================================================================== 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 ffff88018966e950 by task syz-executor7/7471 CPU: 0 PID: 7471 Comm: syz-executor7 Not tainted 4.17.0-rc3+ #34 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 schedule+0xef/0x430 kernel/sched/core.c:3549 freezable_schedule include/linux/freezer.h:172 [inline] futex_wait_queue_me+0x3e8/0x820 kernel/futex.c:2530 futex_wait+0x450/0x9f0 kernel/futex.c:2645 do_futex+0x336/0x27d0 kernel/futex.c:3527 __do_sys_futex kernel/futex.c:3587 [inline] __se_sys_futex kernel/futex.c:3555 [inline] __x64_sys_futex+0x46a/0x680 kernel/futex.c:3555 do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x455979 RSP: 002b:00007f6772e27ce8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: ffffffffffffffda RBX: 000000000072bec8 RCX: 0000000000455979 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 000000000072bec8 RBP: 000000000072bec8 R08: 0000000000000000 R09: 000000000072bea0 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fffb4ada9ef R14: 00007f6772e289c0 R15: 0000000000000000 The buggy address belongs to the page: page:ffffea0006259b80 count:0 mapcount:0 mapping:0000000000000000 index:0x0 flags: 0x2fffc0000000000() raw: 02fffc0000000000 0000000000000000 0000000000000000 00000000ffffffff raw: 0000000000000000 ffffea0006259ba0 0000000000000000 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88018966e800: 00 00 00 00 00 00 00 00 00 f1 f1 f1 f1 00 00 00 ffff88018966e880: 00 00 00 00 00 00 00 00 f2 f3 f3 f3 f3 00 00 00 >ffff88018966e900: 00 00 00 00 00 00 00 00 00 00 f1 f1 f1 f1 04 f2 ^ ffff88018966e980: f2 f2 f2 f2 f2 f2 f8 f2 f2 f2 f2 f2 f2 f2 00 00 ffff88018966ea00: 00 f2 f3 f3 f3 f3 00 00 00 00 00 00 00 00 00 00 ==================================================================