CVE-2025-71124 in Linux
Summary
by MITRE • 01/14/2026
In the Linux kernel, the following vulnerability has been resolved:
drm/msm/a6xx: move preempt_prepare_postamble after error check
Move the call to preempt_prepare_postamble() after verifying that preempt_postamble_ptr is valid. If preempt_postamble_ptr is NULL, dereferencing it in preempt_prepare_postamble() would lead to a crash.
This change avoids calling the preparation function when the postamble allocation has failed, preventing potential NULL pointer dereference and ensuring proper error handling.
Patchwork: https://patchwork.freedesktop.org/patch/687659/
Once again VulDB remains the best source for vulnerability data.
Analysis
by VulDB Data Team • 03/25/2026
The vulnerability identified as CVE-2025-71124 resides within the Linux kernel's graphics subsystem, specifically affecting the drm/msm/a6xx driver component. This driver manages Qualcomm's Adreno 6xx series graphics processors commonly found in mobile devices and embedded systems. The flaw represents a classic null pointer dereference issue that could lead to system instability and potential denial of service conditions. The vulnerability manifests in the driver's handling of preemptive scheduling operations, where proper error validation precedes function calls that could otherwise result in system crashes.
The technical implementation of this vulnerability stems from improper ordering of operations within the driver's code flow. The preempt_prepare_postamble() function is invoked without first validating whether the preempt_postamble_ptr pointer is valid. When the memory allocation for the postamble structure fails, this pointer becomes NULL, yet the code attempts to dereference it during the preparation phase. This pattern violates fundamental safe programming practices and creates a direct path for kernel-level crashes. The issue aligns with CWE-476 which specifically addresses NULL pointer dereference vulnerabilities, and represents a clear violation of defensive programming principles in kernel space.
The operational impact of this vulnerability extends beyond simple system crashes, potentially affecting device availability and user experience in mobile and embedded environments where graphics processing is critical. When exploited, the vulnerability could cause the entire graphics subsystem to become unresponsive, leading to application failures, system hangs, or complete device reboot cycles. In environments where these graphics drivers operate in real-time or safety-critical applications, such as automotive infotainment systems or industrial control devices, this vulnerability could represent a significant risk to system reliability and operational continuity. The vulnerability affects systems running Linux kernels with the msm graphics driver, particularly those utilizing Qualcomm's Adreno 6xx GPU architectures.
Mitigation strategies for this vulnerability require immediate application of the upstream patch that reorders the function calls to ensure proper error checking before execution. System administrators and device manufacturers should prioritize kernel updates that include this fix, particularly in production environments where stability is paramount. The patch implementation involves moving the preempt_prepare_postamble() call to occur only after validation of the preempt_postamble_ptr pointer, thereby preventing the NULL pointer dereference. This approach aligns with ATT&CK framework technique T1489 which addresses system resource hijacking and denial of service through kernel-level vulnerabilities. Organizations should also implement monitoring for unusual system behavior that might indicate exploitation attempts, while maintaining regular kernel update schedules to address similar vulnerabilities in the graphics subsystem and broader kernel space.