[PATCH u-boot-mvebu v3 07/41] tools: kwbimage: Fix check for v0 extended header checksum

[Marek Behún]

From: Pali Rohár <p...@kernel.org>

Extended header checksum for v0 image is present only in the case when
extended header is present. Skip checksum validation if extended header
is not present.

Signed-off-by: Pali Rohár <p...@kernel.org>
Reviewed-by: Marek Behún <marek.be...@nic.cz>
Reviewed-by: Stefan Roese <s...@denx.de>
Reviewed-by: Chris Packham <judge.pack...@gmail.com>
Tested-by: Chris Packham <judge.pack...@gmail.com>
---
 tools/kwbimage.c | 18 +++++++++++-------
 1 file changed, 11 insertions(+), 7 deletions(-)

diff --git a/tools/kwbimage.c b/tools/kwbimage.c
index 724459fb8e..4d9d818538 100644
--- a/tools/kwbimage.c
+++ b/tools/kwbimage.c
@@ -1655,15 +1655,19 @@ static int kwbimage_verify_header(unsigned char *ptr, 
int image_size,
 
        /* Only version 0 extended header has checksum */
        if (image_version((void *)ptr) == 0) {
-               struct ext_hdr_v0 *ext_hdr;
+               struct main_hdr_v0 *mhdr = (struct main_hdr_v0 *)ptr;
 
-               ext_hdr = (struct ext_hdr_v0 *)
+               if (mhdr->ext & 0x1) {
+                       struct ext_hdr_v0 *ext_hdr;
+
+                       ext_hdr = (struct ext_hdr_v0 *)
                                (ptr + sizeof(struct main_hdr_v0));
-               checksum = image_checksum8(ext_hdr,
-                                          sizeof(struct ext_hdr_v0)
-                                          - sizeof(uint8_t));
-               if (checksum != ext_hdr->checksum)
-                       return -FDT_ERR_BADSTRUCTURE;
+                       checksum = image_checksum8(ext_hdr,
+                                                  sizeof(struct ext_hdr_v0)
+                                                  - sizeof(uint8_t));
+                       if (checksum != ext_hdr->checksum)
+                               return -FDT_ERR_BADSTRUCTURE;
+               }
        }
 
        return 0;
-- 
2.31.1