CVE-2024-49870

Name of the Vulnerable Software and Affected Versions: Linux kernel versions prior to 6.6.58

Description: A dentry leak may occur in the Linux kernel when a lookup cookie and a cull are concurrent. This happens because the reference count obtained by lookup one positive unlocked() in cachefiles look up object() is not released. As a result, a WARNING is triggered when the backend folder is umounted, indicating that a dentry is still in use.

Recommendations: To resolve this issue, update to Linux kernel version 6.6.58 or later. As a temporary workaround, consider disabling the cachefiles open file() function until a patch is available. Restrict access to the vulnerable cachefiles module to minimize the risk of exploitation. Avoid using the lookup one positive unlocked() function in the affected cachefiles look up object() function until the issue is resolved.