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BUG: KASAN: out-of-bounds in get_frame_pointer arch/x86/include/asm/stacktrace.h:64 [inline]
BUG: KASAN: out-of-bounds in __unwind_start+0x37c/0x3c0 arch/x86/kernel/unwind_frame.c:76
Read of size 8 at addr ffff8801d8e57820 by task syzkaller687868/3823

CPU: 0 PID: 3823 Comm: syzkaller687868 Not tainted 4.9.95-g142d4b5 #7
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 ffff8801d8477058 ffffffff81eb0f89 ffffea00076395c0 ffff8801d8e57820
 0000000000000000 ffff8801d8e57828 ffff8801d8477190 ffff8801d8477090
 ffffffff815653cb ffff8801d8e57820 0000000000000008 0000000000000000
Call Trace:
 [<ffffffff81eb0f89>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81eb0f89>] dump_stack+0xc1/0x128 lib/dump_stack.c:51
 [<ffffffff815653cb>] print_address_description+0x6c/0x234 mm/kasan/report.c:256
 [<ffffffff815657d5>] kasan_report_error mm/kasan/report.c:355 [inline]
 [<ffffffff815657d5>] kasan_report.cold.6+0x242/0x2fe mm/kasan/report.c:412
 [<ffffffff81539454>] __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433
 [<ffffffff810d11ec>] get_frame_pointer arch/x86/include/asm/stacktrace.h:64 [inline]
 [<ffffffff810d11ec>] __unwind_start+0x37c/0x3c0 arch/x86/kernel/unwind_frame.c:76
 [<ffffffff8107ada9>] unwind_start arch/x86/include/asm/unwind.h:39 [inline]
 [<ffffffff8107ada9>] __save_stack_trace+0x59/0xf0 arch/x86/kernel/stacktrace.c:41
 [<ffffffff8107aea8>] save_stack_trace_tsk+0x48/0x70 arch/x86/kernel/stacktrace.c:71
 [<ffffffff816d53a8>] proc_pid_stack+0x148/0x220 fs/proc/base.c:467
 [<ffffffff816d684d>] proc_single_show+0xfd/0x170 fs/proc/base.c:769
 [<ffffffff815e7933>] traverse+0x363/0x920 fs/seq_file.c:124
 [<ffffffff815eb239>] seq_read+0xd19/0x12e0 fs/seq_file.c:195
 [<ffffffff8156cc55>] do_loop_readv_writev.part.18+0xd5/0x280 fs/read_write.c:718
 [<ffffffff81570ba5>] do_loop_readv_writev fs/read_write.c:707 [inline]
 [<ffffffff81570ba5>] do_readv_writev+0x565/0x7a0 fs/read_write.c:873
 [<ffffffff81570e64>] vfs_readv+0x84/0xc0 fs/read_write.c:897
 [<ffffffff81611dbb>] kernel_readv fs/splice.c:363 [inline]
 [<ffffffff81611dbb>] default_file_splice_read+0x44b/0x7e0 fs/splice.c:435
 [<ffffffff81610ebc>] do_splice_to+0x10c/0x170 fs/splice.c:899
 [<ffffffff8161115f>] splice_direct_to_actor+0x23f/0x7e0 fs/splice.c:971
 [<ffffffff816118a3>] do_splice_direct+0x1a3/0x270 fs/splice.c:1080
 [<ffffffff81572e70>] do_sendfile+0x4f0/0xc60 fs/read_write.c:1393
 [<ffffffff81574ef1>] SYSC_sendfile64 fs/read_write.c:1448 [inline]
 [<ffffffff81574ef1>] SyS_sendfile64+0xd1/0x160 fs/read_write.c:1440
 [<ffffffff81006316>] do_syscall_64+0x1a6/0x490 arch/x86/entry/common.c:282
 [<ffffffff839f3313>] entry_SYSCALL_64_after_swapgs+0x5d/0xdb

The buggy address belongs to the page:
page:ffffea00076395c0 count:0 mapcount:0 mapping:          (null) index:0x0
flags: 0x8000000000000000()
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8801d8e57700: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8801d8e57780: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff8801d8e57800: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
                                  ^
 ffff8801d8e57880: 00 00 00 00 00 00 00 00 00 00 00 f1 f1 f1 f1 00
 ffff8801d8e57900: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
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