CVE-2022-3078 in Linux
Summary
by MITRE • 09/02/2022
An issue was discovered in the Linux kernel through 5.16-rc6. There is a lack of check after calling vzalloc() and lack of free after allocation in drivers/media/test-drivers/vidtv/vidtv_s302m.c.
Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.
Analysis
by VulDB Data Team • 10/11/2022
The vulnerability identified as CVE-2022-3078 resides within the Linux kernel version 5.16-rc6 and earlier, specifically within the video test driver component located at drivers/media/test-drivers/vidtv/vidtv_s302m.c. This issue represents a classic memory management flaw that arises from improper handling of dynamic memory allocation operations within kernel space. The root cause stems from the absence of proper validation following memory allocation calls and insufficient cleanup procedures after resource allocation, creating potential pathways for system instability and security exploitation.
The technical flaw manifests through inadequate error checking after invoking the vzalloc() function, which is a kernel memory allocation routine designed to allocate virtually contiguous memory blocks. When vzalloc() fails to allocate the requested memory, it returns a null pointer, but the code fails to verify this condition before proceeding with subsequent operations. Additionally, the code lacks proper deallocation mechanisms following successful allocations, leading to potential memory leaks that could accumulate over time and eventually impact system performance or availability. This pattern of memory management deficiency aligns with CWE-401, which specifically addresses improper handling of memory allocation failures and resource leaks in software systems.
The operational impact of this vulnerability extends beyond simple memory consumption issues, as improper memory handling in kernel space can lead to system crashes, denial of service conditions, or potentially exploitable states that might allow privilege escalation. When the kernel fails to properly validate allocation results or clean up resources, it creates an environment where subsequent operations might encounter unexpected memory states or corrupted data structures. This vulnerability particularly affects systems utilizing the video test driver functionality, where the vidtv_s302m.c component handles S302M audio data transmission protocols. The potential for exploitation increases when the system experiences memory pressure or when the driver is repeatedly invoked, as the accumulation of leaked memory could eventually cause system instability or complete system failure.
Mitigation strategies for CVE-2022-3078 should focus on implementing proper error checking mechanisms following all memory allocation calls, particularly those involving vzalloc() and similar kernel memory allocation functions. System administrators should ensure that the kernel is updated to versions that contain the appropriate patches addressing this memory management issue. The fix typically involves adding explicit null pointer checks after vzalloc() calls and implementing proper cleanup routines using functions such as vfree() to release allocated memory. Organizations should also consider implementing monitoring systems to detect memory leaks or unusual memory consumption patterns that might indicate this vulnerability's exploitation. From an ATT&CK framework perspective, this vulnerability could be categorized under T1068 for privilege escalation or T1499 for resource hijacking, depending on how it is leveraged by adversaries. The vulnerability demonstrates the critical importance of proper memory management practices in kernel development, as highlighted by the principle that all memory allocation functions should be validated for success before use and that all allocated resources should be properly freed upon completion of their use.