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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+0x3a7/0x3c0 arch/x86/kernel/unwind_frame.c:76
Read of size 8 at addr ffff8801b632fbd8 by task syzkaller776934/8981

CPU: 0 PID: 8981 Comm: syzkaller776934 Not tainted 4.9.81-gf8bbe51 #32
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 ffff8801b5e07788 ffffffff81d94e69 ffffea0006d8cbc0 ffff8801b632fbd8
 0000000000000000 ffff8801b632fbe0 ffff8801b5e078b8 ffff8801b5e077c0
 ffffffff8153e1e3 ffff8801b632fbd8 0000000000000008 0000000000000000
Call Trace:
 [<ffffffff81d94e69>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81d94e69>] dump_stack+0xc1/0x128 lib/dump_stack.c:51
 [<ffffffff8153e1e3>] print_address_description+0x73/0x280 mm/kasan/report.c:252
 [<ffffffff8153e705>] kasan_report_error mm/kasan/report.c:351 [inline]
 [<ffffffff8153e705>] kasan_report+0x275/0x360 mm/kasan/report.c:408
 [<ffffffff8153e864>] __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:429
 [<ffffffff810d5397>] get_frame_pointer arch/x86/include/asm/stacktrace.h:64 [inline]
 [<ffffffff810d5397>] __unwind_start+0x3a7/0x3c0 arch/x86/kernel/unwind_frame.c:76
 [<ffffffff8107c639>] unwind_start arch/x86/include/asm/unwind.h:39 [inline]
 [<ffffffff8107c639>] __save_stack_trace+0x59/0xf0 arch/x86/kernel/stacktrace.c:41
 [<ffffffff8107c738>] save_stack_trace_tsk+0x48/0x70 arch/x86/kernel/stacktrace.c:71
 [<ffffffff816c59d6>] proc_pid_stack+0x146/0x230 fs/proc/base.c:466
 [<ffffffff816c71a8>] proc_single_show+0xf8/0x170 fs/proc/base.c:768
 [<ffffffff815e925f>] seq_read+0x32f/0x1290 fs/seq_file.c:240
 [<ffffffff8156cd71>] do_loop_readv_writev.part.17+0x141/0x1e0 fs/read_write.c:714
 [<ffffffff81570be0>] do_loop_readv_writev fs/read_write.c:880 [inline]
 [<ffffffff81570be0>] do_readv_writev+0x520/0x750 fs/read_write.c:874
 [<ffffffff81570e94>] vfs_readv+0x84/0xc0 fs/read_write.c:898
 [<ffffffff81570fb6>] do_readv+0xe6/0x250 fs/read_write.c:924
 [<ffffffff815744a7>] SYSC_readv fs/read_write.c:1011 [inline]
 [<ffffffff815744a7>] SyS_readv+0x27/0x30 fs/read_write.c:1008
 [<ffffffff81006505>] do_syscall_64+0x1a5/0x490 arch/x86/entry/common.c:282
 [<ffffffff838b3dbd>] entry_SYSCALL_64_after_swapgs+0x47/0xc5

The buggy address belongs to the page:
page:ffffea0006d8cbc0 count:0 mapcount:0 mapping:          (null) index:0x0
flags: 0x8000000000000000()
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8801b632fa80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8801b632fb00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff8801b632fb80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
                                                       ^
 ffff8801b632fc00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8801b632fc80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
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