K 166960K 143 0 proc 60 59K 116K 166960K 905 0 subproc 72 4K 4K 166960K 129 0 NFS srvsock 1 0K 0K 166960K 1 0 NFS daemon 1 16K 16K 166960K 1 0 ip_moptions 0 0K 0K 166960K 633 0 in_multi 62 4K 7K 166960K 243 0 ether_multi 1 0K 0K 166960K 23 0 mrt 1 0K 0K 166960K 45 0 ISOFS mount 1 32K 32K 166960K 1 0 MSDOSFS mount 1 16K 16K 166960K 1 0 ttys 247 1102K 1102K 166960K 247 0 exec 0 0K 1K 166960K 809 0 fusefs mount 1 32K 32K 166960K 1 0 pfkey data 0 0K 0K 166960K 3 0 tdb 3 0K 0K 166960K 3 0 VM swap 8 62K 64K 166960K 10 0 UVM amap 220 135K 163K 166960K 27616 0 UVM aobj 98 26K 26K 166960K 111 0 pinsyscall 39 78K 96K 166960K 4333 0 memdesc 1 4K 4K 166960K 1 0 crypto data 1 1K 1K 166960K 1 0 ip6_options 0 0K 1K 166960K 231 0 NDP 13 0K 2K 166960K 127 0 temp 87 9076K 9158K 166960K 77717 0 kqueue 16 26K 33K 166960K 548 0 SYN cache 2 16K 16K 166960K 2 0 ddb> show all pools Name Size Requests Fail Releases Pgreq Pgrel Npage Hiwat Minpg Maxpg Idle rtpcb 120 304 0 301 2 0 2 2 0 8 1 rtentry 136 243 0 157 5 0 5 5 0 8 0 unpcb 144 2427 0 2410 13 9 4 7 0 8 3 syncache 336 13 0 13 3 2 1 1 0 8 1 tcpqe 32 14 0 14 2 2 0 1 0 8 0 tcpcb 736 1183 0 1175 25 16 9 13 0 8 7 arp 96 35 0 20 1 0 1 1 0 8 0 ipq 40 30 0 29 1 0 1 1 0 8 0 ipqe 40 64 0 63 1 0 1 1 0 8 0 inpcb 328 3972 0 3961 32 23 9 13 0 8 7 ip6q 72 7 0 5 1 0 1 1 0 8 0 ip6af 40 12 0 11 1 0 1 1 0 8 0 nd6 112 78 0 46 2 0 2 2 0 8 0 pkpcb 40 19 0 19 3 2 1 1 0 8 1 kcovpl 48 14 0 6 1 0 1 1 0 8 0 mppekey 1024 2 0 2 1 1 0 1 0 8 0 ppxss 1072 137 0 137 2 1 1 1 0 8 1 pppxif 1384 43 0 43 3 2 1 1 0 8 1 pfstscr 40 3 0 2 1 0 1 1 0 8 0 pfrktable 1344 3 0 3 1 1 0 1 0 8 0 pftag 88 1 0 0 1 0 1 1 0 8 0 pfqueue 320 2 0 1 1 0 1 1 0 8 0 pfstitem 24 2 0 0 1 0 1 1 0 8 0 pfstkey 128 5 0 3 1 0 1 1 0 8 0 pfstate 384 3 0 2 1 0 1 1 0 8 0 pfrule 1360 1 0 1 1 1 0 1 0 8 0 rttmr 136 1 0 1 1 1 0 1 0 8 0 art_heap8 4096 5 0 0 5 0 5 5 0 8 0 art_heap4 256 1114 0 728 37 3 34 37 0 8 2 art_table 40 1119 0 728 6 0 6 6 0 8 0 art_node 32 243 0 168 1 0 1 1 0 8 0 sysvmsgpl 40 4 0 2 1 0 1 1 0 8 0 semupl 112 2 0 2 2 1 1 1 0 8 1 semapl 112 283 0 273 1 0 1 1 0 8 0 shmpl 112 98 0 12 3 0 3 3 0 8 0 pool(0xffffffff83a09b70:shmpl): page inconsistency: page 0xfffffd80691fe000; 18 on list, 16 missing, 35 items per page dirhash 1024 41 0 24 3 0 3 3 0 8 0 dino2pl 256 7224 0 5769 92 0 92 92 0 8 0 