Bluetooth Vulnerability in Linux Kernel Affects Multiple Devices

CVE-2025-21969

Summary

A vulnerability has been identified in the Linux kernel's Bluetooth subsystem, specifically within the L2CAP layer. This issue occurs due to a slab-use-after-free scenario in the l2cap_send_cmd function. When the HCI sync command releases the l2cap_conn, the associated work queue for receiving HCI data refers to a deallocated l2cap_conn, leading to potential memory access violations. To address this, a locking mechanism has been introduced to ensure proper synchronization between the connection release and data processing. This fix is crucial for safeguarding Bluetooth communications in various devices utilizing the affected kernel version.

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