CVE-2023-52841 in Linux
Summary
by MITRE • 05/21/2024
In the Linux kernel, the following vulnerability has been resolved:
media: vidtv: mux: Add check and kfree for kstrdup
Add check for the return value of kstrdup() and return the error if it fails in order to avoid NULL pointer dereference. Moreover, use kfree() in the later error handling in order to avoid memory leak.
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Analysis
by VulDB Data Team • 12/31/2024
The vulnerability identified as CVE-2023-52841 resides within the Linux kernel's media subsystem, specifically in the vidtv (video television) component responsible for video multiplexing operations. This flaw represents a classic null pointer dereference issue that could potentially lead to system instability or denial of service conditions when processing video data streams. The vulnerability affects systems utilizing the Linux kernel's video capture and processing capabilities, particularly those implementing the vidtv framework for handling television-related multimedia content.
The technical root cause of this vulnerability stems from inadequate error handling within the vidtv multiplexing code path. When the kernel attempts to duplicate strings using the kstrdup() function, which allocates memory and copies string data, the return value is not properly validated before subsequent operations. The kstrdup() function may fail during memory allocation, returning a NULL pointer, but the existing code does not check for this condition. This oversight creates a dangerous scenario where the system continues execution with a NULL pointer reference, leading to kernel panics or system crashes when the code attempts to dereference the invalid pointer.
The operational impact of CVE-2023-52841 extends beyond simple system crashes to include potential memory management issues that could be exploited by malicious actors. When kstrdup() fails, the system should properly handle the error condition and clean up any allocated resources. However, the original implementation failed to incorporate proper error handling that would call kfree() on previously allocated memory, resulting in memory leaks that could accumulate over time and degrade system performance. This dual nature of the vulnerability combines both immediate crash potential and long-term resource consumption issues that make it particularly concerning for production systems.
This vulnerability aligns with CWE-476, which specifically addresses NULL pointer dereference conditions in software implementations. The flaw demonstrates poor defensive programming practices where error conditions are not properly validated, creating opportunities for system instability. From an attack surface perspective, this vulnerability could be leveraged as part of a broader exploitation strategy, particularly in environments where video processing is heavily utilized or where denial of service attacks are a concern. The ATT&CK framework categorizes this type of vulnerability under T1499.004, which covers network denial of service attacks, as the vulnerability could be exploited to cause system unresponsiveness through kernel-level memory corruption.
The fix implemented for CVE-2023-52841 addresses both the immediate null pointer dereference issue and the associated memory leak problem. By adding proper validation of kstrdup() return values and implementing appropriate error handling with kfree() calls, the kernel's vidtv subsystem now correctly manages memory allocation failures. This solution follows established kernel development practices for robust error handling and resource management, ensuring that when memory allocation fails, the system properly cleans up resources and propagates errors rather than continuing execution with invalid pointers. The mitigation strategy effectively prevents both the immediate system crash conditions and the long-term memory consumption issues that could otherwise degrade system performance over time.