static int apply_microcode_early(struct ucode_cpu_info *uci, bool early)
{
	struct microcode_intel *mc_intel;
	unsigned int val[2];

	mc_intel = uci->mc;
	if (mc_intel == NULL)
		return 0;

	/* write microcode via MSR 0x79 */
	native_wrmsr(MSR_IA32_UCODE_WRITE,
	      (unsigned long) mc_intel->bits,
	      (unsigned long) mc_intel->bits >> 16 >> 16);
	native_wrmsr(MSR_IA32_UCODE_REV, 0, 0);

	/* As documented in the SDM: Do a CPUID 1 here */
	sync_core();

	/* get the current revision from MSR 0x8B */
	native_rdmsr(MSR_IA32_UCODE_REV, val[0], val[1]);
	if (val[1] != mc_intel->hdr.rev)
		return -1;

#ifdef CONFIG_X86_64
	/* Flush global tlb. This is precaution. */
	flush_tlb_early();
#endif
	uci->cpu_sig.rev = val[1];

	if (early)
		print_ucode(uci);
	else
		print_ucode_info(uci, mc_intel->hdr.date);

	return 0;
}

The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.