CVE-2011-1016 in Linux
Summary
by MITRE
The Radeon GPU drivers in the Linux kernel before 2.6.38-rc5 do not properly validate data related to the AA resolve registers, which allows local users to write to arbitrary memory locations associated with (1) Video RAM (aka VRAM) or (2) the Graphics Translation Table (GTT) via crafted values.
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Analysis
by VulDB Data Team • 10/18/2021
The vulnerability identified as CVE-2011-1016 represents a critical memory corruption flaw within the Radeon GPU driver implementation in the Linux kernel ecosystem. This weakness exists in kernel versions prior to 2.6.38-rc5 and stems from inadequate validation mechanisms for data processing related to anti-aliasing resolve registers. The flaw specifically affects the graphics subsystem's handling of GPU memory operations, creating potential pathways for privilege escalation and system compromise. The vulnerability's impact extends beyond simple memory corruption as it enables attackers to manipulate critical graphics memory regions through carefully crafted input values.
The technical exploitation of this vulnerability occurs through improper validation of graphics register data during anti-aliasing operations. When the Radeon driver processes AA resolve register values, it fails to adequately verify the legitimacy of these parameters before writing to memory locations. This validation failure allows local attackers to craft malicious register values that direct the driver to write data to arbitrary memory addresses within either Video RAM or Graphics Translation Table regions. The lack of proper bounds checking and input sanitization creates a direct path for memory corruption that can be leveraged for privilege escalation or system instability.
From an operational perspective, this vulnerability presents significant risks to Linux systems utilizing Radeon graphics hardware. Local attackers with minimal privileges can exploit this flaw to gain write access to critical graphics memory spaces, potentially leading to privilege escalation to kernel-level access. The vulnerability affects systems running kernel versions up to and including 2.6.37, making it particularly concerning for enterprise environments where kernel updates may be delayed or restricted. The impact extends to both VRAM and GTT memory regions, which are fundamental components of GPU memory management and graphics processing operations.
The vulnerability aligns with CWE-125, which describes "Out-of-bounds Read" conditions that can lead to memory corruption, and also relates to CWE-787, "Out-of-bounds Write" representing the direct memory corruption aspect of this flaw. From an attack framework perspective, this vulnerability maps to ATT&CK technique T1068, "Exploitation for Privilege Escalation," and T1547.001, "Registry Run Keys / Startup Folder," as local privilege escalation can lead to persistent access. The exploitability of this vulnerability is enhanced by the fact that it requires no special privileges beyond local user access, making it particularly dangerous in multi-user environments where users may have legitimate access to graphics processing functions.
Mitigation strategies for CVE-2011-1016 primarily involve kernel version updates to 2.6.38-rc5 or later, where the validation mechanisms for AA resolve registers have been properly implemented. System administrators should prioritize kernel updates across all affected systems, particularly those running older kernel versions. Additionally, implementing proper access controls and monitoring for unusual graphics memory operations can help detect potential exploitation attempts. The vulnerability demonstrates the importance of proper input validation in kernel drivers and highlights the need for comprehensive security testing of graphics subsystem components. Organizations should also consider implementing runtime protections such as kernel address space layout randomization and stack canaries to further reduce the exploitability of similar vulnerabilities in the graphics subsystem.