Linux Kernel Vulnerability in FSCACHE Volume Creation Process

CVE-2024-56755

Summary

A vulnerability has been identified in the Linux kernel relating to the fscache_create_volume function, where a missing memory barrier between the operations of bit-clearing and process wake-up can lead to potential indefinite waiting issues. This flaw occurs during the volume creation process when multiple cookies interact, causing one process to remain in a waiting state even after the necessary bit-clearing action has been completed. The absence of a barrier does not guarantee the timely detection of this action by the waiting process, leading to a potential deadlock scenario. To resolve this issue, a change was implemented to introduce proper barriers that ensure synchronization between the clear and wake operations.

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