CVE-2022-49984 in Linux
Summary
by MITRE • 06/18/2025
In the Linux kernel, the following vulnerability has been resolved:
HID: steam: Prevent NULL pointer dereference in steam_{recv,send}_report
It is possible for a malicious device to forgo submitting a Feature Report. The HID Steam driver presently makes no prevision for this and de-references the 'struct hid_report' pointer obtained from the HID devices without first checking its validity. Let's change that.
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Analysis
by VulDB Data Team • 11/30/2025
The vulnerability CVE-2022-49984 represents a critical NULL pointer dereference flaw within the Linux kernel's HID Steam driver component. This issue specifically affects the steam_recv_report and steam_send_report functions where the driver fails to validate the legitimacy of HID report structures before attempting to access them. The vulnerability stems from the driver's assumption that all HID devices will consistently provide valid Feature Report data, creating a dangerous operational assumption that can be exploited by malicious hardware devices.
The technical implementation of this vulnerability occurs when a malicious HID device deliberately omits or fails to submit a Feature Report during communication with the Linux kernel's HID subsystem. Under normal circumstances, the HID driver expects to receive properly formatted report structures from connected devices, but when a device chooses to forgo submitting these reports, the driver's code path encounters a NULL pointer reference. This occurs because the driver retrieves a struct hid_report pointer from the HID device without first verifying whether the pointer contains valid data, leading to an immediate system crash or potential privilege escalation depending on the execution context.
From an operational security perspective, this vulnerability presents significant risks to Linux systems running kernel versions affected by this flaw, particularly those that support Steam controller functionality or other HID devices that rely on similar driver implementations. The attack vector requires physical access to the system or the ability to introduce malicious HID devices into the trusted environment, making it a hardware-level threat that can be exploited in scenarios involving untrusted peripheral devices. The potential impact includes system instability, denial of service conditions, and in some cases, the possibility of privilege escalation due to the kernel-level nature of the vulnerability.
The flaw aligns with CWE-476 which specifically addresses NULL pointer dereference vulnerabilities in software implementations. From an adversarial perspective, this vulnerability maps to several ATT&CK techniques including T1059 for system command execution and T1068 for privilege escalation through kernel exploits. The vulnerability's exploitation requires minimal technical sophistication but demands access to physical hardware or the ability to introduce malicious HID devices into the target system. Organizations should prioritize applying kernel updates that contain the patched HID Steam driver code, which implements proper NULL pointer validation before accessing HID report structures. Additionally, implementing hardware security measures such as USB device whitelisting and monitoring for anomalous HID device behavior can provide additional layers of protection against exploitation attempts targeting this vulnerability.