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

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

1 files changed, 6 insertions, 0 deletions

diff --git a/arch/x86/kernel/microcode_amd.c b/arch/x86/kernel/microcode_amd.c
index 366baa179913..f4c538b681ca 100644
--- a/arch/x86/kernel/microcode_amd.c
+++ b/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);