CVE Catalog

CVE-2025-71090

HighCVSS 7.5
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.18%

8th percentile - higher than 8% of all known CVEs

Summary

In the NFS server (nfsd), an nfsd_file reference leak was found in nfsd4_add_rdaccess_to_wrdeleg(). Overwriting a pointer without releasing the previous one and improper reference management leads to memory leaks and potential file open conflicts. During server shutdown, a BUG() in kmem_cache_destroy() may occur.

Risk Assessment

Memory leaks can lead to resource exhaustion, and file open conflicts may prevent file access. A crash during server shutdown causes denial of service.

Recommendation

It is recommended to update the Linux kernel to a version containing the fix.

Other vulnerabilities in Linux kernel

See all
Original NVD description (English source)

In the Linux kernel, the following vulnerability has been resolved: nfsd: fix nfsd_file reference leak in nfsd4_add_rdaccess_to_wrdeleg() nfsd4_add_rdaccess_to_wrdeleg() unconditionally overwrites fp->fi_fds[O_RDONLY] with a newly acquired nfsd_file. However, if the client already has a SHARE_ACCESS_READ open from a previous OPEN operation, this action overwrites the existing pointer without releasing its reference, orphaning the previous reference. Additionally, the function originally stored the same nfsd_file pointer in both fp->fi_fds[O_RDONLY] and fp->fi_rdeleg_file with only a single reference. When put_deleg_file() runs, it clears fi_rdeleg_file and calls nfs4_file_put_access() to release the file. However, nfs4_file_put_access() only releases fi_fds[O_RDONLY] when the fi_access[O_RDONLY] counter drops to zero. If another READ open exists on the file, the counter remains elevated and the nfsd_file reference from the delegation is never released. This potentially causes open conflicts on that file. Then, on server shutdown, these leaks cause __nfsd_file_cache_purge() to encounter files with an elevated reference count that cannot be cleaned up, ultimately triggering a BUG() in kmem_cache_destroy() because there are still nfsd_file objects allocated in that cache.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS