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BUG: KASAN: global-out-of-bounds in strscpy+0x20e/0x2c0 lib/string.c:206
Read of size 8 at addr ffffffff8677d6f8 by task syz-executor.1/8086

CPU: 0 PID: 8086 Comm: syz-executor.1 Not tainted 4.14.113 #3
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x138/0x19c lib/dump_stack.c:53
 print_address_description.cold+0x5/0x1dc mm/kasan/report.c:252
FAT-fs (loop0): bogus number of directory entries (515)
 kasan_report_error mm/kasan/report.c:351 [inline]
 kasan_report mm/kasan/report.c:409 [inline]
 kasan_report.cold+0xaf/0x2b5 mm/kasan/report.c:393
 __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:430
 strscpy+0x20e/0x2c0 lib/string.c:206
 prepare_error_buf+0x94/0x1aa0 fs/reiserfs/prints.c:213
FAT-fs (loop0): Can't find a valid FAT filesystem
 __reiserfs_warning+0x9f/0xb0 fs/reiserfs/prints.c:288
 reiserfs_fill_super+0xa71/0x2b20 fs/reiserfs/super.c:1980
 mount_bdev+0x2c1/0x370 fs/super.c:1134
 get_super_block+0x35/0x40 fs/reiserfs/super.c:2605
 mount_fs+0x9d/0x2a7 fs/super.c:1237
 vfs_kern_mount.part.0+0x5e/0x3d0 fs/namespace.c:1046
 vfs_kern_mount fs/namespace.c:1036 [inline]
 do_new_mount fs/namespace.c:2549 [inline]
 do_mount+0x417/0x27d0 fs/namespace.c:2879
 SYSC_mount fs/namespace.c:3095 [inline]
 SyS_mount+0xab/0x120 fs/namespace.c:3072
 do_syscall_64+0x1eb/0x630 arch/x86/entry/common.c:289
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x45b69a
RSP: 002b:00007faa05d44a88 EFLAGS: 00000206 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007faa05d44b40 RCX: 000000000045b69a
RDX: 00007faa05d44ae0 RSI: 0000000020000200 RDI: 00007faa05d44b00
RBP: 0000000000000000 R08: 00007faa05d44b40 R09: 00007faa05d44ae0
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000004
R13: 00000000004c782d R14: 00000000004dd880 R15: 00000000ffffffff

The buggy address belongs to the variable:
 __func__.31266+0x2dd8/0x3a60

Memory state around the buggy address:
 ffffffff8677d580: 01 fa fa fa fa fa fa fa 01 fa fa fa fa fa fa fa
 ffffffff8677d600: 00 00 00 00 00 07 fa fa fa fa fa fa 00 00 00 07
>ffffffff8677d680: fa fa fa fa 00 fa fa fa fa fa fa fa 00 00 00 04
                                                                ^
 ffffffff8677d700: fa fa fa fa 00 fa fa fa fa fa fa fa 00 00 00 00
 ffffffff8677d780: 00 00 00 00 02 fa fa fa fa fa fa fa 00 00 00 00
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