Linux Kernel Bluetooth Socket Race Condition Vulnerability

A race condition vulnerability has been identified in the Bluetooth subsystem of the Linux kernel, specifically within the socket management of HCI (Host Controller Interface) commands. This vulnerability arises from a conflict between the socket binding process and the iteration of socket write operations. The issue can lead to a use-after-free condition, where a command is prematurely freed before it can be sent, potentially causing memory corruption or other unintended behavior.

Impact

Exploitation of this vulnerability can lead to a use-after-free condition, allowing for memory corruption. Such conditions can often be exploited to execute arbitrary code or cause a denial-of-service by crashing the system.

Reproduction

The vulnerability can be reproduced by creating a Bluetooth socket and binding it to an HCI device. Once the socket is bound, initiate a write operation that sends a command through the socket. While the command is in the process of being sent, remove the command from the management pending list. This action will free the command's memory before the write operation completes, creating a use-after-free condition.

Remediation

The vulnerability has been addressed by synchronizing the socket binding and writing processes using a lock, preventing the race condition. Users should upgrade to the latest version of the Linux kernel where this fix has been applied.