login: panic: pool_do_get: shmpl free list modified: page 0xfffffd807e864000; item addr 0xfffffd807e864700; offset 0x10=0xdeadbe00 Stopped at db_enter+0x18: addq $0x8,%rsp TID PID UID PRFLAGS PFLAGS CPU COMMAND 156438 58786 32767 0x10 0 0 syz-executor.0 *369610 58786 32767 0x10 0x4000000 1K syz-executor.0 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(ffffffff823682b8,1,ffff800020c03324) at pool_do_get+0x4bf sys/kern/subr_pool.c:750 pool_get() at pool_get+0x106 sys/kern/subr_pool.c:587 shmget_allocate_segment(ffff800020b39080,ffff800020c03508,3,ffff800020c034f0) at shmget_allocate_segment+0x15e sys/kern/sysv_shm.c:409 sys_shmget(ffff800020b39080,ffff800020c03508,ffff800020c034f0) at sys_shmget+0x13f sys/kern/sysv_shm.c:472 syscall(ffff800020c035a0) at syscall+0x5b8 mi_syscall sys/sys/syscall_mi.h:99 [inline] syscall(ffff800020c035a0) at syscall+0x5b8 sys/arch/amd64/amd64/trap.c:574 Xsyscall(6,0,fffffffffffffff4,0,4,c5d5173c010) at Xsyscall+0x128 end of kernel end trace frame: 0xc5fc7290bd0, 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 0xfffffd807e864000; item addr 0xfffffd807e864700; offset 0x10=0xdeadbe00 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(ffffffff823682b8,1,ffff800020c03324) at pool_do_get+0x4bf sys/kern/subr_pool.c:750 pool_get() at pool_get+0x106 sys/kern/subr_pool.c:587 shmget_allocate_segment(ffff800020b39080,ffff800020c03508,3,ffff800020c034f0) at shmget_allocate_segment+0x15e sys/kern/sysv_shm.c:409 sys_shmget(ffff800020b39080,ffff800020c03508,ffff800020c034f0) at sys_shmget+0x13f sys/kern/sysv_shm.c:472 syscall(ffff800020c035a0) at syscall+0x5b8 mi_syscall sys/sys/syscall_mi.h:99 [inline] syscall(ffff800020c035a0) at syscall+0x5b8 sys/arch/amd64/amd64/trap.c:574 Xsyscall(6,0,fffffffffffffff4,0,4,c5d5173c010) at Xsyscall+0x128 end of kernel end trace frame: 0xc5fc7290bd0, count: -8 ddb{1}> show registers rdi 0xffffffff81454e67 db_enter+0x17 rsi 0x2be5 __ALIGN_SIZE+0x1be5 rbp 0xffff800020c03160 rbx 0xffff800020c03210 rdx 0x2be6 __ALIGN_SIZE+0x1be6 rcx 0xffff800001b4c000 rax 0xffff800001b4c000 r8 0xffffffff81cae0b3 kprintf+0x183 r9 0x1 r10 0x25 r11 0xc52cd8b3022dcd4 r12 0x3000000008 r13 0xffff800020c03170 r14 0x100 r15 0x1 rip 0xffffffff81454e68 db_enter+0x18 cs 0x8 rflags 0x246 rsp 0xffff800020c03150 ss 0x10 db_enter+0x18: addq $0x8,%rsp ddb{1}> show proc PROC (syz-executor.0) pid=369610 stat=onproc flags process=10 proc=4000000 pri=86, usrpri=86, nice=20 forw=0xffffffffffffffff, list=0xffff800020b39788,0xffff800020b39540 process=0xffff800020b3a010 