CVE-2026-64215 in Linux
Summary
by MITRE • 07/24/2026
In the Linux kernel, the following vulnerability has been resolved:
drm/msm/a6xx: Check kzalloc return in a8xx_hfi_send_perf_table
Check the return value of kzalloc() to prevent a NULL pointer dereference on allocation failure.
Patchwork: https://patchwork.freedesktop.org/patch/721342/
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Analysis
by VulDB Data Team • 07/24/2026
This vulnerability resides within the drm/msm/a6xx subsystem of the Linux kernel, specifically affecting the a8xx_hfi_send_perf_table function. The issue represents a classic null pointer dereference flaw that occurs when memory allocation fails during kernel operation. The vulnerability manifests when kzalloc() returns NULL upon allocation failure, but the calling code fails to check this return value before proceeding with operations that assume successful memory allocation. This particular flaw affects Qualcomm Snapdragon 8xx series GPU drivers and their associated HFI (Hardware Interface) communication mechanisms used for performance table management.
The technical implementation of this vulnerability stems from inadequate error handling in kernel memory allocation paths. When kzalloc() fails to allocate the requested memory block, it returns a NULL pointer instead of a valid memory address. The function a8xx_hfi_send_perf_table does not validate this return value, subsequently passing the NULL pointer to downstream operations that expect valid memory references. This pattern violates fundamental kernel safety principles and creates an exploitable condition where malicious input or resource exhaustion could trigger the null pointer dereference during normal operation.
The operational impact of this vulnerability extends beyond simple system crashes to potentially enable privilege escalation or denial of service attacks within the graphics subsystem. Attackers could exploit this weakness by triggering conditions that cause memory allocation failures, thereby forcing the kernel to attempt operations on NULL pointers. Such exploitation could result in complete system instability or provide attackers with opportunities to gain elevated privileges through controlled memory corruption. The vulnerability affects systems running affected Linux kernel versions with Qualcomm Snapdragon 8xx GPU support, particularly those utilizing the msm graphics driver framework.
Mitigation strategies for this vulnerability involve implementing proper error checking mechanisms in the affected kernel code paths. The recommended approach requires adding explicit return value validation after each kzalloc() call to ensure memory allocation success before proceeding with subsequent operations. This follows established security practices and aligns with CWE-476 which specifically addresses null pointer dereference conditions. Additionally, system administrators should apply the upstream patch available through the freedesktop.org patchwork link provided, which implements the necessary return value checks. The fix demonstrates adherence to ATT&CK technique T1068 by preventing unauthorized privilege escalation through kernel memory management flaws and follows secure coding practices for kernel development as outlined in the Linux kernel security documentation.
The vulnerability represents a fundamental flaw in defensive programming practices within kernel space code, where proper error handling and resource validation are essential. This type of issue highlights the critical importance of memory allocation validation in operating system kernels, where even minor oversight in error checking can result in severe security implications. The fix serves as a reminder of the necessity for comprehensive testing and validation procedures in kernel development environments, particularly when dealing with memory management subsystems that handle critical hardware interfaces such as GPU communication channels.