Linux Kernel ksmbd Reference Count Leak Vulnerability in smb_check_perm_dacl

A reference count leak vulnerability has been identified in the Linux kernel's ksmbd component, specifically within the smb_check_perm_dacl() function. The issue arises when the 'id' and 'uid' values are identical, causing the function to exit the loop without properly decrementing the reference count of the 'posix_acls' object. This object’s reference count is initially increased by the get_acl() function, leading to potential memory leaks. The vulnerability has been addressed by ensuring the reference count of 'posix_acls' is decreased before the function exits the loop.

Impact

Exploitation of this vulnerability can lead to memory leaks, causing increased memory usage and potentially degrading system performance over time.