Deep Kernel Fix: Linux Closes a 5-Year-Old Flaw in x86 Memory Handling

A subtle but critical vulnerability was found in the Linux x86 page-fault handling logic (dating to the 5.8 merge window, 2020) where certain code paths could re-enable hardware interrupts inconsistently, creating an incorrect interrupt state; Intel engineer Cedric Xing identified the flaw and a robust fix—unconditionally disabling interrupts at a single point before returning to the low-level handler—has been merged into Linux 6.19 with backports planned.