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BUG: KASAN: out-of-bounds in unwind_get_return_address+0x98/0xb0 arch/x86/kernel/unwind_frame.c:17
Read of size 8 at addr ffff8801ce0c7bc8 by task syz-executor3/18046

CPU: 0 PID: 18046 Comm: syz-executor3 Not tainted 4.9.102-gd054505 #34
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 ffff88019fe2f6d0 ffffffff81eb3489 ffffea00073831c0 ffff8801ce0c7bc8
 0000000000000000 ffff8801ce0c7bd0 ffff8801ceddcb40 ffff88019fe2f708
 ffffffff815676bb ffff8801ce0c7bc8 0000000000000008 0000000000000000
Call Trace:
 [<ffffffff81eb3489>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81eb3489>] dump_stack+0xc1/0x128 lib/dump_stack.c:51
 [<ffffffff815676bb>] print_address_description+0x6c/0x234 mm/kasan/report.c:256
 [<ffffffff81567ac5>] kasan_report_error mm/kasan/report.c:355 [inline]
 [<ffffffff81567ac5>] kasan_report.cold.6+0x242/0x2fe mm/kasan/report.c:412
 [<ffffffff8153b744>] __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433
 [<ffffffff810d2c08>] unwind_get_return_address+0x98/0xb0 arch/x86/kernel/unwind_frame.c:17
 [<ffffffff8107b95d>] __save_stack_trace+0x8d/0xf0 arch/x86/kernel/stacktrace.c:43
 [<ffffffff8107ba28>] save_stack_trace_tsk+0x48/0x70 arch/x86/kernel/stacktrace.c:71
 [<ffffffff816d75e8>] proc_pid_stack+0x148/0x220 fs/proc/base.c:467
 [<ffffffff816d8a8d>] proc_single_show+0xfd/0x170 fs/proc/base.c:769
 [<ffffffff815e9c23>] traverse+0x363/0x920 fs/seq_file.c:124
 [<ffffffff815ed529>] seq_read+0xd19/0x12e0 fs/seq_file.c:195
 [<ffffffff8156ef45>] do_loop_readv_writev.part.18+0xd5/0x280 fs/read_write.c:718
 [<ffffffff815740f7>] do_loop_readv_writev fs/read_write.c:707 [inline]
 [<ffffffff815740f7>] compat_do_readv_writev+0x567/0x7a0 fs/read_write.c:1091
 [<ffffffff81574412>] compat_readv+0xe2/0x150 fs/read_write.c:1120
 [<ffffffff815747a2>] do_compat_preadv64+0x152/0x180 fs/read_write.c:1169
 [<ffffffff81576d3b>] C_SYSC_preadv fs/read_write.c:1189 [inline]
 [<ffffffff81576d3b>] compat_SyS_preadv+0x3b/0x50 fs/read_write.c:1183
 [<ffffffff81006da7>] do_syscall_32_irqs_on arch/x86/entry/common.c:325 [inline]
 [<ffffffff81006da7>] do_fast_syscall_32+0x2f7/0x870 arch/x86/entry/common.c:387
 [<ffffffff839f8fd0>] entry_SYSENTER_compat+0x90/0xa2 arch/x86/entry/entry_64_compat.S:137

The buggy address belongs to the page:
page:ffffea00073831c0 count:0 mapcount:0 mapping:          (null) index:0x0
flags: 0x8000000000000000()
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8801ce0c7a80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8801ce0c7b00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff8801ce0c7b80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
                                                 ^
 ffff8801ce0c7c00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8801ce0c7c80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
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