[PATCH 8/8] x86, microcode, intel: defend apply_microcode_intel with BUG_ON

[Henrique de Moraes Holschuh]

Microcode updates that requires an unknown loader should never reach the
apply_* functions (the code should have rejected it earlier).  Likewise
for an unknown microcode header layout.

Signed-off-by: Henrique de Moraes Holschuh <hmh@xxxxxxxxxx>
---
 arch/x86/kernel/cpu/microcode/intel.c       |    2 ++
 arch/x86/kernel/cpu/microcode/intel_early.c |    2 ++
 2 files changed, 4 insertions(+)

diff --git a/arch/x86/kernel/cpu/microcode/intel.c b/arch/x86/kernel/cpu/microcode/intel.c
index 40caef1..439681f 100644
--- a/arch/x86/kernel/cpu/microcode/intel.c
+++ b/arch/x86/kernel/cpu/microcode/intel.c
@@ -157,6 +157,8 @@ static int apply_microcode_intel(int cpu)
 	if (mc_intel == NULL)
 		return 0;
 
+	BUG_ON(mc_intel->hdr.hdrver != 1 || mc_intel->hdr.ldrver != 1);
+
 	/* Intel SDM vol 3A section 9.11.6, page 9-34 */
 	if (WARN_ONCE((unsigned long)(mc_intel->bits) % 16,
 		"microcode data incorrectly aligned"))
diff --git a/arch/x86/kernel/cpu/microcode/intel_early.c b/arch/x86/kernel/cpu/microcode/intel_early.c
index 994c59b..095db11 100644
--- a/arch/x86/kernel/cpu/microcode/intel_early.c
+++ b/arch/x86/kernel/cpu/microcode/intel_early.c
@@ -671,6 +671,8 @@ static int apply_microcode_early(struct mc_saved_data *mc_saved_data,
 	if (mc_intel == NULL)
 		return 0;
 
+	BUG_ON(mc_intel->hdr.hdrver != 1 || mc_intel->hdr.ldrver != 1);
+
 	mcu_data = mc_intel->bits;
 	aligned_mcu_data = mc_intel->bits;
 
-- 
1.7.10.4

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/