x86, amd-ucode: Check UCODE_MAGIC before loading the container file

Signed-off-by: NBorislav Petkov <borislav.petkov@amd.com>
Signed-off-by: NAndreas Herrmann <andreas.herrmann3@amd.com>
LKML-Reference: <20091029134552.GC30802@alberich.amd.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

arch/x86/kernel/microcode_amd.c

@@ -317,6 +317,12 @@ static enum ucode_state request_microcode_fw(int cpu, struct device *device)
 		return UCODE_NFOUND;
 	}
 
+	if (*(u32 *)firmware->data != UCODE_MAGIC) {
+		printk(KERN_ERR "microcode: invalid UCODE_MAGIC (0x%08x)\n",
+		       *(u32 *)firmware->data);
+		return UCODE_ERROR;
+	}
+
 	ret = generic_load_microcode(cpu, firmware->data, firmware->size);
 
 	release_firmware(firmware);