CVE-2022-50757

Vulnerability

In the Linux kernel's camss (Camera Subsystem) driver, when starting video streaming fails (e.g., due to media pipeline validation failure returning EPIPE), the driver fails to return the received buffers to the videobuf2 framework. This triggers a kernel warning from vb2_start_streaming() because it expects all buffers to be returned after a failed start [1][2].

Exploitation

The vulnerability is triggered by attempting to start a video stream when the media pipeline link validation fails. This can be caused by a user-space application initiating streaming with an invalid configuration. No special privileges beyond access to the camera device are required; however, the attacker must be able to interact with the V4L2 interface.

Impact

The bug results in a kernel stack trace and warning message being logged, which can fill system logs and cause a denial of service if repeated. While the warning itself is not exploitable for privilege escalation, it indicates a broken error handling path that could be leveraged in conjunction with other vulnerabilities [3].

Mitigation

The fix is included in Linux kernel stable updates: commits c8f3582345e6, d1c44928bb3c, 24df4fa3e795, and 75954cde8a5c. Affected systems should apply the latest kernel updates to prevent this warning [4].