CVE-2022-48988

Name of the Vulnerable Software and Affected Versions Linux kernel versions prior to 347c4a874710

Description The issue is related to a possible use-after-free in the memcg write event control() function. This function accesses the dentry->d name of the specified control file descriptor to route the write call. Prior to a specific commit, there was a call to file cft() that verified the file type before further accesses. However, this check was inadvertently dropped, allowing any file to be accessed and potentially causing use-after-free issues. The vulnerability may allow an attacker to impact the confidentiality, integrity, and availability of protected information.

Recommendations To resolve the issue, apply the fix that resurrects the file type check in file cft(). This can be done by checking the superblock and dentry type, as the cgroupfs is now implemented through kernfs. For Linux kernel versions prior to 347c4a874710, update to a version that includes the fix for the memcg write event control() function.