In the Linux kernel, a vulnerability has been identified related to the handling of memory allocation errors in the fec_enet_update_cbd function. This function calls page_pool_dev_alloc_pages, which may return NULL. If this occurs, the driver does not handle the NULL pointer correctly, leading to system crashes, particularly under memory pressure scenarios. This situation can arise when writing to a smbd share on a SATA HDD attached to an imx6q.
The vulnerability is classified as medium severity with a CVSS score of 5.5. It is essential for organizations using affected Linux kernel versions to prioritize remediation. If not addressed, the risk includes potential system instability and service interruptions.
Organizations should prioritize patching immediately to mitigate the associated risks. The vulnerability can result in significant operational disruptions, particularly in environments under heavy memory usage.
The vulnerability has not been actively exploited in the wild, but given its nature, defenders should remain vigilant. Patching is the recommended course of action to ensure system stability and integrity.
Vulnerability Details
The vulnerability identified as CVE-2025-21676 allows for a memory allocation error that can lead to a crash in the Linux kernel. The issue was first published on January 31, 2025. The CVSS score of 5.5 indicates a medium severity classification, with the primary impact being a potential denial of service due to unhandled NULL pointers during memory allocation.
The affected product is the Linux kernel, specifically versions from 6.1 to 6.12.10 and various release candidates of version 6.13.
The vulnerability is classified under CWE-476, which pertains to NULL Pointer Dereference.
Technical Analysis
The root cause of this vulnerability lies in the failure to handle NULL pointers returned by the page_pool_dev_alloc_pages function. When the memory allocation fails, the fec driver does not appropriately manage this situation, leading to potential system crashes.
The attack vector is local, requiring low privileges to exploit. The complexity of the attack is also low, as it does not require user interaction. The availability impact is classified as high, indicating that the system may become unavailable due to crashes.
Risk & Impact Analysis
Risk to organizations includes potential system crashes and data loss due to unhandled memory allocation errors. The impact is magnified in environments with limited memory resources, leading to operational disruptions and degraded performance.
Given the CVSS score of 5.5, organizations should address this vulnerability in their priority patch cycle. The urgency is underscored by the potential for significant service interruptions.
Exploitation Status
Signal | Status |
|---|---|
Known Exploit | No |
Public PoC | No |
Actively Exploited | No |
Ransomware Use | No |
Affected Versions
The following versions of the Linux kernel are affected by this vulnerability: Versions 6.1 through 6.6.74, and versions 6.7 through 6.12.10, as well as release candidates 6.13: rc1 through rc7.
Mitigation & Remediation
Organizations are advised to patch their systems to the latest version of the Linux kernel as soon as possible to mitigate this vulnerability. For those unable to apply patches immediately, consider adjusting memory management settings, such as increasing the min_free_kbytes parameter in /proc/sys/vm, which can alleviate some symptoms of the issue.
For further assistance, organizations can utilize our penetration testing services to identify potential weaknesses.
Detection Guidance
To detect potential exploitation of this vulnerability, organizations should monitor system logs for unusual error messages related to memory allocation failures. Additionally, monitor performance metrics for sudden drops in availability or unexpected crashes.
AppSecure Threat Intelligence Insight
The long-term significance of CVE-2025-21676 indicates a pattern of vulnerabilities related to memory management in kernel drivers, which can be prevalent across various platforms. Security teams should focus on strengthening memory allocation practices and testing under scenarios of constrained resources.
Organizations are encouraged to engage in proactive security measures by implementing a comprehensive vulnerability management program to effectively identify and remediate similar vulnerabilities in the future.
In conclusion, security teams should remain vigilant and adapt their defenses to address potential threats emerging from kernel vulnerabilities by leveraging penetration testing methodologies to identify and remediate weaknesses before they can be exploited.
Organizations should also consider the broader implications of vulnerabilities like CVE-2025-21676 on their overall security posture and the importance of maintaining up-to-date systems.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
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