Kernel Vulnerability in Linux Affecting rcu/nocb Functionality

CVE-2025-38704

What is CVE-2025-38704?

A vulnerability exists in the Linux kernel that impacts the handling of rcu/nocb functionality during CPU online preparations. When a specific kernel thread pointer (rdp's->nocb_cb_kthread) is not created, it can lead to an invalid pointer access during subsequent operations. This occurs when an offline CPU's re-offload checks bypass certain conditional validations, risking access to an invalid memory pointer. This potentially compromises system stability and security, necessitating immediate attention and application of the relevant patches.

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