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BUG: KASAN: out-of-bounds in unwind_get_return_address+0x8f/0xa0 arch/x86/kernel/unwind_frame.c:17
Read of size 8 at addr ffff8801c5407bd0 by task syz-executor2/9267

CPU: 0 PID: 9267 Comm: syz-executor2 Not tainted 4.9.131+ #102
 ffff8801d6ed76f0 ffffffff81b37029 ffffea00071501c0 ffff8801c5407bd0
 0000000000000000 ffff8801c5407bd8 ffff8801d2e718c0 ffff8801d6ed7728
 ffffffff81500aed ffff8801c5407bd0 0000000000000008 0000000000000000
Call Trace:
 [<ffffffff81b37029>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81b37029>] dump_stack+0xc1/0x128 lib/dump_stack.c:51
 [<ffffffff81500aed>] print_address_description+0x6c/0x234 mm/kasan/report.c:256
 [<ffffffff81500ef7>] kasan_report_error mm/kasan/report.c:355 [inline]
 [<ffffffff81500ef7>] kasan_report.cold.6+0x242/0x2fe mm/kasan/report.c:412
 [<ffffffff814f3104>] __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433
 [<ffffffff810ac7cf>] unwind_get_return_address+0x8f/0xa0 arch/x86/kernel/unwind_frame.c:17
 [<ffffffff81077c3d>] __save_stack_trace+0x8d/0xf0 arch/x86/kernel/stacktrace.c:43
 [<ffffffff81077d08>] save_stack_trace_tsk+0x48/0x70 arch/x86/kernel/stacktrace.c:71
 [<ffffffff81666158>] proc_pid_stack+0x148/0x220 fs/proc/base.c:469
input: 
 as /devices/virtual/input/input42
 [<ffffffff8165e6dd>] proc_single_show+0xfd/0x170 fs/proc/base.c:771
 [<ffffffff8157fe83>] traverse+0x363/0x920 fs/seq_file.c:124
 [<ffffffff8158151b>] seq_read+0xd1b/0x12d0 fs/seq_file.c:195
 [<ffffffff81509f25>] do_loop_readv_writev.part.1+0xd5/0x280 fs/read_write.c:718
 [<ffffffff8150b5ce>] do_loop_readv_writev fs/read_write.c:707 [inline]
 [<ffffffff8150b5ce>] do_readv_writev+0x56e/0x7b0 fs/read_write.c:873
 [<ffffffff8150b894>] vfs_readv+0x84/0xc0 fs/read_write.c:897
 [<ffffffff8150bcc7>] do_preadv+0x197/0x240 fs/read_write.c:974
 [<ffffffff8150f280>] SYSC_preadv fs/read_write.c:1024 [inline]
 [<ffffffff8150f280>] SyS_preadv+0x30/0x40 fs/read_write.c:1019
 [<ffffffff810056ef>] do_syscall_64+0x19f/0x550 arch/x86/entry/common.c:285
 [<ffffffff828037d3>] entry_SYSCALL_64_after_swapgs+0x5d/0xdb

The buggy address belongs to the page:
page:ffffea00071501c0 count:0 mapcount:0 mapping:          (null) index:0x0
flags: 0x4000000000000000()
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8801c5407a80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8801c5407b00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff8801c5407b80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
                                                    ^
 ffff8801c5407c00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8801c5407c80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
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