CVE-2022-49240: 
Linux Debian vulnerability analysis and mitigation

CVE-2022-49240 is a vulnerability in the Linux kernel affecting the ASoC (ALSA System on Chip) MediaTek MT8195 sound driver. The vulnerability was discovered in the mt8195mt6359rt1019rt5682devprobe function, where a reference count leak occurs due to improper error handling of device node pointers returned by ofparse_phandle(). The issue was publicly disclosed and documented on February 26, 2025 (NVD).

The vulnerability stems from improper reference counting in the Linux kernel's sound driver for MediaTek MT8195. Specifically, when the ofparsephandle() function returns a devicenode pointer, it increments the reference count. The original code only called ofnode_put() in the regular execution path but failed to properly handle the reference count in error paths, leading to a potential reference count leak (Kernel Commit).

The reference count leak in the kernel's sound driver could potentially lead to memory resource exhaustion over time, though the practical impact is limited due to the nature of the vulnerability being in a specific hardware driver's error path.

The vulnerability has been patched in the Linux kernel through a fix that properly handles the device node reference counting in both regular and error paths. The fix involves adding appropriate ofnodeput() calls in the error handling path of the mt8195mt6359rt1019rt5682dev_probe function (Kernel Fix).