Cybersecurity Vulnerabilities

CVE-2025-40252: Linux Kernel QEDE Driver Vulnerable to Out-of-Bounds Read

Overview

CVE-2025-40252 identifies a security vulnerability in the QLogic QEDE (QLogic Ethernet Driver) driver within the Linux kernel. This vulnerability stems from a potential out-of-bounds read issue within the qede_tpa_cont() and qede_tpa_end() functions. Improper bounds checking during iteration over a fixed-size array could lead to memory access beyond the intended boundaries, potentially causing system instability or information disclosure.

Technical Details

The vulnerability lies in the loops within the qede_tpa_cont() and qede_tpa_end() functions. These loops iterate over the cqe->len_list[] array. The original code relied solely on a zero-length terminator within the array to signal the end of the data. If this terminator was missing or malformed, the loops could potentially continue iterating past the end of the fixed-size array, leading to an out-of-bounds read. The fix introduces explicit bound checks using ARRAY_SIZE() in both loops to ensure the iteration remains within the valid bounds of the array.

The Linux Verification Center (LVC) with SVACE discovered this flaw.

CVSS Analysis

Currently, a CVSS score is not available (N/A) for CVE-2025-40252. This may be due to the specific conditions required to trigger the vulnerability and the difficulty in quantifying its potential impact. Further analysis and exploitation attempts might be needed to assign a more precise CVSS score.

Possible Impact

While the CVSS score is currently unavailable, the potential impact of an out-of-bounds read vulnerability can be significant. An attacker who can trigger this vulnerability could potentially:

  • Cause a kernel crash, leading to a denial-of-service (DoS) condition.
  • Read sensitive information from kernel memory, potentially exposing system secrets or other sensitive data.
  • In some scenarios, an out-of-bounds read could be leveraged in conjunction with other vulnerabilities for more severe attacks, such as privilege escalation.

Mitigation and Patch Steps

The vulnerability is resolved by applying the patches referenced below. Users of the Linux kernel are strongly advised to update to a kernel version containing these fixes. Specific kernel versions containing the fix can be determined by reviewing the commit history on the kernel.org git repository.

To mitigate the vulnerability, apply the following patches:

  1. Upgrade to a kernel version containing the fix.
  2. If upgrading is not immediately possible, consider disabling the QLogic QEDE driver if it is not essential for your system’s operation. This should only be done after careful consideration of the potential impact on your system’s functionality.

References

Cybersecurity specialist and founder of Gowri Shankar Infosec - a professional blog dedicated to sharing actionable insights on cybersecurity, data protection, server administration, and compliance frameworks including SOC 2, PCI DSS, and GDPR.

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