Security Advisory
CVE-2025-39793
CVE vulnerability detail — eXtreme Datacenter Security Operations
Description
In the Linux kernel, the following vulnerability has been resolved: io_uring/memmap: cast nr_pages to size_t before shifting If the allocated size exceeds UINT_MAX, then its necessary to cast the mr->nr_pages value to size_t to prevent it from overflowing. In practice this isnt much of a concern as the required memory size will have been validated upfront, and accounted to the user. And > 4GB sizes will be necessary to make the lack of a cast a problem, which greatly exceeds normal user locked_vm settings that are generally in the kb to mb range. However, if root is used, then accounting isnt done, and then its possible to hit this issue.