CVE-2022-48749 in Linux
Summary
by MITRE • 06/20/2024
In the Linux kernel, the following vulnerability has been resolved:
drm/msm/dpu: invalid parameter check in dpu_setup_dspp_pcc
The function performs a check on the "ctx" input parameter, however, it is used before the check.
Initialize the "base" variable after the sanity check to avoid a possible NULL pointer dereference.
Addresses-Coverity-ID: 1493866 ("Null pointer dereference")
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Analysis
by VulDB Data Team • 08/09/2025
The vulnerability identified as CVE-2022-48749 resides within the Linux kernel's display subsystem, specifically in the drm/msm/dpu driver component responsible for managing display processing units on Qualcomm Snapdragon SoCs. This issue manifests as a classic null pointer dereference vulnerability that could potentially compromise system stability and security. The flaw affects the dpu_setup_dspp_pcc function which handles parameter validation for display processing color correction operations. The vulnerability represents a fundamental programming error that violates secure coding practices and could be exploited to cause system crashes or potentially enable privilege escalation depending on the execution context.
The technical flaw stems from improper parameter validation ordering within the dpu_setup_dspp_pcc function where the ctx input parameter undergoes a sanity check but is utilized before this validation occurs. This violates the principle of defensive programming and creates a window where a null pointer could be dereferenced if the validation fails or if the parameter is improperly initialized. The base variable initialization occurs before the parameter validation, creating a scenario where subsequent code attempts to access memory through a potentially uninitialized or null pointer reference. This type of vulnerability falls under CWE-476 which specifically addresses NULL pointer dereference conditions and represents a common class of software defects that can lead to system instability and potential security implications.
The operational impact of this vulnerability extends beyond simple system crashes to potentially enable more sophisticated attack vectors. When exploited, the null pointer dereference could cause the display subsystem to crash, leading to denial of service conditions that might affect user experience or system availability. In embedded systems or mobile devices where the display subsystem is critical for user interaction, such a vulnerability could be leveraged to cause persistent system instability. The vulnerability's exploitation potential increases when considering that display drivers often run with elevated privileges and may be accessible through various kernel interfaces, making this a potential entry point for privilege escalation attacks. According to ATT&CK framework, this vulnerability could map to T1059.003 for command and scripting interpreter usage or T1499.004 for network denial of service depending on the attack vector and exploitation method.
Mitigation strategies for CVE-2022-48749 should focus on immediate code fixes and broader security hardening measures. The primary fix involves reordering the parameter validation to occur before any usage of the ctx parameter, ensuring that the base variable is initialized only after successful validation. This simple but critical code reorganization prevents the null pointer dereference condition from occurring. System administrators should prioritize applying the kernel patches provided by the Linux kernel security team, as these patches directly address the flawed parameter handling logic. Additionally, implementing runtime protections such as kernel address space layout randomization and stack canaries can provide additional defense-in-depth measures. Regular security auditing of kernel subsystems, particularly driver components, should be conducted to identify similar parameter validation issues. Organizations should also consider implementing monitoring solutions that can detect anomalous behavior patterns that might indicate exploitation attempts, particularly in environments where display subsystem stability is critical for operations.