From: Thomas Haller <thaller@redhat.com>
Date: Tue, 10 Jun 2014 15:50:09 +0000 (+0200)
Subject: route/link: fix dangling pointer after rtnl_link_get_ifalias(link, NULL)
X-Git-Tag: libnl3_2_25rc1~11^2~2
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=d7a9e74f82d136d1e3fa4e174e8b7ba9595ec9a9;p=libnl

route/link: fix dangling pointer after rtnl_link_get_ifalias(link, NULL)

Fixed bug that left a dangling pointer after clearing the ifalias
property. This happened when calling 'rtnl_link_get_ifalias(link, NULL)'
on a link that has already an ifalias set.

This can cause a crash and/or a double-free.

Error found by coverity.

Acked-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: Thomas Haller <thaller@redhat.com>
---

diff --git a/lib/route/link.c b/lib/route/link.c
index 65e42ec..3d31ffc 100644
--- a/lib/route/link.c
+++ b/lib/route/link.c
@@ -2102,11 +2102,13 @@ const char *rtnl_link_get_ifalias(struct rtnl_link *link)
 void rtnl_link_set_ifalias(struct rtnl_link *link, const char *alias)
 {
 	free(link->l_ifalias);
-	link->ce_mask &= ~LINK_ATTR_IFALIAS;
 
 	if (alias) {
 		link->l_ifalias = strdup(alias);
 		link->ce_mask |= LINK_ATTR_IFALIAS;
+	} else {
+		link->l_ifalias = NULL;
+		link->ce_mask &= ~LINK_ATTR_IFALIAS;
 	}
 }