CVE-2026-74510 in Linux
Summary
by MITRE • 08/15/2026
In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: mgmt: fix UAF in pair command cancellation
The pairing completion and authentication failure callbacks look up the pending MGMT_OP_PAIR_DEVICE command by walking hdev->mgmt_pending. The lookup returned a command that was still linked on the shared pending list, without keeping mgmt_pending_lock held for the later dereference and removal.
A concurrent MGMT_OP_CANCEL_PAIR_DEVICE request can remove and free the same pending command before the callback uses it. The reverse race is also possible when cancel_pair_device() gets a command from pending_find() and a callback removes it before the cancel path dereferences it. This can lead to a use-after-free and a second list_del().
Make the pairing lookup helpers transfer ownership of the pending command by removing it from hdev->mgmt_pending while holding mgmt_pending_lock. The callbacks and cancel path then complete the command and free it directly, so racing paths cannot find or free the same command again. Take a temporary hci_conn reference in cancel_pair_device() because the command completion drops the reference stored in the pending command.
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Analysis
by VulDB Data Team • 08/15/2026
This vulnerability resides in the Linux kernel's Bluetooth management subsystem where a use-after-free condition can occur during pairing command cancellation operations. The flaw manifests when the system processes pairing completion and authentication failure callbacks that traverse the hdev->mgmt_pending list to locate pending MGMT_OP_PAIR_DEVICE commands. The core issue stems from insufficient locking mechanisms during the command lookup process, specifically the failure to maintain mgmt_pending_lock coverage throughout the entire dereference and removal sequence.
The race condition emerges from concurrent execution paths where a pairing completion callback may access a command that has been simultaneously removed by a MGMT_OP_CANCEL_PAIR_DEVICE request. This creates a scenario where one code path retrieves a command pointer from the shared pending list, while another path concurrently removes and frees the same memory location. The vulnerability is classified as a use-after-free condition under CWE-416, representing a classic memory safety issue where freed memory is accessed beyond its intended lifecycle.
The operational impact of this vulnerability extends across all Linux systems utilizing Bluetooth functionality with kernel versions containing the affected code paths. An attacker could potentially exploit this race condition to achieve arbitrary code execution or system instability by manipulating concurrent pairing and cancellation operations. The security implications are particularly concerning in embedded systems, mobile devices, and IoT platforms where Bluetooth connectivity is prevalent.
The fix implements a comprehensive ownership transfer mechanism for pending command lookups by ensuring that all command retrieval operations remove the command from the hdev->mgmt_pending list while maintaining mgmt_pending_lock throughout the process. This approach prevents both race conditions by guaranteeing exclusive access to each command during its processing lifecycle. The solution also requires taking temporary hci_conn references in the cancel_pair_device() function to maintain proper reference counting, as the command completion path subsequently drops references stored within the pending command structure.
This remediation aligns with established security practices for concurrent data structure manipulation and follows ATT&CK technique T1068 which involves exploiting weaknesses in system design or implementation. The fix prevents attackers from leveraging timing-based race conditions to corrupt memory management structures, thereby maintaining system integrity during critical Bluetooth pairing operations. The solution represents a defensive programming approach that eliminates the window of vulnerability through proper lock management and resource ownership semantics.
The vulnerability demonstrates how seemingly minor concurrency issues can lead to critical security implications in kernel space operations, highlighting the importance of thorough lock acquisition patterns in multi-threaded environments. This fix exemplifies best practices for preventing use-after-free conditions in kernel modules and reinforces the need for careful consideration of shared data structures in real-time operating system components. The mitigation strategy directly addresses the root cause by ensuring atomic command retrieval and removal operations while maintaining proper reference counting mechanisms throughout the pairing lifecycle management process.