CVE-2025-39793

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 it's necessary to cast

the mr->nr_pages value to size_t to prevent it from overflowing. In

practice this isn't 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 isn't done, and

then it's possible to hit this issue.