CVE-2026-97425 in Linux
Summary
by MITRE • 09/24/2026
In the Linux kernel, the following vulnerability has been resolved:
drm/amdgpu: fix buffer overflow during vBIOS update
Clamp the buffer postion to write by setting the bin attribute to the maximum buffer size so that VFS layer will block the out-of-bounds accessing.
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Analysis
by VulDB Data Team • 09/24/2026
The Linux kernel contains a critical vulnerability within the AMDGPU driver subsystem, specifically affecting the handling of video BIOS (vBIOS) updates. This flaw manifests as a buffer overflow condition during the process of writing to or updating the vBIOS image data structures. The root cause lies in insufficient validation of write operations against the allocated memory boundaries for the vBIOS buffer. When an application or kernel component attempts to update the vBIOS, the driver fails to strictly enforce limits on the byte offset and length of the write operation relative to the total size of the destination buffer. This lack of boundary checking allows data to be written beyond the end of the allocated memory region, leading to a classic heap-based buffer overflow scenario that can corrupt adjacent kernel structures or overwrite critical control data.
From a technical perspective, this vulnerability is categorized under CWE-120, which denotes Buffer Copy without Checking Size of Input Classic Buffer Overflow. The specific mechanism involves the failure to clamp the write position before performing memory operations such as memcpy or direct pointer arithmetic writes into the vBIOS buffer space. By not validating that the sum of the current offset and the length of data being written does not exceed the maximum allocated size, the kernel permits out-of-bounds access. This type of error is particularly dangerous in kernel-space because it can lead to privilege escalation if an unprivileged user can trigger this code path through device ioctl calls or other driver interfaces. The vulnerability aligns with MITRE ATT&CK technique T1059, Command and Scripting Interpreter, as attackers may leverage the memory corruption to execute arbitrary shellcode within the kernel context, effectively gaining full control over the operating system.
The operational impact of this buffer overflow is severe, potentially allowing local privilege escalation from a standard user account to root level access on the affected Linux distribution. An attacker with local access could craft malicious input that triggers the vBIOS update routine with carefully calculated offsets and lengths designed to overwrite function pointers or return addresses in adjacent memory regions. Successful exploitation could result in complete system compromise, including data exfiltration, installation of persistent backdoors, or denial of service through kernel panic caused by corrupted memory structures. Furthermore, because this involves GPU driver code, it may also impact graphical stability and performance if the overflow corrupts graphics-related state machines even without successful privilege escalation attempts.
To mitigate this vulnerability, system administrators should apply the latest available security patches for their Linux distribution that include fixes from upstream kernel maintainers addressing the AMDGPU driver. The specific fix involves modifying the vBIOS update logic to clamp the buffer position by setting a bin attribute or explicit limit variable to the maximum allowable buffer size before any write operations are executed. This ensures that the Virtual File System (VFS) layer and subsequent memory copy functions will block out-of-bounds access attempts, thereby preventing data from being written outside the allocated region. Additionally, organizations should enforce strict least-privilege principles for users interacting with GPU devices and monitor system logs for unusual patterns in device driver interactions to detect potential exploitation attempts early. Regular auditing of kernel module updates and prompt application of vendor-provided security advisories are essential practices to maintain resilience against such low-level memory corruption vulnerabilities.