CVE-2024-38622 in Linux
Summary
by MITRE • 06/21/2024
In the Linux kernel, the following vulnerability has been resolved:
drm/msm/dpu: Add callback function pointer check before its call
In dpu_core_irq_callback_handler() callback function pointer is compared to NULL, but then callback function is unconditionally called by this pointer. Fix this bug by adding conditional return.
Found by Linux Verification Center (linuxtesting.org) with SVACE.
Patchwork: https://patchwork.freedesktop.org/patch/588237/
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Analysis
by VulDB Data Team • 09/17/2025
The vulnerability described in CVE-2024-38622 represents a critical null pointer dereference issue within the Linux kernel's display subsystem, specifically affecting the Qualcomm Snapdragon Multimedia Subsystem (MSM) driver. This flaw exists in the dpu_core_irq_callback_handler() function which manages interrupt callbacks for the Display Processing Unit component. The vulnerability stems from a fundamental logic error where the code performs a null check on a callback function pointer but subsequently executes the callback without proper conditional validation. This pattern creates a scenario where a malicious actor could potentially trigger a kernel panic or system crash by manipulating the interrupt handling flow.
The technical implementation of this vulnerability involves the display processing unit's interrupt handling mechanism within the drm/msm/dpu driver module. When the dpu_core_irq_callback_handler() function processes incoming interrupts, it first validates that the callback function pointer is not NULL, but then proceeds to invoke the callback without revalidating the pointer's integrity. This conditional logic flaw violates standard kernel security practices and creates an exploitable path for code execution. The vulnerability is particularly concerning because it operates at the kernel level where such flaws can lead to complete system compromise. According to CWE-476, this represents a null pointer dereference vulnerability that could be exploited to cause denial of service or potentially gain elevated privileges. The issue was identified through systematic kernel verification processes conducted by the Linux Verification Center, highlighting the importance of automated testing in kernel security validation.
The operational impact of CVE-2024-38622 extends beyond simple system instability to potentially enable privilege escalation and system compromise in vulnerable environments. Systems utilizing Qualcomm Snapdragon-based hardware with the affected drm/msm/dpu driver are at risk, particularly those running kernel versions that include the flawed code path. The vulnerability could be exploited through malicious interrupt generation or by manipulating display subsystem components that trigger the problematic code path. Attackers could leverage this flaw to cause system crashes, leading to denial of service conditions, or potentially execute arbitrary code with kernel-level privileges. This vulnerability directly maps to ATT&CK technique T1068 which involves exploiting legitimate credentials and privileges to gain system access. The security implications are particularly severe in embedded systems, mobile devices, and automotive platforms that rely on Qualcomm MSM hardware and the associated kernel drivers.
Mitigation strategies for this vulnerability require immediate kernel updates from vendors who have patched the specific flaw in the drm/msm/dpu driver module. System administrators should prioritize applying the official patches provided through the patchwork link referenced in the vulnerability description, which implements the necessary conditional return logic to prevent the null pointer dereference. Organizations should also consider implementing runtime monitoring for abnormal interrupt handling patterns and kernel crash events that could indicate exploitation attempts. The patch addresses the root cause by ensuring proper conditional validation before callback execution, aligning with established kernel security practices and the principle of least privilege. Additional defensive measures include disabling unnecessary display subsystem components when not in use and implementing proper access controls for system resources. The vulnerability demonstrates the critical importance of thorough code review processes and automated verification tools in kernel development, particularly for interrupt handling and callback mechanisms that operate at the most privileged system levels.