================================================================== BUG: KASAN: stack-out-of-bounds in __read_once_size include/linux/compiler.h:188 [inline] BUG: KASAN: stack-out-of-bounds in update_stack_state+0x5d9/0x670 arch/x86/kernel/unwind_frame.c:270 Read of size 8 at addr ffff8801c583e618 by task syz-executor0/7145 CPU: 0 PID: 7145 Comm: syz-executor0 Not tainted 4.17.0-rc2+ #22 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1b9/0x294 lib/dump_stack.c:113 print_address_description+0x6c/0x20b mm/kasan/report.c:256 kasan_report_error mm/kasan/report.c:354 [inline] kasan_report.cold.7+0x242/0x2fe mm/kasan/report.c:412 __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433 __read_once_size include/linux/compiler.h:188 [inline] update_stack_state+0x5d9/0x670 arch/x86/kernel/unwind_frame.c:270 __unwind_start+0xf9/0x330 arch/x86/kernel/unwind_frame.c:404 unwind_start arch/x86/include/asm/unwind.h:54 [inline] perf_callchain_kernel+0x2ab/0x630 arch/x86/events/core.c:2350 get_perf_callchain+0x515/0xb20 kernel/events/callchain.c:202 perf_callchain kernel/events/core.c:6357 [inline] perf_prepare_sample+0x123d/0x1900 kernel/events/core.c:6383 __perf_event_output kernel/events/core.c:6497 [inline] perf_event_output_forward+0x10a/0x2b0 kernel/events/core.c:6515 __perf_event_overflow+0x231/0x4b0 kernel/events/core.c:7755 perf_swevent_overflow+0xad/0x150 kernel/events/core.c:7831 perf_swevent_event+0x1f0/0x2e0 kernel/events/core.c:7864 do_perf_sw_event kernel/events/core.c:7972 [inline] ___perf_sw_event+0x486/0x780 kernel/events/core.c:8003 perf_sw_event_sched include/linux/perf_event.h:1062 [inline] perf_event_task_sched_out include/linux/perf_event.h:1100 [inline] prepare_task_switch kernel/sched/core.c:2636 [inline] context_switch kernel/sched/core.c:2813 [inline] __schedule+0xf3f/0x1e30 kernel/sched/core.c:3490 preempt_schedule_common+0x22/0x60 kernel/sched/core.c:3629 _cond_resched+0x1d/0x30 kernel/sched/core.c:4978 lock_page_or_retry include/linux/pagemap.h:509 [inline] filemap_fault+0x37a/0x2200 mm/filemap.c:2530 ext4_filemap_fault+0x82/0xad fs/ext4/inode.c:6183 __do_fault+0xe6/0x430 mm/memory.c:3222 do_read_fault mm/memory.c:3632 [inline] do_fault mm/memory.c:3732 [inline] handle_pte_fault mm/memory.c:3963 [inline] __handle_mm_fault+0x2ba6/0x4310 mm/memory.c:4087 handle_mm_fault+0x53a/0xc70 mm/memory.c:4124 faultin_page mm/gup.c:502 [inline] __get_user_pages+0x783/0x1a10 mm/gup.c:699 populate_vma_page_range+0x2db/0x3c0 mm/gup.c:1203 __mm_populate+0x2c6/0x500 mm/gup.c:1253 mm_populate include/linux/mm.h:2246 [inline] __do_sys_mlockall mm/mlock.c:817 [inline] __se_sys_mlockall mm/mlock.c:794 [inline] __x64_sys_mlockall+0x464/0x640 mm/mlock.c:794 do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x455979 RSP: 002b:00007f9379536c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000097 RAX: ffffffffffffffda RBX: 00007f93795376d4 RCX: 0000000000455979 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000001 RBP: 000000000072bea0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000401 R14: 00000000006f90b8 R15: 0000000000000000 The buggy address belongs to the page: page:ffffea0007160f80 count:0 mapcount:0 mapping:0000000000000000 index:0xffff8801c583e500 flags: 0x2fffc0000000000() raw: 02fffc0000000000 0000000000000000 ffff8801c583e500 00000000ffffffff raw: dead000000000100 dead000000000200 ffff8801da988dc0 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8801c583e500: 00 f1 f1 f1 f1 00 00 00 00 00 00 00 00 00 00 00 ffff8801c583e580: f2 f3 f3 f3 f3 00 00 00 00 00 00 00 00 00 00 00 >ffff8801c583e600: 00 00 f1 f1 f1 f1 04 f2 f2 f2 f2 f2 f2 f2 f8 f2 ^ ffff8801c583e680: f2 f2 f2 f2 f2 f2 00 00 00 f2 f3 f3 f3 f3 00 00 ffff8801c583e700: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 f1 ==================================================================