CVE-2026-72368

Received Received - Intake

Double Unlock in Linux Kernel cachefiles

Publication date: 2026-08-15

Last updated on: 2026-08-17

Assigner: kernel.org

Description

In the Linux kernel, the following vulnerability has been resolved: cachefiles: Fix double unlock in nomem_d_alloc error path When start_creating() fails and returns -ENOMEM, it has already released the parent directory lock in __start_dirop(): static struct dentry *__start_dirop(...) { ... inode_lock_nested(dir, I_MUTEX_PARENT); dentry = lookup_one_qstr_excl(name, parent, lookup_flags); if (IS_ERR(dentry)) inode_unlock(dir); <-- Lock released on error return dentry; } However, the nomem_d_alloc error path in cachefiles_get_directory() unconditionally calls inode_unlock(d_inode(dir)) again, causing a double unlock that corrupts the rwsem state. This is a leftover from commit 7ab96df840e60 which replaced manual locking with start_creating() but failed to update the nomem_d_alloc path (while correctly updating mkdir_error and lookup_error paths).

CVSS Scores

EPSS Scores

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Meta Information

Published

2026-08-15

Last Modified

2026-08-17

Generated

2026-09-04

AI Q&A

2026-08-15

EPSS Evaluated

2026-09-03

NVD

CVE-2026-72368

EUVD

EUVD-2026-59267

Affected Vendors & Products

Vendor	Product	Version / Range
linux	linux_kernel	*

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-UNKNOWN

Attack-Flow Graph

Executive Summary

This is a Linux kernel vulnerability where a double unlock of a directory lock occurs in the cachefiles subsystem. When start_creating() fails with -ENOMEM, the parent directory lock is already released in __start_dirop(), but the nomem_d_alloc error path in cachefiles_get_directory() tries to unlock it again, corrupting the rwsem state.

Detection Guidance

This vulnerability is specific to the Linux kernel's cachefiles subsystem and does not have network-based detection methods. It can only be detected by checking the kernel version and examining the source code or running kernel-specific checks for the double unlock issue in cachefiles.

Impact Analysis

This vulnerability could lead to kernel memory corruption or crashes due to the corrupted rwsem state. It may cause system instability, data corruption, or denial of service if exploited.

Compliance Impact

This vulnerability does not directly affect compliance with standards like GDPR or HIPAA as it is a low-level kernel locking issue that could lead to system instability or crashes rather than data breaches or unauthorized access.

Mitigation Strategies

Apply the latest kernel patch that resolves this issue. If a patch is not available, avoid using the cachefiles feature until an update is applied. Monitor kernel security advisories for updates.

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