Bugfix in kodakaio.c to fix segfault when non kodak scanners return unexpected data via avahi auto discovery

ChangeLog

@@ -1,3 +1,7 @@
+2013-10-14 Paul Newall <quandry@ntlworld.com>
+	* backend/kodakaio.c: fix bug #314301, 
+	Segfault when unexpected data returned by avahi auto discovery.
+
 2013-10-11 Rolf Bensch <rolf at bensch hyphen online dot de>
 	* backend/pixma_imageclass.c: Use generation variable instead of single
 	defines of scanner pid's. Now new scanners should work without extensive

backend/kodakaio.c

@@ -127,7 +127,7 @@ for ubuntu 12.10
 
 #define KODAKAIO_VERSION	02
 #define KODAKAIO_REVISION	4
-#define KODAKAIO_BUILD		6
+#define KODAKAIO_BUILD		7
 
 /* for usb (but also used for net though it's not required). */
 #define MAX_BLOCK_SIZE		32768
@@ -2184,6 +2184,7 @@ static void resolve_callback(
     AvahiLookupResultFlags flags,
     AVAHI_GCC_UNUSED void* userdata) {
 
+	AvahiStringList *vid_pair_list = NULL, *pid_pair_list = NULL;
 	char *pidkey, *pidvalue;
 	char *vidkey, *vidvalue;
 	size_t valuesize;
@@ -2204,20 +2205,40 @@ static void resolve_callback(
             avahi_address_snprint(a, sizeof(a), address);
 
 /* Output short for Kodak ESP */
-	DBG(min(10,DBG_AUTO), "%s:%u  %s  ", a,port,host_name);
-	avahi_string_list_get_pair(avahi_string_list_find(txt, "vid"), 
-		&vidkey, &vidvalue, &valuesize);
-	DBG(min(10,DBG_AUTO), "%s=%s  ", vidkey, vidvalue);
-	avahi_string_list_get_pair(avahi_string_list_find(txt, "pid"), 
-		&pidkey, &pidvalue, &valuesize);
-	DBG(min(10,DBG_AUTO), "%s=%s\n", pidkey, pidvalue);
+	DBG(min(10,DBG_AUTO), "%s:%u  %s\n", a,port,host_name);
 
+	vid_pair_list = avahi_string_list_find(txt, "vid");
+	if(vid_pair_list != NULL) {
+		avahi_string_list_get_pair(vid_pair_list, &vidkey, &vidvalue, &valuesize);
+		DBG(min(10,DBG_AUTO), "%s=%s  ", vidkey, vidvalue);
+	}
+	else	DBG(min(10,DBG_AUTO), "failed to find key vid\n");
+
+	pid_pair_list = avahi_string_list_find(txt, "pid");
+	if(pid_pair_list != NULL) {
+		avahi_string_list_get_pair(pid_pair_list, &pidkey, &pidvalue, &valuesize);
+		DBG(min(10,DBG_AUTO), "%s=%s\n", pidkey, pidvalue);
+	}
+	else	DBG(min(10,DBG_AUTO), "failed to find key pid\n");
+
+	if(pid_pair_list != NULL && vid_pair_list != NULL) {
 		ProcessAvahiDevice(name, vidvalue, pidvalue, a);
-	avahi_free(vidkey); avahi_free(vidvalue);
-	avahi_free(pidkey); avahi_free(pidvalue);
+	}
+	else DBG(min(10,DBG_AUTO), "didn't call ProcessAvahiDevice\n");
+
+	if(vid_pair_list != NULL) {
+		avahi_free(vidkey); 
+		avahi_free(vidvalue);
+		DBG(min(15,DBG_AUTO), "vidkey and vidvalue freed\n");
+	}
+	if(pid_pair_list != NULL) {
+		avahi_free(pidkey); 
+		avahi_free(pidvalue);
+		DBG(min(15,DBG_AUTO), "pidkey and pidvalue freed\n");
+	}
         }
     }
-
+    DBG(min(10,DBG_AUTO), "ending resolve_callback\n");
     avahi_service_resolver_free(r);
 }
 

doc/descriptions/kodakaio.desc

@@ -1,6 +1,6 @@
 :backend "kodakaio"
 :url "http://sourceforge.net/projects/cupsdriverkodak/" 
-:version "2.4.6"
+:version "2.4.7"
 :manpage "sane-kodakaio"
 :comment "Backend for Kodak AiO ESP and Hero printers. Also possibly Advent AWL10"
 :devicetype :scanner