Low [CVE-2026-68216] Linux kernel: `pwc` media driver resource leak via `start_streaming ` failure

In the Linux kernel, the following vulnerability has been resolved: media: pwc: Return queued buffers on start_streaming() failure The vb2 framework hands buffers to the driver via buf_queue() before calling start_streaming().

If start_streaming() returns an error without first returning those buffers via vb2_buffer_done(), vb2_start_streaming() fires WARN_ON(owned_by_drv_count) and the queued buffers leak. pwc's start_streaming() had two early returns that hit this trap: -ENODEV when the USB device was already disconnected, and -ERESTARTSYS when mutex_lock_interruptible() was interrupted by a signal.

Call the existing pwc_cleanup_queued_bufs() helper with VB2_BUF_STATE_QUEUED before returning (matching the state already used by the pwc_isoc_init() error path in the same function). When the `start_streaming()` function fails, it does not properly return queued buffers, leading to a resource leak.

This can occur if the USB device is disconnected or if a mutex lock is interrupted. A local attacker could potentially exploit this to cause a Denial of Service (DoS) due to resource exhaustion.

Red Hat severity: Low — CVSS 3.3 (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L). Weakness: CWE-772.

Affected Red Hat products: Red Hat Enterprise Linux 7; Red Hat Enterprise Linux 8; Red Hat Enterprise Linux 9; Red Hat OpenShift Container Platform 4.