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BUG: KASAN: stack-out-of-bounds in get_frame_pointer arch/x86/include/asm/stacktrace.h:64 [inline]
BUG: KASAN: stack-out-of-bounds in __unwind_start+0x37c/0x3c0 arch/x86/kernel/unwind_frame.c:76
Read of size 8 at addr ffff8801a26779f8 by task syz-executor6/7628

CPU: 1 PID: 7628 Comm: syz-executor6 Not tainted 4.9.123-g520d10d3 #81
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 ffff8801a1837770 ffffffff81eb9689 ffffea0006899dc0 ffff8801a26779f8
 0000000000000000 ffff8801a26779f8 ffff8801a18378a8 ffff8801a18377a8
 ffffffff8156c3fe ffff8801a26779f8 0000000000000008 0000000000000000
Call Trace:
 [<ffffffff81eb9689>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81eb9689>] dump_stack+0xc1/0x128 lib/dump_stack.c:51
 [<ffffffff8156c3fe>] print_address_description+0x6c/0x234 mm/kasan/report.c:256
 [<ffffffff8156c808>] kasan_report_error mm/kasan/report.c:355 [inline]
 [<ffffffff8156c808>] kasan_report.cold.6+0x242/0x2fe mm/kasan/report.c:412
 [<ffffffff8153fb94>] __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433
 [<ffffffff810d42dc>] get_frame_pointer arch/x86/include/asm/stacktrace.h:64 [inline]
 [<ffffffff810d42dc>] __unwind_start+0x37c/0x3c0 arch/x86/kernel/unwind_frame.c:76
 [<ffffffff8107b9a9>] unwind_start arch/x86/include/asm/unwind.h:39 [inline]
 [<ffffffff8107b9a9>] __save_stack_trace+0x59/0xf0 arch/x86/kernel/stacktrace.c:41
 [<ffffffff8107baa8>] save_stack_trace_tsk+0x48/0x70 arch/x86/kernel/stacktrace.c:71
 [<ffffffff816dc3d8>] proc_pid_stack+0x148/0x220 fs/proc/base.c:469
 [<ffffffff816ddacd>] proc_single_show+0xfd/0x170 fs/proc/base.c:771
 [<ffffffff815f1c56>] seq_read+0x4b6/0x12e0 fs/seq_file.c:240
 [<ffffffff81573c95>] do_loop_readv_writev.part.18+0xd5/0x280 fs/read_write.c:718
 [<ffffffff81577be5>] do_loop_readv_writev fs/read_write.c:707 [inline]
 [<ffffffff81577be5>] do_readv_writev+0x565/0x7a0 fs/read_write.c:873
 [<ffffffff81577ea4>] vfs_readv+0x84/0xc0 fs/read_write.c:897
 [<ffffffff815782d7>] do_preadv+0x197/0x240 fs/read_write.c:974
 [<ffffffff8157b890>] SYSC_preadv fs/read_write.c:1024 [inline]
 [<ffffffff8157b890>] SyS_preadv+0x30/0x40 fs/read_write.c:1019
 [<ffffffff81006316>] do_syscall_64+0x1a6/0x490 arch/x86/entry/common.c:282
 [<ffffffff83a01d93>] entry_SYSCALL_64_after_swapgs+0x5d/0xdb

The buggy address belongs to the page:
page:ffffea0006899dc0 count:0 mapcount:0 mapping:          (null) index:0x0
flags: 0x8000000000000000()
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8801a2677880: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8801a2677900: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff8801a2677980: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
                                                                ^
 ffff8801a2677a00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8801a2677a80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
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IPVS: Creating netns size=2536 id=19