CVE-2025-71090
Unknown Unknown - Not Provided
BaseFortify

Publication date: 2026-01-13

Last updated on: 2026-03-25

Assigner: kernel.org

Description
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.
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Meta Information
Published
2026-01-13
Last Modified
2026-03-25
Generated
2026-05-06
AI Q&A
2026-01-14
EPSS Evaluated
2026-05-05
NVD
CVE-2025-71090
EUVD
EUVD-2026-2246
Affected Vendors & Products
Showing 10 associated CPEs
Vendor Product Version / Range
linux linux_kernel 6.19
linux linux_kernel 6.19
linux linux_kernel 6.19
linux linux_kernel 6.19
linux linux_kernel 6.19
linux linux_kernel 6.19
linux linux_kernel 6.19
linux linux_kernel 6.19
linux linux_kernel 6.17
linux linux_kernel From 6.17.1 (inc) to 6.18.4 (exc)
Helpful Resources
Exploitability
CWE
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KEV
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CWE ID Description
CWE-UNKNOWN
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AI Powered Q&A
Can you explain this vulnerability to me?

This vulnerability is a reference leak in the Linux kernel's NFS server code, specifically in the function nfsd4_add_rdaccess_to_wrdeleg(). The function overwrites a file pointer without releasing the previous reference if the client already has a read access open, causing the previous reference to be orphaned. Additionally, the same file pointer is stored in two places with only a single reference, leading to situations where the reference count does not decrease properly. This causes file references to remain elevated, potentially leading to open conflicts and problems during server shutdown when the system tries to clean up these references but cannot, resulting in a kernel bug.


How can this vulnerability impact me? :

This vulnerability can cause resource leaks in the NFS server, leading to open file conflicts and instability. During server shutdown, the elevated reference counts can prevent proper cleanup of file objects, triggering kernel bugs that may cause crashes or other unexpected behavior, potentially affecting system reliability and availability.


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