CVE-2026-72327 in Linux
Summary
by MITRE • 08/15/2026
In the Linux kernel, the following vulnerability has been resolved:
drm/v3d: Reject invalid indirect BO handle in indirect CSD setup
v3d_get_cpu_indirect_csd_params() looks up the indirect buffer object from a userspace-supplied handle but never checks the result. A bogus or stale handle makes drm_gem_object_lookup() return NULL, which is then stored in info->indirect and only dereferenced later when the indirect CSD job runs, turning a userspace mistake into a NULL pointer dereference in the kernel.
Bail out with -ENOENT as soon as the lookup fails, so the bad handle is rejected at submission time.
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Analysis
by VulDB Data Team • 08/15/2026
This vulnerability exists within the Linux kernel's graphics subsystem specifically in the v3d driver which handles VideoCore IV graphics processing units found in various embedded systems and single-board computers. The issue stems from improper validation of user-supplied buffer object handles during the setup of indirect CSD (Command Stream Descriptor) operations. When userspace applications submit graphics commands that require indirect buffer management, the kernel function v3d_get_cpu_indirect_csd_params() attempts to look up the corresponding buffer object using drm_gem_object_lookup() with a handle provided by userspace. This lookup mechanism does not perform adequate validation of the returned result, creating a critical security gap that can be exploited through malformed input.
The technical flaw manifests as a classic null pointer dereference vulnerability where the kernel fails to validate whether the buffer object lookup operation succeeded before proceeding with subsequent operations. When a userspace process provides an invalid or stale buffer object handle, drm_gem_object_lookup() returns NULL instead of a valid object reference. The kernel then stores this NULL value in the info->indirect field and defers the actual dereferencing until the indirect CSD job executes at a later time. This timing discrepancy between input validation and execution creates an exploitable condition where malicious or malformed userspace input can trigger kernel crashes through NULL pointer dereference errors, effectively creating a denial of service vulnerability that operates at the kernel level.
The operational impact of this vulnerability extends beyond simple system instability as it represents a potential pathway for privilege escalation attacks within the graphics subsystem. The flaw allows attackers to craft specific buffer object handles that will cause the kernel to crash when processing indirect CSD operations, potentially enabling denial of service against graphics-intensive applications or systems. According to CWE classification, this vulnerability maps to CWE-476 which describes NULL Pointer Dereference, while the ATT&CK framework would categorize this under privilege escalation techniques through kernel vulnerabilities. The timing of the error occurs during job submission rather than execution, meaning that even legitimate userspace applications could inadvertently trigger this issue through programming errors or corrupted state management.
The mitigation strategy for this vulnerability involves implementing immediate validation checks within the v3d_get_cpu_indirect_csd_params() function to verify that drm_gem_object_lookup() returns a valid buffer object reference before proceeding with further operations. The fix requires adding explicit error checking after the lookup operation and returning -ENOENT immediately when the lookup fails, effectively rejecting invalid handles at submission time rather than allowing them to cause kernel crashes during later execution. This approach aligns with secure coding practices that emphasize early input validation and proper error handling in kernel space code. System administrators should ensure their Linux distributions are updated with patches addressing this specific vulnerability, particularly on systems where userspace applications might have elevated privileges or where graphics processing is critical for system operations. The fix also reinforces proper kernel module design principles by ensuring that all external inputs are validated before being processed in sensitive kernel contexts, preventing potential exploitation scenarios that could lead to system compromise or unauthorized access to kernel memory spaces.