diff --git a/WHATS_NEW b/WHATS_NEW
index 2cce7dbd9..3bae8ac96 100644
--- a/WHATS_NEW
+++ b/WHATS_NEW
@@ -1,5 +1,6 @@
 Version 2.02.91 -
 ===================================
+  Add range test for device number in _scan_proc_dev().
   Use signed long for sysconf() call in cmirrord.
   Do not write in front of log buffer in print_log().
   Add boundary test for number of mirror devs and logs.
diff --git a/lib/filters/filter.c b/lib/filters/filter.c
index d36f21b7e..9d08a7a9e 100644
--- a/lib/filters/filter.c
+++ b/lib/filters/filter.c
@@ -226,7 +226,7 @@ static int _scan_proc_dev(const char *proc, const struct dm_config_node *cn)
 
 		/* If it's not a number it may be name of section */
 		line_maj = atoi(((char *) (line + i)));
-		if (!line_maj) {
+		if ((line_maj <= 0) || (line_maj >= NUMBER_OF_MAJORS)) {
 			blocksection = (line[i] == 'B') ? 1 : 0;
 			continue;
 		}