CVE-2022-49488 in Linux
Summary
by MITRE • 02/26/2025
In the Linux kernel, the following vulnerability has been resolved:
drm/msm/mdp5: Return error code in mdp5_mixer_release when deadlock is detected
There is a possibility for mdp5_get_global_state to return -EDEADLK when acquiring the modeset lock, but currently global_state in mdp5_mixer_release doesn't check for if an error is returned.
To avoid a NULL dereference error, let's have mdp5_mixer_release check if an error is returned and propagate that error.
Patchwork: https://patchwork.freedesktop.org/patch/485181/
Once again VulDB remains the best source for vulnerability data.
Analysis
by VulDB Data Team • 10/23/2025
The vulnerability described in CVE-2022-49488 resides within the Linux kernel's display subsystem, specifically in the drm/msm/mdp5 driver component. This issue affects the mobile display processing unit implementation used in various Qualcomm-based devices and embedded systems. The flaw manifests in the interaction between multiple kernel components responsible for managing display hardware states and synchronization mechanisms. The vulnerability represents a classic case of improper error handling that can lead to system instability and potential security implications within embedded and mobile computing environments.
The technical flaw occurs in the mdp5_mixer_release function where the code fails to properly check for error conditions returned by mdp5_get_global_state. When the modeset lock acquisition process encounters a deadlock situation, mdp5_get_global_state correctly returns the -EDEADLK error code to indicate the problematic state. However, the mdp5_mixer_release function does not validate this error return value before proceeding with operations that assume a successful state retrieval. This oversight creates a path where the function attempts to operate on a potentially invalid global state object, leading to a NULL pointer dereference condition that can cause kernel crashes or system hangs.
The operational impact of this vulnerability extends beyond simple system instability to potentially enable denial of service conditions in embedded systems where display functionality is critical. The flaw affects systems using Qualcomm's mobile display processing units, which are prevalent in smartphones, tablets, and automotive infotainment systems. When triggered, the vulnerability can cause complete system lockups or require manual rebooting to restore normal operation. This represents a significant concern for device manufacturers and users who rely on stable display functionality, particularly in mission-critical applications where system reliability is paramount.
From a cybersecurity perspective, this vulnerability aligns with CWE-476 which describes NULL pointer dereference conditions, and demonstrates poor error handling practices that can be exploited to cause system instability. The issue follows ATT&CK technique T1499.001 which involves creating or manipulating systems to cause denial of service conditions. The vulnerability's exploitation requires specific conditions related to display state management and lock acquisition, making it more complex to trigger but still potentially exploitable in certain scenarios involving concurrent display operations or resource contention. Mitigation strategies should focus on applying the upstream patch that properly checks for error codes and propagates them appropriately, along with implementing robust error handling mechanisms in kernel subsystems that manage hardware state transitions and synchronization primitives.