ffsino 256 7224 0 5769 92 0 92 92 0 8 0 nchpl 144 11152 0 9449 64 0 64 64 0 8 0 rtmask 32 16 0 16 2 2 0 1 0 8 0 vnodes 216 5926 0 0 330 0 330 330 0 8 0 namei 1024 36303 0 36303 3 2 1 2 0 8 1 vcpupl 3904 10 0 1 2 0 2 2 0 8 0 vmpool 808 10 0 1 1 0 1 1 0 8 0 kstatmem 264 198 0 172 3 0 3 3 0 8 0 acpiwqpl 32 2 0 2 1 0 1 1 1 8 1 scsiplug 72 6 0 6 3 2 1 1 0 8 1 scxspl 216 53865 0 53865 11 9 2 8 1 8 2 plimitpl 152 636 0 619 1 0 1 1 0 8 0 sigapl 424 3383 0 3340 8 0 8 8 0 8 1 knotepl 120 133525 0 133474 41 28 13 22 0 8 8 kqueuepl 184 835 0 822 5 1 4 4 0 8 3 pipepl 304 381 0 352 5 2 3 5 0 8 0 fdescpl 448 3322 0 3292 5 1 4 5 0 8 0 filepl 120 21515 0 21298 21 6 15 15 0 8 5 lockfpl 104 1424 0 1422 3 2 1 2 0 8 0 lockfspl 48 464 0 462 1 0 1 1 0 8 0 sessionpl 144 34 0 26 1 0 1 1 0 8 0 pgrppl 48 80 0 64 1 0 1 1 0 8 0 ucredpl 104 3423 0 3412 1 0 1 1 0 8 0 zombiepl 144 3536 0 3536 2 1 1 1 0 8 1 processpl 1152 3383 0 3340 5 0 5 5 0 8 0 procpl 664 7163 0 7112 7 0 7 7 0 8 1 sosppl 176 11 0 11 3 2 1 1 0 8 1 sockpl 552 6791 0 6760 42 31 11 20 0 8 8 mcl64k 65536 403 0 403 2 1 1 2 0 8 1 mcl16k 16384 86 0 86 3 2 1 1 0 8 1 mcl12k 12288 54 0 53 3 2 1 1 0 8 0 mcl9k 9216 17 0 17 3 2 1 1 0 8 1 mcl8k 8192 183 0 182 3 2 1 1 0 8 0 mcl4k 4096 7040 0 6986 16 8 8 15 0 8 0 mcl2k2 2112 3 0 3 2 1 1 1 0 8 1 mcl2k 2048 2588 0 2584 4 3 1 3 0 8 0 mtagpl 96 105 0 25 4 1 3 3 0 8 0 mbufpl 256 59386 0 58268 245 172 73 235 0 8 1 bufpl 280 20568 0 14353 445 0 445 445 0 8 0 anonpl 24 428724 0 424513 89 32 57 57 0 187 21 amapchunkpl 152 94619 0 94145 61 31 30 36 0 158 10 amappl16 200 9000 0 8904 41 26 15 17 0 8 8 amappl15 192 5 0 5 1 1 0 1 0 8 0 amappl14 184 492 0 491 1 0 1 1 0 8 0 amappl13 176 140 0 130 1 0 1 1 0 8 0 amappl12 168 3613 0 3584 2 0 2 2 0 8 0 amappl11 160 6 0 6 1 1 0 1 0 8 0 amappl10 152 62 0 51 1 0 1 1 0 8 0 amappl9 144 263 0 263 1 1 0 1 0 8 0 amappl8 136 126 0 125 1 0 1 1 0 8 0 amappl7 128 167 0 156 1 0 1 1 0 8 0 amappl6 120 210 0 209 1 0 1 1 0 8 0 amappl5 112 105 0 97 1 0 1 1 0 8 0 amappl4 104 304 0 289 1 0 1 1 0 8 0 amappl3 96 19947 0 19835 4 0 4 4 0 8 0 amappl2 88 639 0 583 2 0 2 2 0 8 0 amappl1 80 23494 0 22951 18 5 13 15 0 8 0 amappl 88 26353 0 26195 5 0 5 5 0 92 0 uvmvnodes 80 157 0 0 4 0 4 4 0 8 0 dma65536 65536 2 0 2 1 1 0 1 0 8 0 dma4096 4096 2 0 2 2 1 1 1 0 8 1 dma1024 1024 3 0 2 1 0 1 1 0 