From: Sami Kerola <kerolasa@iki.fi>
Date: Sat, 29 Feb 2020 08:51:53 +0000 (+0000)
Subject: libuuid: ensure variable is initialized [cppcheck]
X-Git-Tag: v2.36-rc1~160^2~2
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=3c92864ecd755286b8a743d8ac3388e67ae8598c;p=thirdparty%2Futil-linux.git

libuuid: ensure variable is initialized [cppcheck]

This fix has a little bit of a feel of making a static analyzer to be happy
instead of real progress.  If I read the preprocessor directives correctly
it should be impossible hit uninitialized variable.  Then again if a bug
creeps into these ifdef's in that case it is nice to have robust code that
doesn't immediately go wrong.

    libuuid/src/gen_uuid.c:200:20: error: Uninitialized variable: a [uninitvar]
       memcpy(node_id, a, 6);
                       ^
    libuuid/src/gen_uuid.c:197:8: error: Uninitialized variable: a [uninitvar]
      if (!a[0] && !a[1] && !a[2] && !a[3] && !a[4] && !a[5])
           ^

Signed-off-by: Sami Kerola <kerolasa@iki.fi>
---

diff --git a/libuuid/src/gen_uuid.c b/libuuid/src/gen_uuid.c
index 27c135db59..69f9591a46 100644
--- a/libuuid/src/gen_uuid.c
+++ b/libuuid/src/gen_uuid.c
@@ -136,7 +136,7 @@ static int get_node_id(unsigned char *node_id)
 	struct ifconf	ifc;
 	char buf[1024];
 	int		n, i;
-	unsigned char	*a;
+	unsigned char	*a = NULL;
 #ifdef HAVE_NET_IF_DL_H
 	struct sockaddr_dl *sdlp;
 #endif
@@ -194,7 +194,7 @@ static int get_node_id(unsigned char *node_id)
 #endif /* HAVE_NET_IF_DL_H */
 #endif /* SIOCGENADDR */
 #endif /* SIOCGIFHWADDR */
-		if (!a[0] && !a[1] && !a[2] && !a[3] && !a[4] && !a[5])
+		if (a == NULL || (!a[0] && !a[1] && !a[2] && !a[3] && !a[4] && !a[5]))
 			continue;
 		if (node_id) {
 			memcpy(node_id, a, 6);