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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 ffff8801831679d0 by task syz-executor0/20764

CPU: 1 PID: 20764 Comm: syz-executor0 Not tainted 4.9.135+ #61
 ffff8801ca17f7d8 ffffffff81b36bf9 ffffea00060c59c0 ffff8801831679d0
 0000000000000000 ffff8801831679d8 1ffff1003942ff27 ffff8801ca17f810
 ffffffff815009ad ffff8801831679d0 0000000000000008 0000000000000000
Call Trace:
 [<ffffffff81b36bf9>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81b36bf9>] dump_stack+0xc1/0x128 lib/dump_stack.c:51
 [<ffffffff815009ad>] print_address_description+0x6c/0x234 mm/kasan/report.c:256
 [<ffffffff81500db7>] kasan_report_error mm/kasan/report.c:355 [inline]
 [<ffffffff81500db7>] kasan_report.cold.6+0x242/0x2fe mm/kasan/report.c:412
 [<ffffffff814f2fc4>] __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433
 [<ffffffff810ac6af>] unwind_get_return_address+0x8f/0xa0 arch/x86/kernel/unwind_frame.c:17
 [<ffffffff81077b1d>] __save_stack_trace+0x8d/0xf0 arch/x86/kernel/stacktrace.c:43
 [<ffffffff81077be8>] save_stack_trace_tsk+0x48/0x70 arch/x86/kernel/stacktrace.c:71
 [<ffffffff816660bf>] proc_pid_stack+0x18f/0x290 fs/proc/base.c:483
 [<ffffffff8165e5fd>] proc_single_show+0xfd/0x170 fs/proc/base.c:785
 [<ffffffff81580b76>] seq_read+0x4b6/0x12d0 fs/seq_file.c:240
 [<ffffffff81509de5>] do_loop_readv_writev.part.1+0xd5/0x280 fs/read_write.c:718
 [<ffffffff8150b48e>] do_loop_readv_writev fs/read_write.c:707 [inline]
 [<ffffffff8150b48e>] do_readv_writev+0x56e/0x7b0 fs/read_write.c:873
 [<ffffffff8150b754>] vfs_readv+0x84/0xc0 fs/read_write.c:897
 [<ffffffff8150bb87>] do_preadv+0x197/0x240 fs/read_write.c:974
 [<ffffffff8150f140>] SYSC_preadv fs/read_write.c:1024 [inline]
 [<ffffffff8150f140>] SyS_preadv+0x30/0x40 fs/read_write.c:1019
 [<ffffffff810056ef>] do_syscall_64+0x19f/0x550 arch/x86/entry/common.c:285
 [<ffffffff8280ac13>] entry_SYSCALL_64_after_swapgs+0x5d/0xdb

The buggy address belongs to the page:
page:ffffea00060c59c0 count:0 mapcount:0 mapping:          (null) index:0x0
flags: 0x4000000000000000()
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff880183167880: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff880183167900: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff880183167980: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
                                                    ^
 ffff880183167a00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff880183167a80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
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