CVE-2024-35877 x86/mm/pat: fix VM_PAT handling in COW mappings

In the Linux kernel, the following vulnerability has been resolved: x86/mm/pat: fix VMPAT handling in COW mappings PAT handling won't do the right thing in COW mappings: the first PTE or, in fact, all PTEs can be replaced during write faults to point at anon folios. Reliably recovering the correc...