In the Linux kernel, the following vulnerability has been resolved: x86/mm: Fix pti_clone_pgtable() alignment assumption Guenter reported dodgy crashes on an i386-nosmp build using GCC-11 that had the form of endless traps until entry stack exhaust and then #DF from the stack guard. It turned out that pti_clone_pgtable() had alignment assumptions on the start address, notably it hard assumes start is PMD aligned. This is true on x86_64, but very much not true on i386. These assumptions can cause the end condition to malfunction, leading to a 'short' clone. Guess what happens when the user mapping has a short copy of the entry text? Use the correct increment form for addr to avoid alignment assumptions.
Upstream advisory: https://lore.kernel.org/linux-cve-announce/2024090415-CVE-2024-44965-d41d@gregkh/T
This issue has been addressed in the following products: Red Hat Enterprise Linux 9 Via RHSA-2024:9315 https://access.redhat.com/errata/RHSA-2024:9315