CVE-2021-47030 in Linux
Summary
by MITRE • 02/28/2024
In the Linux kernel, the following vulnerability has been resolved:
mt76: mt7615: fix memory leak in mt7615_coredump_work
Similar to the issue fixed in mt7921_coredump_work, fix a possible memory leak in mt7615_coredump_work routine.
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Analysis
by VulDB Data Team • 12/06/2024
The vulnerability identified as CVE-2021-47030 represents a memory leak condition within the Linux kernel's wireless networking subsystem, specifically affecting the mt76 driver family. This issue resides in the mt7615_coredump_work routine which handles crash dump processing for MediaTek MT7615 wireless network adapters. The flaw manifests as an improper memory management procedure where allocated memory resources are not correctly released during the core dump processing workflow, leading to gradual memory consumption that can eventually impact system stability and performance.
This memory leak vulnerability stems from inadequate resource cleanup within the driver's error handling and crash reporting mechanisms. The mt7615_coredump_work function is responsible for collecting and processing core dump information when the wireless adapter encounters critical errors or crashes. The flaw occurs when the routine fails to properly deallocate memory buffers that were allocated during the core dump collection process, creating a persistent memory leak that accumulates over time with repeated error conditions or system restarts. This type of vulnerability directly relates to CWE-401, which describes improper resource management leading to memory leaks in software systems.
The operational impact of this vulnerability extends beyond simple memory consumption, potentially affecting system reliability and network performance. When the memory leak accumulates over time, it can contribute to system slowdowns, reduced available memory for other processes, and in severe cases may lead to system instability or crashes. The issue is particularly concerning in embedded systems or devices running continuous network operations where the memory leak could compound over extended periods, ultimately degrading system performance or causing unexpected shutdowns. Network administrators and system operators may observe gradual performance degradation or memory exhaustion issues that could be attributed to this driver-level memory management flaw.
The vulnerability was addressed by implementing proper memory cleanup procedures similar to those already applied to the mt7921_coredump_work routine, demonstrating a pattern of remediation for similar issues within the same driver family. This fix ensures that all allocated memory buffers are properly freed during the core dump processing workflow, preventing the accumulation of leaked memory resources. The resolution follows established security practices for kernel-level memory management and aligns with best practices for preventing resource exhaustion attacks. Security teams should prioritize this patch deployment across systems utilizing MediaTek MT7615 wireless adapters, particularly in environments where continuous network operations and memory efficiency are critical. The fix also reinforces the importance of comprehensive memory management practices in kernel drivers, as highlighted in various ATT&CK framework techniques related to system resource exhaustion and denial of service conditions.