[vlc-commits] spu: rss: initialize title strings with non NULL pointer

[Daniel Glaas]

vlc | branch: master | Daniel Glaas <daniel.glaas at freenet.de> | Wed Aug 19 19:55:02 2020 +0200| [41bb65aeb28da1f72382ef036ad0846116c945d8] | committer: Thomas Guillem

spu: rss: initialize title strings with non NULL pointer

If no valid title could be parsed out of an RSS feed, the segmentation fault
caused VLC to crash. The reason therefore was that the expected pointers to the
char buffers containing the titles were NULL pointers.

This commit initializes the titles of both the feeds and all items with a zero
string.

Additionally, the check whether already a title was found during parsing is
removed as it is not reasonable why a RSS stream should provide several title
tags for one item.

> http://git.videolan.org/gitweb.cgi/vlc.git/?a=commit;h=41bb65aeb28da1f72382ef036ad0846116c945d8
---

 modules/spu/rss.c | 18 +++++++++++-------
 1 file changed, 11 insertions(+), 7 deletions(-)

diff --git a/modules/spu/rss.c b/modules/spu/rss.c
index 49894a4c98..a04d9275e4 100644
--- a/modules/spu/rss.c
+++ b/modules/spu/rss.c
@@ -71,6 +71,8 @@ static const char *const ppsz_color_descriptions[] = {
                N_("Teal"), N_("Lime"), N_("Purple"), N_("Navy"), N_("Blue"),
                N_("Aqua") };
 
+static const char s_init_title[] = "";
+
 /*****************************************************************************
  * filter_sys_t: rss filter descriptor
  *****************************************************************************/
@@ -660,7 +662,7 @@ static int ParseUrls( filter_t *p_filter, char *psz_urls )
 
         p_feed->i_items = 0;
         p_feed->p_items = NULL;
-        p_feed->psz_title = NULL;
+        p_feed->psz_title = (char *)s_init_title;
         p_feed->psz_link = NULL;
         p_feed->psz_description = NULL;
         p_feed->psz_image = NULL;
@@ -711,7 +713,7 @@ static bool ParseFeed( filter_t *p_filter, xml_reader_t *p_xml_reader,
                 p_feed->i_items++;
                 p_feed->p_items = xrealloc( p_feed->p_items,
                                      p_feed->i_items * sizeof( rss_item_t ) );
-                p_feed->p_items[p_feed->i_items-1].psz_title = NULL;
+                p_feed->p_items[p_feed->i_items-1].psz_title = (char *)s_init_title;
                 p_feed->p_items[p_feed->i_items-1].psz_description = NULL;
                 p_feed->p_items[p_feed->i_items-1].psz_link = NULL;
             }
@@ -803,7 +805,7 @@ static bool ParseFeed( filter_t *p_filter, xml_reader_t *p_xml_reader,
             {
                 rss_item_t *p_item = p_feed->p_items+i_item;
                 /* rss/atom */
-                if( !strcmp( psz_eltname, "title" ) && !p_item->psz_title )
+                if( !strcmp( psz_eltname, "title" ) && p_item->psz_title == s_init_title )
                 {
                     p_item->psz_title = psz_eltvalue;
                 }
@@ -835,7 +837,7 @@ static bool ParseFeed( filter_t *p_filter, xml_reader_t *p_xml_reader,
             else
             {
                 /* rss/atom */
-                if( !strcmp( psz_eltname, "title" ) && !p_feed->psz_title )
+                if( !strcmp( psz_eltname, "title" ) && p_feed->psz_title == s_init_title )
                 {
                     p_feed->psz_title = psz_eltvalue;
                 }
@@ -904,7 +906,7 @@ static rss_feed_t* FetchRSS( filter_t *p_filter )
         rss_feed_t *p_old_feed = p_sys->p_feeds + i_feed;
 
         /* Initialize the structure */
-        p_feed->psz_title = NULL;
+        p_feed->psz_title = (char *)s_init_title;
         p_feed->psz_description = NULL;
         p_feed->psz_link = NULL;
         p_feed->psz_image = NULL;
@@ -970,12 +972,14 @@ static void FreeRSS( rss_feed_t *p_feeds, int i_feeds )
         for( int i_item = 0; i_item < p_feed->i_items; i_item++ )
         {
             rss_item_t *p_item = p_feed->p_items+i_item;
-            free( p_item->psz_title );
+            if( p_item->psz_title != s_init_title )
+                free( p_item->psz_title );
             free( p_item->psz_link );
             free( p_item->psz_description );
         }
         free( p_feed->p_items );
-        free( p_feed->psz_title);
+        if( p_feed->psz_title != s_init_title )
+            free( p_feed->psz_title );
         free( p_feed->psz_link );
         free( p_feed->psz_description );
         free( p_feed->psz_image );