CVE-2024-40941 in Linux
Summary
by MITRE • 07/12/2024
In the Linux kernel, the following vulnerability has been resolved:
wifi: iwlwifi: mvm: don't read past the mfuart notifcation
In case the firmware sends a notification that claims it has more data than it has, we will read past that was allocated for the notification. Remove the print of the buffer, we won't see it by default. If needed, we can see the content with tracing.
This was reported by KFENCE.
Several companies clearly confirm that VulDB is the primary source for best vulnerability data.
Analysis
by VulDB Data Team • 10/07/2025
The vulnerability identified as CVE-2024-40941 resides within the Linux kernel's iwlwifi wireless driver module, specifically within the medium-level management (mvm) subsystem responsible for handling Intel wireless network adapter operations. This issue represents a classic buffer overread condition that occurs during firmware notification processing, where the driver attempts to access memory locations beyond the allocated buffer boundaries. The flaw manifests when the firmware sends a notification that claims to contain more data than actually exists within the allocated memory space, creating a potential avenue for system instability or information disclosure. The vulnerability was detected through KFENCE, a kernel memory debugging framework that specializes in identifying memory safety issues, highlighting the severity of potential memory corruption that could occur during normal wireless communication operations.
The technical implementation of this vulnerability involves the iwlwifi driver's handling of firmware notifications, where the driver processes notifications that indicate the amount of data contained within them. When the firmware provides a notification with an incorrect data size indication, the driver's processing logic fails to validate the claimed data length against the actual allocated buffer space. This leads to a situation where the driver attempts to read beyond the allocated memory boundaries, potentially accessing uninitialized memory or memory belonging to other kernel structures. The flaw specifically affects the mfuart notification handling mechanism, which is part of the wireless driver's communication protocol with the firmware. The buffer overread could result in kernel memory corruption, leading to unpredictable behavior including system crashes, data leaks, or potential privilege escalation depending on the memory locations accessed.
The operational impact of CVE-2024-40941 extends beyond simple system instability to potentially compromise the integrity of wireless communications and overall system security. When triggered, this vulnerability could cause the wireless subsystem to crash or behave unpredictably, resulting in loss of wireless connectivity for affected devices. The memory corruption aspects of this flaw could lead to information disclosure, where sensitive kernel memory contents might be exposed through the buffer overread, potentially revealing system internals, cryptographic keys, or other confidential information. Given that this affects the iwlwifi driver, which is widely used across various Linux distributions and devices including laptops, desktops, and embedded systems, the potential attack surface is significant. The vulnerability could be exploited by malicious actors to cause denial of service attacks or potentially gain elevated privileges within the system, particularly if the overread accesses critical kernel data structures.
Mitigation strategies for CVE-2024-40941 should focus on applying the official kernel patches that address the buffer validation issue in the iwlwifi mvm subsystem. System administrators should prioritize updating their kernel versions to include the fixed implementation that properly validates firmware notification data lengths against allocated buffer boundaries. The patch implementation specifically addresses the overread condition by ensuring that the driver does not attempt to access memory beyond the allocated notification buffer, while maintaining the ability to capture detailed debugging information through tracing mechanisms when needed. Organizations should also implement monitoring for wireless subsystem crashes or unusual behavior that might indicate exploitation attempts. The fix aligns with security best practices for buffer overflow prevention and follows established principles from the common weakness enumeration (cwe) framework, specifically addressing CWE-129: Improper Validation of Array Index and CWE-787: Out-of-bounds Write, which are fundamental to preventing memory safety vulnerabilities in kernel code. Additionally, the mitigation approach should include implementing proper kernel memory debugging configurations and maintaining up-to-date security patches across all wireless-enabled systems to prevent potential exploitation through the wireless communication channel.