CVE-2026-31458
Description
A flaw was found in the Linux kernel. A privileged local user can exploit this by manipulating the nr_contexts parameter in the mm/damon/sysfs interface to zero while the DAMON (Data Access MONitor) subsystem is active. This leads to a null pointer dereference when certain sysfs commands are subsequently executed, potentially causing a system crash and a Denial of Service (DoS).
Statement
Moderate: A null pointer dereference in the Linux kernel's DAMON subsystem can cause a system crash, leading to a Denial of Service. This vulnerability requires a privileged local attacker to enable DAMON and then specifically manipulate its sysfs interface. Red Hat Enterprise Linux 9 and 10, and Red Hat In-Vehicle OS are affected.
Mitigation
To mitigate this issue, avoid activating the DAMON (Data Access MONitor) subsystem if its functionality is not required. The vulnerability can only be exploited when DAMON is active, allowing a privileged local attacker to trigger a system crash by manipulating its sysfs interface.
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 | 5.5 | N/A |
| Attack Vector | Local | Local | N/A |
| Attack Complexity | Low | Low | N/A |
| Privileges Required | Low | Low | N/A |
| User Interaction | None | None | N/A |
| Scope | Unchanged | Unchanged | N/A |
| Confidentiality | None | None | N/A |
| Integrity Impact | None | None | N/A |
| Availability Impact | High | High | N/A |
Vector
Red Hat: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
NVD: 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: Crash, Exit, or Restart
NULL pointer dereferences usually result in the failure of the process unless exception handling (on some platforms) is available and implemented. Even when exception handling is being used, it can still be very difficult to return the software to a safe state of operation.
Integrity,Confidentiality
Technical Impact: Execute Unauthorized Code or Commands; Read Memory; Modify Memory
In rare circumstances, when NULL is equivalent to the 0x0 memory address and privileged code can access it, then writing or reading memory is possible, which may lead to code execution.
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