CVE-2024-40932

What it actually does

Memory leak in drm/exynos/vidi .get_modes() where a duplicated EDID buffer is allocated but never freed, leading to gradual kernel memory exhaustion on affected Exynos video drivers.

Why it matters to the business

Long-running Linux systems using the vidi driver may experience increasing memory pressure, potential out-of-memory kills, or degraded performance; the issue affects many kernel versions but carries low exploitation probability.

How an attack unfolds

An attacker with local access or the ability to trigger EDID mode queries (via display hotplug or graphics API calls) repeatedly invokes the get_modes path, causing the kernel to allocate and leak EDID structures without freeing them until the system is rebooted or the driver is reloaded.

How to fix it

Upgrade the Linux kernel to a version containing commit 540ca99729e28dbe902b01039a3b4bd74520a819 or later; rebuild and reboot with the patched kernel. No configuration workaround exists.

How to confirm the fix worked

Confirm the running kernel Git commit or version includes 540ca99729e28dbe902b01039a3b4bd74520a819; inspect source for the free() call after the duplicated EDID allocation in vidi_get_modes(); monitor kernel memory statistics for the vidi driver over extended runtime.

Typical attack path

1. Obtain local access or control a process that can interact with the DRM subsystem
2. Trigger repeated calls to vidi .get_modes() through display configuration changes or graphics APIs
3. Observe gradual increase in kernel memory usage attributable to the vidi driver
4. Continue until memory pressure leads to system instability or denial of service

How to detect it

Review kernel logs and memory accounting for sustained allocations from the vidi driver without corresponding frees; look for repeated DRM mode-setting events coinciding with rising slab or kmalloc usage in the exynos subsystem.

What your security team should do

• Prioritize kernel updates on systems exposing the Exynos vidi driver within the next maintenance window
• Monitor memory usage trends on affected hosts using standard kernel accounting tools
• Review downstream distribution packages for backported fixes once available