CVE-2023-54183

What it actually does

Incorrect error handling in v4l2_fwnode_parse_link() causes fwnode reference counts to be leaked when fwnode_graph_get_remote_endpoint() or fwnode_graph_get_port_parent() fails, because the wrong handle is passed to fwnode_handle_put().

Why it matters to the business

Long-running systems using V4L2 media drivers may experience gradual kernel memory exhaustion, leading to degraded video capture or device-tree parsing functionality and eventual stability issues on affected Linux kernels.

How an attack unfolds

An attacker supplies a malformed device-tree or ACPI graph that forces the error paths in v4l2_fwnode_parse_link(); repeated triggering of the function without the corrected reference-release logic slowly depletes kernel memory until the system becomes unresponsive.

How to fix it

Upgrade the Linux kernel to a version containing commit 2342942331e1f034ff58f293e10d0d9b7581601f (or later stable backports) that adds proper error handling and the correct fwnode_handle_put() calls.

How to confirm the fix worked

Confirm the running kernel contains the referenced commit or is newer than the fixed release; alternatively, inspect the source of v4l2_fwnode_parse_link() for the added goto error path and balanced reference release.

Typical attack path

1. Identify a system exposing V4L2 media device registration via device tree or ACPI
2. Craft input that triggers fwnode_graph_get_remote_endpoint() or fwnode_graph_get_port_parent() failure
3. Repeatedly exercise the parsing path to accumulate unreleased fwnode references
4. Monitor for kernel memory pressure or OOM conditions in the media subsystem

How to detect it

Review kernel logs for repeated v4l2_fwnode_parse_link errors combined with rising slab or kmemleak reports; correlate with device-tree parsing events on systems that load media drivers.

What your security team should do

• Apply the kernel update containing commit 2342942331e1f034ff58f293e10d0d9b7581601f as soon as vendor packages are available
• Prioritize systems that register V4L2 devices through device tree or ACPI graphs
• Monitor kernel memory usage on media-enabled hosts until patches are deployed