CVE-2023-52529

What it actually does

Failure to call usb_free_urb() after usb_alloc_urb() succeeds in sony_probe() leaves an allocated URB object unreleased on subsequent error paths, causing a kernel memory leak.

Why it matters to the business

Systems running affected kernels with Sony HID hardware may gradually exhaust kernel memory, leading to degraded performance or instability during prolonged operation or repeated device attach/detach cycles.

How an attack unfolds

An attacker with local access triggers the error path in sony_probe() by presenting a malformed or incompatible Sony device, causing the kernel to allocate but not free the URB and slowly deplete memory resources.

How to fix it

Apply the upstream fix in commit bb0707fde7492121917fd9ddb43829e96ec0bb9e or upgrade to a kernel containing this patch; rebuild and deploy the updated kernel image across affected systems.

How to confirm the fix worked

Confirm the presence of bb0707fde7492121917fd9ddb43829e96ec0bb9e in the kernel source tree or verify the running kernel version includes the HID sony memory-leak fix via kernel changelog inspection.

Typical attack path

1. Obtain local access or physical proximity to insert a Sony HID device
2. Trigger sony_probe() via device enumeration
3. Force an error after successful usb_alloc_urb()
4. Repeat attachment to accumulate leaked memory

How to detect it

Review kernel logs for repeated sony_probe failures accompanied by increasing slab or kmalloc memory usage; correlate with dmesg entries showing USB device attach events for Sony hardware.

What your security team should do

• Prioritize kernel upgrade on systems exposing Sony HID devices
• Audit custom kernel builds for the missing usb_free_urb() call
• Monitor memory usage trends on affected endpoints until patched