tools: dumpimage: Fix crashing when trying to extract data from kwbimage

Trying to call the following command causes NULL pointer dereference in
strlen():
  ./tools/dumpimage -T kwbimage -o /tmp/out u-boot-spl.kwb

Fix it by checking whether params->imagename is non-NULL before calling
strlen().

Signed-off-by: Pali Rohár <pali@kernel.org>
Reviewed-by: Marek Behún <marek.behun@nic.cz>
Reviewed-by: Stefan Roese <sr@denx.de>

diff --git a/tools/kwbimage.c b/tools/kwbimage.c
index f3b16d9..5410df6 100644 (file)
--- a/tools/kwbimage.c
+++ b/tools/kwbimage.c
@@ -1867,7 +1867,7 @@ static int kwbimage_generate(struct image_tool_params *params,
  */
 static int kwbimage_check_params(struct image_tool_params *params)
 {
-       if (!strlen(params->imagename)) {
+       if (!params->imagename || !strlen(params->imagename)) {
                char *msg = "Configuration file for kwbimage creation omitted";
 
                fprintf(stderr, "Error:%s - %s\n", params->cmdname, msg);