CVE-2026-80622
Description
A flaw was found in the Linux kernel's tlclk driver. This vulnerability occurs due to improper module cleanup, where the driver can be unloaded while user-space processes are still active, and memory is freed prematurely. This can lead to a use-after-free condition and race conditions. A local attacker could potentially exploit this to cause a denial of service or achieve privilege escalation.
Statement
A moderate use-after-free vulnerability was found in the Linux kernel tlclk driver, affecting 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. The tlclk driver's file_operations structure did not set the .owner field, which allowed the module to be unloaded while user-space processes were still interacting with the device, and tlclk_cleanup() freed the alarm_events memory before all processes blocked on the waitqueue were awakened and before the switchover timer had completed. A local attacker able to access the tlclk device could exploit this race condition during module unload to cause a kernel panic, resulting in a denial of service. Red Hat rated this flaw Moderate (CVSS 5.5) because the demonstrated impact is limited to availability and reliably triggering the race is complex; this is lower than the upstream Important rating (CVSS 7.8), which assumes full confidentiality and integrity impact. Fixes for the affected Red Hat Enterprise Linux and Red Hat In-Vehicle OS streams are currently deferred, leaving a residual risk of local denial of service on systems where the tlclk module is loaded and unloaded while in use. The Red Hat Enterprise Linux 6 stream is out of support (OOSS) and is not scheduled to receive a fix.
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 | 7.8 |
| Attack Vector | Local | N/A | Local |
| Attack Complexity | Low | N/A | Low |
| Privileges Required | Low | N/A | Low |
| User Interaction | None | N/A | None |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | None | N/A | High |
| Integrity Impact | None | N/A | High |
| Availability Impact | High | N/A | High |
Vector
Red Hat: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
cve.org: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Understanding the Weakness (CWE)
Integrity,Other
Technical Impact: Alter Execution Logic; Unexpected State
The attacker can gain access to otherwise unauthorized resources.
Integrity,Other
Technical Impact: Modify Application Data; Modify Files or Directories; Modify Memory; Other
Race conditions such as this kind may be employed to gain read or write access to resources which are not normally readable or writable by the user in question.
Integrity,Other
Technical Impact: Other
The resource in question, or other resources (through the corrupted one), may be changed in undesirable ways by a malicious user.
Non-Repudiation
Technical Impact: Hide Activities
If a file or other resource is written in this method, as opposed to in a valid way, logging of the activity may not occur.
Non-Repudiation,Other
Technical Impact: Other
In some cases it may be possible to delete files a malicious user might not otherwise have access to, such as log files.
Other
Technical Impact: Unexpected State
The product may perform invalid actions when the resource is in an unexpected state.
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