CVE-2021-47030: 
Linux Kernel vulnerability analysis and mitigation

CVE-2021-47030 is a memory leak vulnerability discovered in the Linux kernel affecting the mt7615_coredump_work routine in the mt76 wireless driver. The vulnerability was identified in Linux kernel versions from 5.12 up to (excluding) 5.12.4. Similar to an issue previously fixed in mt7921_coredump_work, this vulnerability could result in memory not being properly freed under certain conditions (NVD, Kernel Patch).

The vulnerability is classified as CWE-401 (Missing Release of Memory after Effective Lifetime) with a CVSS v3.1 base score of 5.5 (Medium). The issue occurs in the mt7615_coredump_work function where memory allocated for SKB (Socket Buffer) is not properly freed when the coredump size exceeds MT76_CONNAC_COREDUMP_SZ, leading to a memory leak. The vulnerability requires local access and low attack complexity to exploit (NVD).

The vulnerability can lead to memory leaks in the Linux kernel, potentially causing system resource exhaustion over time. While the impact is limited to availability (no confidentiality or integrity impacts), it could affect system stability and performance if exploited continuously (Red Hat).

The vulnerability requires local access with low attack complexity to exploit. An attacker would need local user privileges to trigger the memory leak condition in the mt7615_coredump_work routine (NVD).

The vulnerability has been fixed in the Linux kernel through patches that properly free the SKB memory when the coredump size exceeds the maximum limit. The fix involves adding a dev_kfree_skb(skb) call before continuing the loop when the size check fails. Users should upgrade to Linux kernel version 5.12.4 or later to address this vulnerability (Kernel Patch).