Use-After-Free Vulnerability in Linux Kernel nilfs2 Module

CVE-2023-53608

What is CVE-2023-53608?

A use-after-free vulnerability exists within the nilfs2 module of the Linux kernel, specifically in the handling of the nilfs_segctor_thread(). This issue arises when the finalization of the thread can race against the termination of that same thread, potentially leading to memory corruption. The problem occurs when the 'sc_task' member of the struct nilfs_sc_info is set to NULL after the thread has completed its tasks, but before it can notify the terminating thread. This scenario may allow nilfs_segctor_kill_thread() to access and deallocate the struct before the notification occurs, risking system stability and security. The vulnerability has been remediated by implementing a spinlock to protect the critical assignment and notification sequence, effectively eliminating the race condition.

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