CVE Database›Document archive›CVE-2026-74330

CVE-2026-74330

kernel: configfs: fix lockless traversals of ->s_children

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Severity

Moderate

Red Hat Product Security

5.5

CVSS 3.1

Review impact separately from score.

Published · August 15, 2026

Updated · October 17, 2026

Description

A flaw was found in the Linux kernel's configfs component. This vulnerability arises from improper handling of directory traversals, where cursors can be unexpectedly moved or freed by another process even when the parent directory is locked. This lack of proper synchronization can lead to an inconsistent system state, potentially causing system instability or data corruption.

Statement

A moderate impact flaw was found in the Linux kernel's configfs file system. When a configfs directory is read, the kernel traverses the ->s_children list of directory entries without adequate locking. Holding the parent directory's lock protects entries from being removed by another thread, but it does not protect the directory cursor entries used during such traversals from being moved around by lseek() or freed by another process. A local user able to access and operate on a configfs mount could race these operations to corrupt kernel memory, resulting in a system crash or inconsistent system state, which is primarily a denial of service. Red Hat assessed this flaw as Moderate severity (CVSS 3.1 score 5.5, AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H) because exploitation requires local access with privileges to interact with configfs and the realistic impact is limited to availability; this differs from the upstream CVE record's Important rating of 7.8, which assumes full confidentiality, integrity, and availability impact. The kernel and kernel-rt packages in Red Hat Enterprise Linux 7, 8, 9, and 10, and the kernel and kernel-ivos-qualcomm packages in Red Hat In-Vehicle OS 2, are affected, with fixes currently deferred: because this is a long-standing race condition whose practical impact is a local denial of service, the fix is planned to be delivered in a future scheduled maintenance update rather than as an immediate update. Until a fix is delivered, the residual risk is that a local attacker with access to configfs could trigger the race and crash the system. The Red Hat Enterprise Linux 6 stream is out of support scope and is not scheduled to receive a fix.

CVSS score applicability

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

Mitigation

Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.

CVSS / CWE

CVSS 3.1 · 5.5
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

CWE-367 · Time-of-check Time-of-use (TOCTOU) Race Condition