user=0xffff800020bfe000, vmspace=0xfffffd806e936008 estcpu=36, cpticks=4, pctcpu=0.0 user=0, sys=1, intr=0 ddb{1}> ps PID TID PPID UID S FLAGS WAIT COMMAND 58786 156438 59107 32767 7 0x10 syz-executor.0 *58786 369610 59107 32767 7 0x4000010 syz-executor.0 58786 193342 59107 32767 3 0x4000090 fsleep syz-executor.0 58786 161029 59107 32767 3 0x4000090 fsleep syz-executor.0 58786 93889 59107 32767 3 0x4000090 fsleep syz-executor.0 59107 14941 68118 32767 3 0x90 nanosleep syz-executor.0 68118 443810 62830 0 3 0x82 wait syz-executor.0 23691 383721 0 0 3 0x14200 bored sosplice 62830 450320 29406 0 3 0x82 thrsleep syz-fuzzer 62830 346888 29406 0 3 0x4000082 thrsleep syz-fuzzer 62830 47834 29406 0 3 0x4000082 thrsleep syz-fuzzer 62830 107429 29406 0 3 0x4000082 kqread syz-fuzzer 62830 450344 29406 0 3 0x4000082 thrsleep syz-fuzzer 62830 81420 29406 0 3 0x4000082 thrsleep syz-fuzzer 62830 485763 29406 0 3 0x4000082 thrsleep syz-fuzzer 62830 182004 29406 0 3 0x4000082 thrsleep syz-fuzzer 62830 34748 29406 0 3 0x4000082 thrsleep syz-fuzzer 62830 129373 29406 0 3 0x4000082 thrsleep syz-fuzzer 29406 299212 9979 0 3 0x10008a pause ksh 9979 231791 30615 0 3 0x92 select sshd 48111 52791 1 0 3 0x100083 ttyin getty 30615 142364 1 0 3 0x80 select sshd 7674 383578 61921 73 3 0x100090 kqread syslogd 61921 222221 1 0 3 0x100082 netio syslogd 85547 422983 1 77 3 0x100090 poll dhclient 358 492464 1 0 3 0x80 poll dhclient 68334 308870 0 0 3 0x14200 pgzero zerothread 9333 15228 0 0 3 0x14200 aiodoned aiodoned 86238 16857 0 0 3 0x14200 syncer update 42520 301999 0 0 3 0x14200 cleaner cleaner 67502 315612 0 0 3 0x14200 reaper reaper 98445 424503 0 0 3 0x14200 pgdaemon pagedaemon 33007 215598 0 0 3 0x14200 bored crynlk 72813 378825 0 0 3 0x14200 bored crypto 86578 474982 0 0 3 0x40014200 acpi0 acpi0 16279 514782 0 0 3 0x40014200 idle1 56334 388129 0 0 3 0x14200 bored softnet 39734 171307 0 0 3 0x14200 bored systqmp 46188 351047 0 0 3 0x14200 bored systq 82028 413172 0 0 3 0x40014200 bored softclock 50246 112099 0 0 3 0x40014200 idle0 62219 489783 0 0 3 0x14200 bored smr 1 390872 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 (0xffffffff823682c8) locked @ /syzkaller/managers/setuid/kernel/sys/kern/subr_pool.c:583 #0 witness_lock+0x594 sys/kern/subr_witness.c:1201 #1 pool_get+0xda 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+0x5b8 mi_syscall sys/sys/syscall_mi.h:99 [inline] #4 syscall+0x5b8 sys/arch/amd64/amd64/trap.c:574 #5 Xsyscall+0x128 Process 58786 (syz-executor.0) thread 0xffff800020b39080 (369610) exclusive kernel_lock &kernel_lock r = 0 (0xffffffff82347588) locked @ /syzkaller/managers/setuid/kernel/sys/sys/syscall_mi.h:90 #0 witness_lock+0x594 sys/kern/subr_witness.c:1201 #1 syscall+0x48b mi_syscall sys/sys/syscall_mi.h:91 [inline] #1 syscall+0x48b sys/arch/amd64/amd64/trap.c:574 #2 Xsyscall+0x128 exclusive mutex shmpl r = 0 (0xffffffff823682c8) locked @ /syzkaller/managers/setuid/kernel/sys/kern/subr_pool.c:583 #0 witness_lock+0x594 sys/kern/subr_witness.c:1201 #1 pool_get+0xda 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+0x5b8 mi_syscall sys/sys/syscall_mi.h:99 [inline] #4 syscall+0x5b8 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 9455 6318K 6321K 78643K 10577 0 0 pcb 23 9K 10K 78643K 234 0 0 rtable 79 2K 3K 78643K 380 0 0 ifaddr 28 8K 9K 78643K 71 0 0 counters 39 33K 33K 78643K 39 0 0 ioctlops 0 0K 2K 78643K 23 0 0 iov 0 0K 16K 78643K 32 0 0 mount 1 1K 1K 78643K 1 0 0 vnodes 1201 75K 75K 78643K 1380 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 7 0 0 VM map 2 1K 1K 78643K 2 0 0 sem 12 1K 1K 78643K 60 0 0 dirhash 12 2K 2K 78643K 12 0 0 ACPI 1808 196K 290K 78643K 12628 0 0 file desc 5 13K 33K 78643K 384 0 0 sigio 0 0K 0K 78643K 8 0 0 proc 41 38K 58K 78643K 439 0 0 subproc 34 34817K 69634K 78643K 272 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 88 0 0 in_multi 22 1K 2K 78643K 113 0 0 ether_multi 1 0K 0K 78643K 4 0 0 ISOFS mount 1 32K 32K 78643K 1 0 0 MSDOSFS mount 1 16K 16K 78643K 1 0 0 ttys 60 265K 265K 78643K 60 0 0 exec 0 0K 1K 78643K 219 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 76 12K 29K 78643K 1942 0 0 UVM aobj 27 2K 2K 78643K 28 0 0 memdesc 1 4K 4K 78643K 1 0 0 crypto data 1 1K 1K 78643K 1 0 0 ip6_options 0 0K 0K 78643K 38 0 0 NDP 4 0K 0K 78643K 27 0 0 temp 79 2372K 2439K 78643K 4112 0 0 kqueue 0 0K 0K 78643K 11 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 10 0 7 1 0 1 1 0 8 0 inpcbpl 280 273 0 265 1 0 1 1 0 8 0 plimitpl 152 45 0 38 1 0 1 1 0 8 0 plcache 128 20 0 0 1 0 1 1 0 8 0 rtentry 112 95 0 64 2 0 2 2 0 8 0 syncache 264 4 0 4 1 1 0 1 0 8 0 tcpqe 32 8 0 8 1 1 0 1 0 8 0 tcpcb 544 90 0 86 1 0 1 1 0 8 0 nd6 48 16 0 14 1 0 1 1 0 8 0 art_heap8 4096 1 0 0 1 0 1 1 0 8 0 art_heap4 256 430 0 286 12 0 12 12 0 8 2 art_table 32 431 0 286 2 0 2 2 0 8 0 art_node 16 94 0 66 1 0 1 1 0 8 0 sysvmsgpl 40 6 0 2 1 0 1 1 0 8 0 semupl 112 1 0 1 1 1 0 1 0 8 0 semapl 112 58 0 48 1 0 1 1 0 8 0 shmpl 112 26 0 1 1 0 1 1 0 8 0 shmpl: pool(0xffffffff823682b8:shmpl): page inconsistency: page 0xfffffd807e864000; item ordinal 0; addr 0x4d8ad63899581401 