CVE-2025-68803: NFSD: NFSv4 file creation neglects setting ACL
In the Linux kernel, the following vulnerability has been resolved:
NFSD: NFSv4 file creation neglects setting ACL
An NFSv4 client that sets an ACL with a named principal during file creation retrieves the ACL afterwards, and finds that it is only a default ACL (based on the mode bits) and not the ACL that was requested during file creation. This violates RFC 8881 section 6.4.1.3: "the ACL attribute is set as given".
The issue occurs in nfsdcreatesetattr(), which calls nfsdattrsvalid() to determine whether to call nfsdsetattr(). However, nfsdattrsvalid() checks only for iattr changes and security labels, but not POSIX ACLs. When only an ACL is present, the function returns false, nfsdsetattr() is skipped, and the POSIX ACL is never applied to the inode.
Subsequently, when the client retrieves the ACL, the server finds no POSIX ACL on the inode and returns one generated from the file's mode bits rather than returning the originally-specified ACL.
Affected Software
Event History
Frequently Asked Questions
What is the severity of CVE-2025-68803?
CVE-2025-68803 has a high severity due to potential unauthorized access or modification of file permissions.
How do I fix CVE-2025-68803?
To fix CVE-2025-68803, update the Linux kernel to the latest stable version that addresses this vulnerability.
What systems are affected by CVE-2025-68803?
CVE-2025-68803 affects the Linux kernel specifically in configurations using NFSv4 file creation with ACLs.
What are the risks associated with CVE-2025-68803?
The risks of CVE-2025-68803 include improper enforcement of access controls, leading to potential security breaches.
Is there a workaround for CVE-2025-68803?
Currently, the only recommended mitigation for CVE-2025-68803 is to apply the kernel update as there are no effective workarounds.