CVE-2010-5321

What it actually does

Memory leak in videobuf-core.c allows repeated mmap allocations on /dev/video to exhaust kernel memory without release, limited to 11 legacy drivers still using videobuf instead of videobuf2.

Why it matters to the business

Local users on older Linux kernels can trigger memory exhaustion leading to system slowdowns or crashes on affected video hardware, with limited real-world exposure given the age and narrow driver scope.

How an attack unfolds

A local attacker opens a legacy /dev/video device backed by an unported videobuf driver and issues a sequence of mmap calls that each allocate new kernel buffers; the buffers are never freed, steadily consuming memory until the system becomes unresponsive.

How to fix it

Migrate the remaining 11 drivers to videobuf2, upgrade to a modern kernel where videobuf has been removed, or restrict unprivileged access to video devices on legacy systems.

How to confirm the fix worked

Confirm that affected drivers have been converted to videobuf2 or removed; monitor kernel memory usage under sustained mmap workloads on video nodes; verify absence of the vulnerable videobuf-core.c allocation path in running kernels.

Typical attack path

1. Obtain local shell or process execution on the target Linux system
2. Open a /dev/video node belonging to one of the 11 unported drivers
3. Issue repeated mmap system calls that force new videobuf allocations
4. Continue until kernel memory is exhausted and the system degrades or panics

How to detect it

Review kernel logs and process accounting for repeated mmap activity on video character devices; correlate with unexplained kernel memory growth on systems that still load videobuf-based drivers.

What your security team should do

• Identify systems still running Linux 2.6–4.x with legacy videobuf drivers
• Apply kernel upgrades or driver patches that eliminate videobuf usage
• Restrict /dev/video access via device ACLs or udev rules for non-privileged users
• Monitor memory consumption on systems exposing video devices