dirhash 1024 17 0 0 3 0 3 3 0 8 0 dino1pl 128 1889 0 461 47 0 47 47 0 8 0 ffsino 272 1889 0 461 96 0 96 96 0 8 0 nchpl 144 2611 0 1000 61 0 61 61 0 8 0 uvmvnodes 72 2034 0 0 37 0 37 37 0 8 0 vnodes 200 2034 0 0 108 0 108 108 0 8 0 namei 1024 7366 0 7366 2 1 1 1 0 8 1 percpumem 16 30 0 0 1 0 1 1 0 8 0 scxspl 192 6652 0 6652 9 8 1 6 0 8 1 sigapl 432 536 0 523 3 1 2 3 0 8 0 futexpl 56 3966 0 3963 1 0 1 1 0 8 0 knotepl 112 289 0 276 1 0 1 1 0 8 0 kqueuepl 104 100 0 97 1 0 1 1 0 8 0 pipepl 112 340 0 327 2 1 1 1 0 8 0 fdescpl 488 537 0 523 3 0 3 3 0 8 0 filepl 152 3226 0 3150 6 1 5 5 0 8 1 lockfpl 104 102 0 101 2 1 1 1 0 8 0 lockfspl 32 201 0 200 2 1 1 1 0 8 0 sessionpl 112 23 0 14 1 0 1 1 0 8 0 pgrppl 48 26 0 17 1 0 1 1 0 8 0 ucredpl 96 748 0 740 1 0 1 1 0 8 0 zombiepl 144 523 0 523 2 1 1 1 0 8 1 processpl 840 553 0 523 4 0 4 4 0 8 0 procpl 600 1249 0 1206 4 0 4 4 0 8 0 srpgc 64 42 0 42 2 1 1 1 0 8 1 sosppl 128 7 0 7 1 1 0 1 0 8 0 sockpl 384 501 0 483 4 1 3 3 0 8 1 mcl64k 65536 3 0 0 1 0 1 1 0 8 0 mcl16k 16384 1 0 0 1 0 1 1 0 8 0 mcl12k 12288 4 0 0 1 0 1 1 0 8 0 mcl9k 9216 2 0 0 1 0 1 1 0 8 0 mcl8k 8192 4 0 0 1 0 1 1 0 8 0 mcl4k 4096 4 0 0 1 0 1 1 0 8 0 mcl2k2 2112 2 0 0 1 0 1 1 0 8 0 mcl2k 2048 121 0 0 15 0 15 15 0 8 0 mtagpl 80 1 0 0 1 0 1 1 0 8 0 mbufpl 256 178 0 0 10 1 9 9 0 8 0 bufpl 256 6098 0 1122 311 0 311 311 0 8 0 anonpl 16 70647 0 64916 47 6 41 43 0 125 13 amapchunkpl 152 3336 0 3250 11 2 9 9 0 158 4 amappl16 192 2103 0 1754 34 8 26 30 0 8 8 amappl15 184 163 0 159 1 0 1 1 0 8 0 amappl14 176 73 0 70 2 1 1 1 0 8 0 amappl13 168 191 0 183 1 0 1 1 0 8 0 amappl12 160 16 0 15 1 0 1 1 0 8 0 amappl11 152 131 0 120 1 0 1 1 0 8 0 amappl10 144 74 0 70 2 1 1 1 0 8 0 amappl9 136 638 0 636 1 0 1 1 0 8 0 amappl8 128 217 0 203 1 0 1 1 0 8 0 amappl7 120 46 0 38 1 0 1 1 0 8 0 amappl6 112 173 0 165 1 0 1 1 0 8 0 amappl5 104 127 0 115 1 0 1 1 0 8 0 amappl4 96 756 0 725 2 1 1 2 0 8 0 amappl3 88 161 0 156 1 0 1 1 0 8 0 amappl2 80 3556 0 3503 2 0 2 2 0 8 0 amappl1 72 21156 0 20727 23 13 10 19 0 8 0 amappl 72 1507 0 1473 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 27 0 1 1 0 1 1 0 8 0 uaddrrnd 24 537 0 523 1 0 1 1 0 8 0 uaddrbest 32 2 0 0 1 0 1 1 0 8 0 uaddr 24 537 0 523 1 0 1 1 0 8 0 vmmpekpl 168 8305 0 8280 2 0 2 2 0 8 0 vmmpepl 168 66161 0 64850 93 18 75 75 0 357 16 vmsppl 360 536 0 523 2 0 2 2 0 8 0 pdppl 4096 1082 0 1046 6 0 6 6 0 8 0 pvpl 32 212951 0 203561 132 20 112 115 0 265 29 pmappl 224 536 0 523 3 2 1 2 0 8 0 extentpl 40 39 0 25 1 0 1 1 0 8 0 phpool 112 463 0 4 14 0 14 14 0 8 0