CVE-2026-98388
Description
A flaw was found in the Linux kernel. During program execution, the kernel closes file descriptors marked for close-on-exec while holding an internal process state lock. If closing a file descriptor stalls on an unresponsive or user-space filesystem, the lock remains held and blocks related system operations. A local attacker can exploit this behavior to trigger a deadlock, resulting in a Denial of Service (DoS).
Statement
A low impact denial of service flaw was found in the Linux kernel as shipped in Red Hat offerings. During program execution, the kernel closes file descriptors marked for close-on-exec (do_close_on_exec()) while holding exec_update_lock, a lock that is used in many places that access process state to synchronize access checks. Closing a file descriptor can block waiting for a reply from a filesystem, so a hung or unresponsive filesystem keeps the lock held and blocks kernel code paths that use exec_update_lock; a FUSE filesystem whose daemon attempts to inspect the calling process can also deadlock. A local unprivileged attacker can exploit this behavior by triggering program execution with a close-on-exec file descriptor backed by such a filesystem, hanging process execution and related process-state operations and causing a local denial of service. There is no impact on confidentiality or integrity. The Red Hat CVSS:3.1 base score is 5.5 (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H); while that base score maps to Moderate, Red Hat Product Security assesses the overall impact of this flaw as LOW because exploitation requires local access with a prepared close-on-exec file descriptor on a suitable blocking filesystem and the result is limited to a local denial of service. Of the Red Hat products in scope, only the kernel in the Red Hat Enterprise Linux 6 Extended Lifecycle Support stream is listed as affected, and that stream is out of support scope so no fix is planned for it. The kernels in Red Hat Enterprise Linux 7, 8, 9, and 10 (including the kernel-rt variant), the Red Hat In-Vehicle OS kernels, and the Red Hat Enterprise Linux CoreOS images shipped with OpenShift Container Platform are not affected because the vulnerable code is not present in those kernels.
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.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 5.5 | N/A | N/A |
| Attack Vector | Local | N/A | N/A |
| Attack Complexity | Low | N/A | N/A |
| Privileges Required | Low | N/A | N/A |
| User Interaction | None | N/A | N/A |
| Scope | Unchanged | N/A | N/A |
| Confidentiality | None | N/A | N/A |
| Integrity Impact | None | N/A | N/A |
| Availability Impact | High | N/A | N/A |
Vector
Red Hat: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Understanding the Weakness (CWE)
Availability
Technical Impact: DoS: Resource Consumption (CPU); DoS: Resource Consumption (Other); DoS: Crash, Exit, or Restart
Each thread of execution will "hang" and prevent tasks from completing. In some cases, CPU consumption may occur if a lock check occurs in a tight loop.
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