Red Hat Security Advisory: kernel security update

Important

A flaw was found in the Linux kernel. When the kernel's real-time mutex (rtmutex) component performs a specific operation called 'proxy-lock rollback' during futex requeue, it incorrectly handles task pointers. This can lead to a 'Use-After-Free' (UAF) vulnerability, where the system attempts to use memory that has already been released. A local attacker could potentially exploit this to gain elevated privileges or execute unauthorized code.

CWE-825 - Expired Pointer Dereference

A flaw was found in the Linux kernel's futex (Fast Userspace Mutex) requeue mechanism. When a non-top waiter attempts to requeue a Priority Inheritance (PI) futex it already owns, a NULL pointer dereference can occur. This issue, specifically within the `remove_waiter()` function during a self-deadlock scenario, leads to a kernel crash, resulting in a Denial of Service (DoS).

CWE-476 - NULL Pointer Dereference

A flaw was found in the XFS filesystem. A race condition in the copy-on-write mechanism for reflinked files can cause writes to bypass the copy-on-write process and modify shared data blocks directly. As a result, data intended for a private copy may be written to the original shared location, corrupting the contents of other files that reference those blocks. A local attacker with read access to a file on an XFS filesystem with reflink enabled could exploit this flaw to corrupt files they do not have write access to, allowing content to be added to the target file. If properly exploited this vulnerability may lead to privilege escalations or arbitrary code execution.

CWE-362 - Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')