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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 ffff880190b1f8e8 by task syz-executor6/15090

CPU: 1 PID: 15090 Comm: syz-executor6 Not tainted 4.9.107-g42a730a #48
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 ffff88018b9977c8 ffffffff81eb42a9 ffffea000642c7c0 ffff880190b1f8e8
 0000000000000000 ffff880190b1f8f0 ffff8801c56fb780 ffff88018b997800
 ffffffff81567f09 ffff880190b1f8e8 0000000000000008 0000000000000000
Call Trace:
 [<ffffffff81eb42a9>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81eb42a9>] dump_stack+0xc1/0x128 lib/dump_stack.c:51
 [<ffffffff81567f09>] print_address_description+0x6c/0x234 mm/kasan/report.c:256
 [<ffffffff81568313>] kasan_report_error mm/kasan/report.c:355 [inline]
 [<ffffffff81568313>] kasan_report.cold.6+0x242/0x2fe mm/kasan/report.c:412
 [<ffffffff8153bf64>] __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
 [<ffffffff8107b9ed>] __save_stack_trace+0x8d/0xf0 arch/x86/kernel/stacktrace.c:43
 [<ffffffff8107bab8>] save_stack_trace_tsk+0x48/0x70 arch/x86/kernel/stacktrace.c:71
 [<ffffffff816d80a8>] proc_pid_stack+0x148/0x220 fs/proc/base.c:469
 [<ffffffff816d979d>] proc_single_show+0xfd/0x170 fs/proc/base.c:771
 [<ffffffff815ed736>] seq_read+0x4b6/0x12e0 fs/seq_file.c:240
 [<ffffffff8156f795>] do_loop_readv_writev.part.18+0xd5/0x280 fs/read_write.c:718
 [<ffffffff815736e5>] do_loop_readv_writev fs/read_write.c:707 [inline]
 [<ffffffff815736e5>] do_readv_writev+0x565/0x7a0 fs/read_write.c:873
 [<ffffffff815739a4>] vfs_readv+0x84/0xc0 fs/read_write.c:897
 [<ffffffff81573dd7>] do_preadv+0x197/0x240 fs/read_write.c:974
 [<ffffffff81577390>] SYSC_preadv fs/read_write.c:1024 [inline]
 [<ffffffff81577390>] SyS_preadv+0x30/0x40 fs/read_write.c:1019
 [<ffffffff81006316>] do_syscall_64+0x1a6/0x490 arch/x86/entry/common.c:282
 [<ffffffff839f9b13>] entry_SYSCALL_64_after_swapgs+0x5d/0xdb

The buggy address belongs to the page:
page:ffffea000642c7c0 count:0 mapcount:0 mapping:          (null) index:0x0
flags: 0x8000000000000000()
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff880190b1f780: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff880190b1f800: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff880190b1f880: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
                                                             ^
 ffff880190b1f900: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff880190b1f980: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
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