CVE-2024-49896 in Linux
Summary
by MITRE • 10/21/2024
In the Linux kernel, the following vulnerability has been resolved:
drm/amd/display: Check stream before comparing them
[WHAT & HOW]
amdgpu_dm can pass a null stream to dc_is_stream_unchanged. It is necessary to check for null before dereferencing them.
This fixes 1 FORWARD_NULL issue reported by Coverity.
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Analysis
by VulDB Data Team • 01/19/2026
The vulnerability CVE-2024-49896 represents a critical null pointer dereference flaw within the AMD GPU display driver component of the Linux kernel. This issue specifically affects the drm/amd/display subsystem where the amdgpu_dm driver implementation fails to properly validate stream parameters before attempting to access them. The flaw occurs during the dc_is_stream_unchanged function call where a null stream pointer can be passed without proper validation, leading to potential system crashes or unauthorized access conditions. This vulnerability directly impacts systems utilizing AMD graphics hardware through the amdgpu driver stack and represents a fundamental failure in input validation practices.
The technical root cause of this vulnerability stems from inadequate null pointer checking within the display management code path. When the amdgpu_dm driver processes display stream changes, it invokes the dc_is_stream_unchanged function without first verifying that the stream parameter is not null. This forward null dereference condition creates an opportunity for attackers to trigger kernel crashes or potentially escalate privileges through controlled input manipulation. The vulnerability has been categorized under CWE-476 as a null pointer dereference, which is a well-known class of software defects that can lead to system instability and security implications.
From an operational perspective, this vulnerability poses significant risks to Linux systems running AMD graphics hardware, particularly in enterprise environments where system stability is paramount. The flaw can result in unexpected system crashes, display corruption, or complete system hang conditions that affect user productivity and system availability. Attackers could potentially exploit this vulnerability to cause denial of service conditions or, in more sophisticated scenarios, leverage the kernel memory corruption to gain unauthorized access to system resources. The impact is particularly concerning for servers and embedded systems where continuous operation is required and any system crash could have cascading effects on network infrastructure.
Security mitigation strategies for this vulnerability should focus on immediate patch deployment through standard kernel update procedures. System administrators should prioritize applying the latest kernel updates that include the fix for this null pointer dereference issue. Additionally, monitoring systems should be configured to detect unusual crash patterns or display-related anomalies that might indicate exploitation attempts. The fix implemented addresses the specific forward null condition by adding proper null stream validation before function invocation, aligning with ATT&CK technique T1068 which covers local privilege escalation through kernel vulnerabilities. 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 display subsystem.