CVE-2023-54249 in Linux
Summary
by MITRE • 12/30/2025
In the Linux kernel, the following vulnerability has been resolved:
bus: mhi: ep: Only send -ENOTCONN status if client driver is available
For the STOP and RESET commands, only send the channel disconnect status -ENOTCONN if client driver is available. Otherwise, it will result in null pointer dereference.
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Analysis
by VulDB Data Team • 04/27/2026
This vulnerability exists within the Linux kernel's Mobile High-speed Interface MHI (MHI) subsystem, specifically in the endpoint driver component that handles communication between host and device components. The flaw manifests when processing STOP and RESET commands through the MHI bus interface, where the system fails to properly validate whether a client driver is available before attempting to send a channel disconnect status notification. This represents a classic null pointer dereference scenario that can lead to system instability and potential exploitation by malicious actors.
The technical implementation issue stems from improper conditional logic within the MHI endpoint driver's command processing routine. When STOP and RESET commands are received, the kernel attempts to return -ENOTCONN status to indicate channel disconnection, but this operation occurs without verifying that a valid client driver context exists. This oversight creates a scenario where the system may attempt to dereference a null pointer when accessing driver-specific data structures or callback functions. The vulnerability aligns with CWE-476 which specifically addresses null pointer dereference conditions, and demonstrates poor defensive programming practices in kernel space where proper validation should precede all pointer operations.
The operational impact of this vulnerability extends beyond simple system crashes or hangs, as it can potentially enable privilege escalation or denial of service attacks within embedded systems that rely heavily on MHI for communication. Mobile devices, automotive systems, and industrial IoT platforms that utilize MHI for modem, network, or peripheral communication may be affected by this flaw. Attackers could potentially trigger the vulnerability through malformed STOP or RESET commands, leading to system panics, memory corruption, or unauthorized access to system resources. The vulnerability is particularly concerning in environments where MHI is used for critical communications, as it could be exploited to disrupt essential services or gain elevated privileges within the system.
Mitigation strategies should focus on implementing proper null pointer validation before sending status notifications and ensuring that all driver contexts are properly initialized before command processing begins. System administrators should apply kernel updates immediately to address this vulnerability, as the fix involves modifying the conditional logic to verify client driver availability before proceeding with status notifications. The ATT&CK framework categorizes this vulnerability under T1068, which involves exploiting legitimate credentials or system processes to gain access to system resources. Additionally, defensive measures should include monitoring for abnormal STOP and RESET command sequences and implementing proper input validation at the MHI bus interface level. Organizations using Linux-based systems with MHI support should conduct thorough security assessments to identify potential exploitation vectors and ensure proper patch management protocols are in place to prevent unauthorized access through this class of vulnerability.