CVE-2025-38287 in Linux
Summary
by MITRE • 07/10/2025
In the Linux kernel, the following vulnerability has been resolved:
IB/cm: Drop lockdep assert and WARN when freeing old msg
The send completion handler can run after cm_id has advanced to another message. The cm_id lock is not needed in this case, but a recent change re-used cm_free_priv_msg(), which asserts that the lock is held and WARNs if the cm_id's currently outstanding msg is different than the one being freed.
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Analysis
by VulDB Data Team • 12/07/2025
The vulnerability described in CVE-2025-38287 resides within the Linux kernel's InfiniBand communication manager component, specifically affecting how message cleanup operations are handled during asynchronous communication processing. This issue manifests in the interaction between the send completion handler and the connection management identifier structure, creating a race condition scenario that can lead to system instability. The problem occurs when the completion handler executes after the connection management identifier has progressed to handle a subsequent message, resulting in improper state validation during memory deallocation operations.
The technical flaw stems from a recent code change that repurposed the cm_free_priv_msg() function for handling message cleanup operations. This function contains internal lockdep assertions that require the cm_id lock to be held during execution, yet the current implementation fails to account for scenarios where the send completion handler operates asynchronously with respect to the connection state advancement. The function performs a warning check that compares the currently outstanding message with the one being freed, and when these do not match due to the asynchronous nature of message processing, the system generates a WARN message and potentially disrupts normal operation flow. This represents a violation of proper lock ordering principles and concurrent access handling within kernel space.
The operational impact of this vulnerability extends beyond simple warning messages to potentially destabilize systems running InfiniBand networking components, particularly those utilizing high-performance communication patterns where asynchronous message handling is common. When the race condition occurs, the system may experience unexpected behavior during connection teardown or message cleanup phases, potentially leading to resource leaks, memory corruption, or in severe cases, system crashes that could affect availability of network services. The vulnerability is particularly concerning in production environments where InfiniBand infrastructure is critical for high-performance computing clusters, data center networking, or enterprise storage systems that rely on reliable message passing protocols.
Mitigation strategies for this vulnerability should focus on maintaining proper synchronization between asynchronous message handlers and connection management state transitions. The recommended approach involves modifying the cm_free_priv_msg() function to properly handle cases where the cm_id has advanced to a different message, either by removing the lockdep assertion when the lock is not actually required or by implementing appropriate conditional logic that accounts for the asynchronous nature of the completion handler. Security practitioners should also consider applying kernel updates that contain the specific fix for this race condition, ensuring that the updated code properly manages the relationship between message lifecycle management and connection state advancement. This vulnerability aligns with CWE-362, which addresses race conditions in concurrent programming, and may be categorized under ATT&CK technique T1547.001 for privilege escalation through kernel exploitation, though the immediate impact is more focused on system stability than direct security compromise.