CVE-2022-50566

In the Linux kernel, the add_mtd_device() function in the MTD subsystem allocates a device name dynamically. However, if register_device() fails, the allocated name is leaked because the function does not call put_device() to release the reference. This memory leak is observable via kmemleak, as shown in the CVE description [1].

The vulnerability is triggered when an MTD device registration fails, which can occur under error conditions such as invalid device parameters or driver issues. An attacker with the ability to load a faulty MTD module or cause registration failures could repeatedly trigger the leak, leading to memory exhaustion over time. No special privileges are required beyond module loading capability.

The impact is a memory leak that, if exploited repeatedly, could result in denial of service by exhausting system memory. The leak is limited to the device name string (typically small) but can accumulate.

The fix was applied in multiple Linux kernel stable branches. The resolved commits ensure that put_device() is called on the device when registration fails, properly releasing the allocated name. References [1], [2], and [3] point to the specific fix commits in the stable kernels.