[PATCH v3 6/9] x86/microcode/AMD: verify patch section type for every such section

From: Maciej S. Szmigiero
Date: Tue Mar 13 2018 - 17:07:09 EST


We should check whether the patch section currently being processed is
actually a patch section for each of them (not just the first one) in the
late loader verify_and_add_patch() function, just like the early loader
already does in parse_container() function.

Signed-off-by: Maciej S. Szmigiero <mail@xxxxxxxxxxxxxxxxxxxxx>
---
arch/x86/kernel/cpu/microcode/amd.c | 11 +++++------
1 file changed, 5 insertions(+), 6 deletions(-)

diff --git a/arch/x86/kernel/cpu/microcode/amd.c b/arch/x86/kernel/cpu/microcode/amd.c
index 0f78200f2f6c..3ad23e72c2b0 100644
--- a/arch/x86/kernel/cpu/microcode/amd.c
+++ b/arch/x86/kernel/cpu/microcode/amd.c
@@ -627,6 +627,11 @@ static int verify_and_add_patch(u8 family, u8 *fw, size_t leftover)
if (leftover < SECTION_HDR_SIZE + sizeof(*mc_hdr))
return leftover;

+ if (*(u32 *)fw != UCODE_UCODE_TYPE) {
+ pr_err("invalid type field in container file section header\n");
+ return -EINVAL;
+ }
+
patch_size = *(u32 *)(fw + 4);
if (patch_size > PATCH_MAX_SIZE) {
pr_err("patch size %u too large\n", patch_size);
@@ -704,12 +709,6 @@ static enum ucode_state __load_microcode_amd(u8 family, const u8 *data,
fw += offset;
leftover = size - offset;

- if (*(u32 *)fw != UCODE_UCODE_TYPE) {
- pr_err("invalid type field in container file section header\n");
- free_equiv_cpu_table();
- return ret;
- }
-
while (leftover) {
crnt_size = verify_and_add_patch(family, fw, leftover);
if (crnt_size < 0)