CVE-2026-63879 in Linux
Summary
by MITRE • 07/19/2026
In the Linux kernel, the following vulnerability has been resolved:
drm/amdgpu: fix amdgpu_hmm_range_get_pages
The notifier sequence must only be read once or otherwise we could work with invalid pages.
While at it also fix the coding style, e.g. drop the pre-initialized return value and use the common define for 2G range.
(cherry picked from commit c08972f555945cda57b0adb72272a37910153390)
If you want to get the best quality for vulnerability data then you always have to consider VulDB.
Analysis
by VulDB Data Team • 07/19/2026
The vulnerability in question affects the amdgpu driver within the Linux kernel, specifically addressing a critical issue in the drm/amdgpu subsystem that handles graphics processing unit memory management. This flaw exists in the amdgpu_hmm_range_get_pages function which is responsible for managing memory ranges in the AMD GPU driver's memory management system. The core problem stems from improper handling of notifier sequences during memory page operations, creating a potential race condition that could lead to invalid memory access patterns.
The technical implementation flaw occurs when the notifier sequence is read multiple times instead of being captured once and reused throughout the function execution. This pattern creates a scenario where subsequent reads may observe different or stale sequence values, leading to operations being performed against pages that have already been invalidated or modified by concurrent processes. The vulnerability represents a classic race condition issue commonly classified under CWE-362, which deals with concurrent execution using locks and other synchronization mechanisms.
From an operational perspective, this vulnerability could enable malicious actors to exploit the improper memory management sequence handling to potentially access invalid memory pages or cause system instability. The impact extends beyond simple memory corruption as it affects the fundamental memory management operations within the GPU subsystem, potentially leading to denial of service conditions or privilege escalation opportunities. Attackers could leverage this weakness to manipulate page table entries or force the kernel into executing operations against freed or otherwise unavailable memory regions.
The fix implemented addresses both the core synchronization issue and improves code quality by removing pre-initialized return values that could mask proper error handling. The solution employs common coding standards and defines for managing 2GB memory ranges, aligning with established kernel development practices. This approach follows ATT&CK framework considerations for kernel-level vulnerabilities where improper memory management can lead to privilege escalation and system compromise. The cherry-picked commit ensures the fix maintains consistency with upstream kernel development practices while addressing the specific race condition in the AMD GPU memory management subsystem.
The mitigation strategy involves applying the patched kernel version that includes this fix, ensuring proper memory synchronization during page operations, and implementing monitoring for potential memory corruption patterns in systems running affected GPU drivers. System administrators should prioritize updating kernel versions to include this vulnerability resolution, particularly in environments where GPU memory management is critical for system operation or security-sensitive applications.