8 0 dma512 512 1 0 1 1 1 0 1 0 8 0 dma256 256 7 0 7 1 1 0 1 0 8 0 dma128 128 254 0 254 1 1 0 1 0 8 0 dma64 64 8 0 8 2 2 0 1 0 8 0 dma32 32 7 0 7 1 1 0 1 0 8 0 dma16 16 19 0 18 1 0 1 1 0 8 0 aobjpl 72 110 0 13 2 0 2 2 0 8 0 uaddrrnd 24 3322 0 3292 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 3322 0 3292 1 0 1 1 0 8 0 vmmpekpl 168 21928 0 21862 3 0 3 3 0 8 0 vmmpepl 168 207885 0 205996 104 13 91 93 0 357 7 vmsppl 368 3321 0 3292 4 1 3 4 0 8 0 rwobjpl 40 50603 0 49444 14 0 14 14 0 8 0 pdppl 4096 6670 0 6595 141 66 75 82 0 8 0 pvpl 32 1428047 0 1416910 197 48 149 149 0 265 42 pmappl 216 3331 0 3293 3 0 3 3 0 8 0 extentpl 40 45 0 27 1 0 1 1 0 8 0 phpool 112 692 0 285 17 0 17 17 0 8 2 ddb> machine ddbcpu 0 No such command ddb> trace db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:438 panic(ffffffff83407964) at panic+0x1cf sys/kern/subr_prf.c:198 pool_do_get(ffffffff83a09b70,1,ffff8000384ecdb8) at pool_do_get+0x5bc pool_get(ffffffff83a09b70,1) at pool_get+0x11a sys/kern/subr_pool.c:-1 shmget_allocate_segment(ffff800038cfa560,ffff8000384ed000,5d,ffff8000384ecf50) at shmget_allocate_segment+0x1af sys/kern/sysv_shm.c:-1 sys_shmget(ffff800038cfa560,ffff8000384ed000,ffff8000384ecf50) at sys_shmget+0x195 sys/kern/sysv_shm.c:482 syscall(ffff8000384ed000) at syscall+0x962 mi_syscall sys/sys/syscall_mi.h:-1 [inline] syscall(ffff8000384ed000) at syscall+0x962 sys/arch/amd64/amd64/trap.c:783 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x3dc85378b60, count: -8 ddb> machine ddbcpu 1 No such command ddb> trace db_enter() at db_enter+0x25 sys/arch/amd64/amd64/db_interface.c:438 panic(ffffffff83407964) at panic+0x1cf sys/kern/subr_prf.c:198 pool_do_get(ffffffff83a09b70,1,ffff8000384ecdb8) at pool_do_get+0x5bc pool_get(ffffffff83a09b70,1) at pool_get+0x11a sys/kern/subr_pool.c:-1 shmget_allocate_segment(ffff800038cfa560,ffff8000384ed000,5d,ffff8000384ecf50) at shmget_allocate_segment+0x1af sys/kern/sysv_shm.c:-1 sys_shmget(ffff800038cfa560,ffff8000384ed000,ffff8000384ecf50) at sys_shmget+0x195 sys/kern/sysv_shm.c:482 syscall(ffff8000384ed000) at syscall+0x962 mi_syscall sys/sys/syscall_mi.h:-1 [inline] syscall(ffff8000384ed000) at syscall+0x962 sys/arch/amd64/amd64/trap.c:783 Xsyscall() at Xsyscall+0x128 end of kernel end trace frame: 0x3dc85378b60, count: -8