Linux Kernel AppArmor Memory Leak Vulnerability in aa_simple_write_to_buffer

A memory leak vulnerability has been identified in the Linux kernel's AppArmor subsystem, specifically within the aa_simple_write_to_buffer() function. The issue arises when the copy_from_user function fails; while the memory is released using kvfree, the management structure and data blob are allocated separately. This discrepancy leads to a memory leak, as only the data blob is properly freed. The vulnerability has been addressed by modifying the memory management to use aa_put_loaddata(data), ensuring that all allocated resources are correctly released.

Impact

Exploitation of this vulnerability leads to a memory leak, where allocated memory is not properly freed, potentially causing increased memory usage and degradation of system performance over time.