Concurrency Issue in Linux Kernel Bluetooth Component

CVE-2026-43019

What is CVE-2026-43019?

A vulnerability exists in the Bluetooth component of the Linux kernel, specifically in the handling of the hci_conn structure during the set_cig_params_sync process. The issue arises due to inadequate locking, where hci_conn can be freed concurrently if hdev lock is not properly acquired. This can lead to a Use After Free (UAF) condition, allowing potential exploitation by malicious actors. To mitigate this risk, it is essential to implement proper locking mechanisms to ensure that hci_conn is not modified or deleted concurrently, avoiding potential data corruption or system instability.

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