CVE-2024-26911

What it actually does

alloc_range() in the Linux kernel DRM buddy allocator incorrectly returns success instead of -ENOSPC when total allocated size is less than required in corner cases, resulting in invalid memory block handling.

Why it matters to the business

Systems may experience intermittent display corruption during boot into desktop environments or while running graphics-intensive applications, leading to degraded user experience and potential need for restarts or workarounds on affected Linux kernels.

How an attack unfolds

A local user triggers memory allocation patterns in the DRM subsystem (such as during KDE Plasma startup or game execution) that hit the corner case, causing the function to report success despite insufficient blocks and subsequent display corruption.

How to fix it

Update the Linux kernel to a version containing commit 4b59c3fada06e5e8010ef7700689c71986e667a2 or later stable releases that include the fix for alloc_range() error handling.

How to confirm the fix worked

Verify kernel source or package version includes the referenced commit; test graphics workloads that previously triggered corruption to confirm absence of symptoms; review dmesg or journal logs for related allocation errors post-update.

Typical attack path

1. Obtain local user access on a Linux system running an affected kernel
2. Trigger graphics operations that invoke alloc_range() with sizes exposing the corner case
3. Observe or induce display corruption due to incorrect success return

How to detect it

Review system logs for display or graphics corruption events around boot or application launch; correlate with kernel version checks to identify unpatched systems; no specific post-exploitation artifacts beyond observed visual artifacts.

What your security team should do

• Prioritize kernel upgrades on systems with affected DRM graphics drivers
• Monitor for display corruption reports as indicators of exposure until patched
• Apply updates within standard patch cycles given low exploitability