The Linux kernel's NFS server code for handling SETACL operations called the ACL decoding function twice, transferring ownership of allocated posix_acl objects. If the first call succeeded but the second failed, the decoder returned false, causing the main processing function to skip the release function that would free these objects. As a result, posix_acl objects were leaked for the lifetime of the server process. The fix involved adding dedicated release functions that free both ACL objects and wiring them to run on every code path after decoding, including failure paths, thus preventing the leak.

The vulnerability results in a memory leak of posix_acl structures on the NFS server when SETACL decode fails. This can lead to increased memory consumption and potential denial of service due to resource exhaustion. There is no direct impact on confidentiality or integrity. The CVSS score is 7.5 (high impact on availability).

A fix has been implemented in the Linux kernel to properly release posix_acl objects on all code paths after SETACL decoding, including failure cases. Users should apply the official kernel updates that include this fix. Since this is a kernel-level issue, upgrading to a patched kernel version from the vendor or distribution is the recommended remediation. Patch status is not explicitly stated here; check the vendor or distribution advisory for the exact fixed versions and update instructions.