exfat: fix handling of damaged volume in exfat_create_upcase_table()

In the Linux kernel, the following vulnerability has been resolved: exfat: fix handling of damaged volume in exfat_create_upcase_table() When the size of the upcase table is set to zero in the dentry for any reason(e.g. corrupted media or misbehaving device), an integer overflow causes the module to loop indefinitely. If the size of the upcase table is read zero, do not attempt to load the table. Instead, fallback to loading the default upcase table. If the size of the upcase table is zero or no upcase table is found, raise exfat_fs_error() to mark the volume read-only.

Where it's fixed