[iot] [coverity] Fix null dereferenced issues

Fix the null dereferenced issues from converity scan results.
issue id:
  3618300:Dereference after null check
  3618364:Dereference after null check
  3618463:Dereference after null check
  3618470:Explicit null dereferenced
  3618520:Dereference after null check

Test: issue fixed by converity scan.

Change-Id: I577ed094a1f9b493de61b84827c0e1157a4fbd2f
Signed-off-by: Luo Ji <ji.luo@nxp.com>

1 files changed, 5 insertions, 2 deletions

diff --git a/net/net.c b/net/net.c
index 4259c9e321..12951102c1 100644
--- a/net/net.c
+++ b/net/net.c
@@ -215,8 +215,11 @@ static int on_bootfile(const char *name, const char *value, enum env_op op,
 	switch (op) {
 	case env_op_create:
 	case env_op_overwrite:
-		copy_filename(net_boot_file_name, value,
-			      sizeof(net_boot_file_name));
+		if (value == NULL)
+			return -1;
+		else
+			copy_filename(net_boot_file_name, value,
+				      sizeof(net_boot_file_name));
 		break;
 	default:
 		break;