CVE-2026-68312

Received Received - Intake

Memory Leak in Linux Kernel CIFS Module

Publication date: 2026-08-10

Last updated on: 2026-08-17

Assigner: kernel.org

Description

In the Linux kernel, the following vulnerability has been resolved: cifs: fix cifsFileInfo leak on kmalloc failure in deferred close drain paths In cifs_close_deferred_file(), cifs_close_all_deferred_files(), and cifs_close_deferred_file_under_dentry(), when a pending deferred close is cancelled via cancel_delayed_work(), the subsequent kmalloc_obj() to add the file to the local processing list may fail under memory pressure. The loop breaks immediately, but the cancelled work is no longer pending (it would have called _cifsFileInfo_put()), and the cfile is never added to file_head for processing. The cifsFileInfo reference and the open server handle both leak. Fix by saving the cfile that failed allocation in a local variable, breaking as before, and calling _cifsFileInfo_put() on it after releasing the lock. Any files later in the iteration are unaffected since their deferred work is still pending and will fire normally.

CVSS Scores

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Meta Information

Published

2026-08-10

Last Modified

2026-08-17

Generated

2026-08-30

AI Q&A

2026-08-10

EPSS Evaluated

2026-08-29

NVD

CVE-2026-68312

EUVD

EUVD-2026-55413

Affected Vendors & Products

Vendor	Product	Version / Range
linux_kernel	cifs	*

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-UNKNOWN

Attack-Flow Graph

Executive Summary

This vulnerability in the Linux kernel involves a memory leak in the CIFS (Common Internet File System) module. When a deferred file close operation is cancelled due to memory allocation failure, the system fails to properly release a reference to the file, causing both the file reference and server handle to leak.

Detection Guidance

This vulnerability is specific to the Linux kernel's CIFS (Common Internet File System) module and involves a memory leak in deferred file close operations. Detection requires checking kernel logs for memory leaks or errors related to cifsFileInfo or deferred close operations. Commands like dmesg | grep cifs or journalctl -k | grep cifs may help identify related errors.

Impact Analysis

This vulnerability could lead to resource exhaustion on systems using CIFS, potentially causing performance degradation or crashes due to unreleased file handles and memory leaks. It may affect systems under heavy memory pressure.

Compliance Impact

This vulnerability causes resource leaks in the Linux kernel's CIFS module, specifically cifsFileInfo and server handles. While it does not directly impact data confidentiality or integrity, resource leaks can lead to system instability or crashes under memory pressure. This may indirectly affect compliance by causing service disruptions or data processing delays, which could violate availability requirements in standards like GDPR or HIPAA.

Mitigation Strategies

Apply the latest Linux kernel update that includes the fix for this CVE. Monitor system memory usage and kernel logs for signs of cifsFileInfo leaks. If immediate patching is not possible, consider reducing memory pressure on the system to minimize the risk of kmalloc_obj() failures.

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