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BUG: KASAN: out-of-bounds in unwind_next_frame+0xd7/0xe0 arch/x86/kernel/unwind_frame.c:51
Read of size 8 at addr ffff8801b6dc7888 by task syz-executor5/9424

CPU: 0 PID: 9424 Comm: syz-executor5 Not tainted 4.9.82-gcdfc8df #45
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 ffff8801cb3e77b8 ffffffff81d94fc9 ffffea0006db71c0 ffff8801b6dc7888
 0000000000000000 ffff8801b6dc7890 0000000000000000 ffff8801cb3e77f0
 ffffffff8153e213 ffff8801b6dc7888 0000000000000008 0000000000000000
Call Trace:
 [<ffffffff81d94fc9>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81d94fc9>] dump_stack+0xc1/0x128 lib/dump_stack.c:51
 [<ffffffff8153e213>] print_address_description+0x73/0x280 mm/kasan/report.c:252
 [<ffffffff8153e735>] kasan_report_error mm/kasan/report.c:351 [inline]
 [<ffffffff8153e735>] kasan_report+0x275/0x360 mm/kasan/report.c:408
 [<ffffffff8153e894>] __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:429
 [<ffffffff810d4fe7>] unwind_next_frame+0xd7/0xe0 arch/x86/kernel/unwind_frame.c:51
 [<ffffffff8107c65d>] __save_stack_trace+0x7d/0xf0 arch/x86/kernel/stacktrace.c:42
 [<ffffffff8107c738>] save_stack_trace_tsk+0x48/0x70 arch/x86/kernel/stacktrace.c:71
 [<ffffffff816c5a76>] proc_pid_stack+0x146/0x230 fs/proc/base.c:466
 [<ffffffff816c7248>] proc_single_show+0xf8/0x170 fs/proc/base.c:768
 [<ffffffff815e92cf>] seq_read+0x32f/0x1290 fs/seq_file.c:240
 [<ffffffff8156cda1>] do_loop_readv_writev.part.17+0x141/0x1e0 fs/read_write.c:714
 [<ffffffff81571cc2>] do_loop_readv_writev fs/read_write.c:1105 [inline]
 [<ffffffff81571cc2>] compat_do_readv_writev+0x522/0x760 fs/read_write.c:1099
 [<ffffffff81571fe3>] compat_readv+0xe3/0x150 fs/read_write.c:1128
 [<ffffffff81572144>] do_compat_readv+0xf4/0x1d0 fs/read_write.c:1148
 [<ffffffff815746b6>] C_SYSC_readv fs/read_write.c:1160 [inline]
 [<ffffffff815746b6>] compat_SyS_readv+0x26/0x30 fs/read_write.c:1156
 [<ffffffff81006f97>] do_syscall_32_irqs_on arch/x86/entry/common.c:325 [inline]
 [<ffffffff81006f97>] do_fast_syscall_32+0x2f7/0x870 arch/x86/entry/common.c:387
 [<ffffffff838b6574>] entry_SYSENTER_compat+0x74/0x83 arch/x86/entry/entry_64_compat.S:127

The buggy address belongs to the page:
page:ffffea0006db71c0 count:0 mapcount:0 mapping:          (null) index:0x0
flags: 0x8000000000000000()
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8801b6dc7780: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8801b6dc7800: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff8801b6dc7880: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
                         ^
 ffff8801b6dc7900: 00 00 f1 f1 f1 f1 00 f2 f2 f2 f3 f3 f3 f3 00 00
 ffff8801b6dc7980: 00 00 00 00 00 00 00 00 00 00 00 00 00 f1 f1 f1
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