exfat: resolve memory leak from exfat_create_upcase_table()

Vulnerability Description

In the Linux kernel, the following vulnerability has been resolved: exfat: resolve memory leak from exfat_create_upcase_table() If exfat_load_upcase_table reaches end and returns -EINVAL, allocated memory doesn't get freed and while exfat_load_default_upcase_table allocates more memory, leading to a memory leak. Here's link to syzkaller crash report illustrating this issue: https://syzkaller.appspot.com/text?tag=CrashReport&x=1406c201980000

References

• https://git.kernel.org/stable/c/f9835aec49670c46ebe2973032caaa1043b3d4da
• https://git.kernel.org/stable/c/331ed2c739ce656a67865f6b3ee0a478349d78cb
• https://git.kernel.org/stable/c/c290fe508eee36df1640c3cb35dc8f89e073c8a8