Linux Kernel exFAT Double Free Vulnerability in Upcase Table Management

A double free vulnerability has been identified in the Linux kernel's exFAT file system implementation. This issue arises during the management of the upcase table, which is used for file name case mapping. The vulnerability occurs when the function exfat_create_upcase_table() encounters an error and returns, leading to the exfat_free_upcase_table() function being called to free the upcase table. However, if exfat_load_default_upcase_table() also returns an error, the upcase table is freed again, resulting in a double free condition. The vulnerability has been addressed by modifying the code to set the upcase table pointer to NULL after it has been freed, preventing the double free from occurring.

Impact

Exploitation of this vulnerability could lead to memory corruption issues, commonly associated with double free vulnerabilities, which can be exploited to execute arbitrary code or cause a denial-of-service condition by crashing the system.