cve 2025 21999

About this tag
CVE-2025-21999 is a high-severity Linux kernel vulnerability involving a use-after-free race condition in the proc filesystem. The flaw occurs when a race between module removal (rmmod) and inode creation in proc_get_inode() allows the kernel to dereference a freed module pointer, potentially causing system crashes or memory corruption. The fix removes the unsafe dereference by saving necessary proc entry information ahead of registration. This vulnerability affects kernel availability and integrity, and administrators are advised to apply the upstream patch promptly.
  1. Linux Kernel CVE-2025-21999 Fix for Proc Use After Free Race

    A newly disclosed Linux-kernel vulnerability, tracked as CVE‑2025‑21999, patches a use‑after‑free (UAF) race in the proc filesystem: a race between module removal (rmmod) and inode creation in proc_get_inode() could let the kernel dereference a freed module pointer and crash or corrupt kernel...