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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+0x3a7/0x3c0 arch/x86/kernel/unwind_frame.c:76
Read of size 8 at addr ffff8801cf1cf308 by task syz-executor6/32459

CPU: 1 PID: 32459 Comm: syz-executor6 Not tainted 4.9.77-ge12a9c4 #18
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 ffff8801d0cc71a8 ffffffff81d941c9 ffffea00073c73c0 ffff8801cf1cf308
 0000000000000000 ffff8801cf1cf308 ffff8801d0cc72d8 ffff8801d0cc71e0
 ffffffff8153db93 ffff8801cf1cf308 0000000000000008 0000000000000000
Call Trace:
 [<ffffffff81d941c9>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81d941c9>] dump_stack+0xc1/0x128 lib/dump_stack.c:51
 [<ffffffff8153db93>] print_address_description+0x73/0x280 mm/kasan/report.c:252
 [<ffffffff8153e0b5>] kasan_report_error mm/kasan/report.c:351 [inline]
 [<ffffffff8153e0b5>] kasan_report+0x275/0x360 mm/kasan/report.c:408
 [<ffffffff8153e214>] __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:429
 [<ffffffff810d5397>] get_frame_pointer arch/x86/include/asm/stacktrace.h:64 [inline]
 [<ffffffff810d5397>] __unwind_start+0x3a7/0x3c0 arch/x86/kernel/unwind_frame.c:76
 [<ffffffff8107c689>] unwind_start arch/x86/include/asm/unwind.h:39 [inline]
 [<ffffffff8107c689>] __save_stack_trace+0x59/0xf0 arch/x86/kernel/stacktrace.c:41
 [<ffffffff8107c788>] save_stack_trace_tsk+0x48/0x70 arch/x86/kernel/stacktrace.c:71
 [<ffffffff816c4f46>] proc_pid_stack+0x146/0x230 fs/proc/base.c:466
 [<ffffffff816c6718>] proc_single_show+0xf8/0x170 fs/proc/base.c:768
 [<ffffffff815e884f>] seq_read+0x32f/0x1290 fs/seq_file.c:240
 [<ffffffff8156c5c1>] do_loop_readv_writev.part.17+0x141/0x1e0 fs/read_write.c:714
 [<ffffffff81570430>] do_loop_readv_writev fs/read_write.c:880 [inline]
 [<ffffffff81570430>] do_readv_writev+0x520/0x750 fs/read_write.c:874
 [<ffffffff815706e4>] vfs_readv+0x84/0xc0 fs/read_write.c:898
 [<ffffffff8160f79f>] kernel_readv fs/splice.c:363 [inline]
 [<ffffffff8160f79f>] default_file_splice_read+0x43f/0x7a0 fs/splice.c:435
 [<ffffffff8160e89a>] do_splice_to+0x10a/0x160 fs/splice.c:899
 [<ffffffff8160eb3d>] splice_direct_to_actor+0x24d/0x800 fs/splice.c:971
 [<ffffffff8160f297>] do_splice_direct+0x1a7/0x270 fs/splice.c:1080
 [<ffffffff815724ab>] do_sendfile+0x54b/0xd30 fs/read_write.c:1401
 [<ffffffff81574401>] SYSC_sendfile64 fs/read_write.c:1456 [inline]
 [<ffffffff81574401>] SyS_sendfile64+0xd1/0x160 fs/read_write.c:1448
 [<ffffffff838b2c2e>] entry_SYSCALL_64_fastpath+0x29/0xe8

The buggy address belongs to the page:
page:ffffea00073c73c0 count:0 mapcount:0 mapping:          (null) index:0x0
flags: 0x8000000000000000()
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8801cf1cf200: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8801cf1cf280: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 f1
>ffff8801cf1cf300: f1 f1 f1 04 f2 f2 f2 f2 f2 f2 f2 00 00 00 00 00
                      ^
 ffff8801cf1cf380: 04 f2 f2 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8801cf1cf400: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
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