CVE-2026-98774 in Linux
Summary
by MITRE • 10/18/2026
In the Linux kernel, the following vulnerability has been resolved:
rust_binder: cancel deferred work items in thread exit
If there are deferred work items on the thread todo list, then they are not cleaned up in the Thread::release() method. Thus, update the code to clean up the work items even if they are deferred.
This can happen if the thread dies while it has an active outgoing transaction.
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Analysis
by VulDB Data Team • 10/19/2026
The Linux kernel's binder driver serves as a critical inter-process communication mechanism used extensively by Android and other systems for managing service requests between processes. A recent resolution addresses a resource management flaw within the Rust implementation of this driver, specifically concerning the lifecycle handling of threads that have pending or deferred work items. The vulnerability arises from an oversight in the Thread::release() method, which is responsible for cleaning up resources when a thread terminates. Previously, if a thread possessed deferred work items on its todo list, these items were not properly cancelled or freed during the release process. This gap in cleanup logic means that memory and kernel structures associated with these pending tasks remain allocated even after the owning thread has ceased to exist, leading to potential resource leaks within the kernel space.
From a technical perspective, this issue is classified as an improper cleanup mechanism following object destruction, which aligns with CWE-404: Improper Shutdown or Release of Resources and potentially CWE-755: Improper Handling of Unexpected Operational State. The specific scenario where this flaw manifests involves a thread that dies while holding an active outgoing transaction. In such cases, the binder driver may have scheduled deferred work to handle aspects of the transaction completion asynchronously. Because the release routine failed to iterate through and cancel these deferred items, they remained queued in memory without any associated thread context to execute or clear them. This creates a situation where kernel memory is gradually consumed by orphaned work structures that are no longer reachable or executable but also not freed.
The operational impact of this vulnerability primarily centers on resource exhaustion rather than direct privilege escalation or remote code execution. Over time, as threads with deferred transactions exit without proper cleanup, the system may experience increased memory pressure due to leaked kernel allocations. In severe cases involving high-frequency transaction processing and frequent thread termination, this could contribute to a denial-of-service condition by depleting available kernel memory resources. While the immediate risk is limited to stability and performance degradation rather than security compromise, such leaks can destabilize long-running systems or embedded devices that rely on consistent binder communication for core functionality.
To mitigate this vulnerability, it is essential to ensure that all deferred work items are explicitly cancelled during thread teardown procedures. The fix involves updating the Thread::release() method to iterate through any pending deferred tasks and invoke their cancellation routines before freeing associated data structures. This ensures that no orphaned references remain in memory after a thread exits. For system administrators, applying the latest kernel patches is the primary remediation step. Additionally, developers utilizing the binder driver should audit their code paths for similar patterns where asynchronous work might outlive its creator and implement robust cleanup logic to prevent resource leaks. Adhering to strict lifecycle management practices ensures that all allocated resources are properly reclaimed upon thread termination, maintaining system stability and security posture.