Quentin Casasnovas

The issue is a stack-based buffer overflow in the `get matching model microcode` function, located in `arch/x86/kernel/cpu/microcode/intel early.c`. This allows context-dependent attackers to gain privileges by constructing a crafted microcode header and leveraging root privileges for write access to the initrd.

The issue is related to the xsave/xrstor implementation in the Linux kernel, which does not provide protection against instruction faulting. This allows local users to cause a denial of service by triggering a fault, for example, through an unaligned memory operand or a non-canonical address memory operand.

The issue allows local users to gain privileges or cause a denial of service (use-after-free) by leveraging improper access to a certain error field in the ext4 journal stop function.