==================================================================
BUG: KASAN: stack-out-of-bounds in unwind_get_return_address+0x8f/0xa0 arch/x86/kernel/unwind_frame.c:17
Read of size 8 at addr ffff8801addb7de8 by task syz-executor5/21080

CPU: 0 PID: 21080 Comm: syz-executor5 Not tainted 4.9.130+ #2
 ffff8801d2dff7c8 ffffffff81b36c99 ffffea0006b76dc0 ffff8801addb7de8
 0000000000000000 ffff8801addb7de8 ffff8801c977b280 ffff8801d2dff800
 ffffffff8150080d ffff8801addb7de8 0000000000000008 0000000000000000
Call Trace:
 [<ffffffff81b36c99>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81b36c99>] dump_stack+0xc1/0x128 lib/dump_stack.c:51
 [<ffffffff8150080d>] print_address_description+0x6c/0x234 mm/kasan/report.c:256
 [<ffffffff81500c17>] kasan_report_error mm/kasan/report.c:355 [inline]
 [<ffffffff81500c17>] kasan_report.cold.6+0x242/0x2fe mm/kasan/report.c:412
 [<ffffffff814f2e24>] __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433
 [<ffffffff810ac4ff>] unwind_get_return_address+0x8f/0xa0 arch/x86/kernel/unwind_frame.c:17
 [<ffffffff8107796d>] __save_stack_trace+0x8d/0xf0 arch/x86/kernel/stacktrace.c:43
 [<ffffffff81077a38>] save_stack_trace_tsk+0x48/0x70 arch/x86/kernel/stacktrace.c:71
 [<ffffffff81665e78>] proc_pid_stack+0x148/0x220 fs/proc/base.c:469
 [<ffffffff8165e3fd>] proc_single_show+0xfd/0x170 fs/proc/base.c:771
 [<ffffffff815809d6>] seq_read+0x4b6/0x12d0 fs/seq_file.c:240
 [<ffffffff81509c45>] do_loop_readv_writev.part.1+0xd5/0x280 fs/read_write.c:718
 [<ffffffff8150c560>] do_loop_readv_writev fs/read_write.c:707 [inline]
 [<ffffffff8150c560>] compat_do_readv_writev+0x570/0x7b0 fs/read_write.c:1091
 [<ffffffff8150c882>] compat_readv+0xe2/0x150 fs/read_write.c:1120
 [<ffffffff8150cc12>] do_compat_preadv64+0x152/0x180 fs/read_write.c:1169
 [<ffffffff8150f19b>] C_SYSC_preadv fs/read_write.c:1189 [inline]
 [<ffffffff8150f19b>] compat_SyS_preadv+0x3b/0x50 fs/read_write.c:1183
 [<ffffffff81006311>] do_syscall_32_irqs_on arch/x86/entry/common.c:328 [inline]
 [<ffffffff81006311>] do_fast_syscall_32+0x2f1/0xa10 arch/x86/entry/common.c:390
 [<ffffffff82804560>] entry_SYSENTER_compat+0x90/0xa2 arch/x86/entry/entry_64_compat.S:137

The buggy address belongs to the page:
page:ffffea0006b76dc0 count:0 mapcount:0 mapping:          (null) index:0x0
flags: 0x4000000000000000()
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8801addb7c80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8801addb7d00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff8801addb7d80: f1 f1 f1 f1 00 f2 f2 f2 f2 f2 f2 f2 00 f2 f2 f2
                                                          ^
 ffff8801addb7e00: f2 f2 f2 f2 00 00 f2 f2 00 00 00 00 00 00 00 00
 ffff8801addb7e80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================