[PATCH] efi_loader: image_loader: fix a Coverity check against array access

[AKASHI Takahiro]

Coverity detected:
  Using "&opt->CheckSum" as an array.  This might corrupt or misinterpret
  adjacent memory locations.

The code should work as far as a structure, IMAGE_OPTIONAL_HEADER(64) is
packed, but modify it in more logical form. Subsystem is a member next to
CheckSum.

Signed-off-by: AKASHI Takahiro <takahiro.akashi at linaro.org>
Reported-by: Coverity (CID 300339)
---
 lib/efi_loader/efi_image_loader.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/lib/efi_loader/efi_image_loader.c b/lib/efi_loader/efi_image_loader.c
index 2f270e5497aa..894103c6e4dd 100644
--- a/lib/efi_loader/efi_image_loader.c
+++ b/lib/efi_loader/efi_image_loader.c
@@ -293,12 +293,12 @@ bool efi_image_parse(void *efi, size_t len, struct efi_image_regions **regp,
 		efi_image_region_add(regs, efi, &opt->CheckSum, 0);
 		if (nt64->OptionalHeader.NumberOfRvaAndSizes <= ctidx) {
 			efi_image_region_add(regs,
-					     &opt->CheckSum + 1,
+					     &opt->Subsystem,
 					     efi + opt->SizeOfHeaders, 0);
 		} else {
 			/* Skip Certificates Table */
 			efi_image_region_add(regs,
-					     &opt->CheckSum + 1,
+					     &opt->Subsystem,
 					     &opt->DataDirectory[ctidx], 0);
 			efi_image_region_add(regs,
 					     &opt->DataDirectory[ctidx] + 1,
@@ -313,7 +313,7 @@ bool efi_image_parse(void *efi, size_t len, struct efi_image_regions **regp,
 		IMAGE_OPTIONAL_HEADER32 *opt = &nt->OptionalHeader;
 
 		efi_image_region_add(regs, efi, &opt->CheckSum, 0);
-		efi_image_region_add(regs, &opt->CheckSum + 1,
+		efi_image_region_add(regs, &opt->Subsystem,
 				     &opt->DataDirectory[ctidx], 0);
 		efi_image_region_add(regs, &opt->DataDirectory[ctidx] + 1,
 				     efi + opt->SizeOfHeaders, 0);
-- 
2.25.2