CVE-2024-50175

/// Technical description

In the Linux kernel, the following vulnerability has been resolved:

media: qcom: camss: Remove use_count guard in stop_streaming

The use_count check was introduced so that multiple concurrent Raw Data

Interfaces RDIs could be driven by different virtual channels VCs on the

CSIPHY input driving the video pipeline.

This is an invalid use of use_count though as use_count pertains to the

number of times a video entity has been opened by user-space not the number

of active streams.

If use_count and stream-on count don't agree then stop_streaming() will

break as is currently the case and has become apparent when using CAMSS

with libcamera's released softisp 0.3.

The use of use_count like this is a bit hacky and right now breaks regular

usage of CAMSS for a single stream case. Stopping qcam results in the splat

below, and then it cannot be started again and any attempts to do so fails

with -EBUSY.

[ 1265.509831] WARNING: CPU: 5 PID: 919 at drivers/media/common/videobuf2/videobuf2-core.c

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References