CVE-2024-44965

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> x86/mm: Fix pti_clone_pgtable() alignment assumption<br /> <br /> Guenter reported dodgy crashes on an i386-nosmp build using GCC-11<br /> that had the form of endless traps until entry stack exhaust and then<br /> #DF from the stack guard.<br /> <br /> It turned out that pti_clone_pgtable() had alignment assumptions on<br /> the start address, notably it hard assumes start is PMD aligned. This<br /> is true on x86_64, but very much not true on i386.<br /> <br /> These assumptions can cause the end condition to malfunction, leading<br /> to a &amp;#39;short&amp;#39; clone. Guess what happens when the user mapping has a<br /> short copy of the entry text?<br /> <br /> Use the correct increment form for addr to avoid alignment<br /> assumptions.