diff --git a/code/client/snd_mix.c b/code/client/snd_mix.c
index 7dbcfda33..cd8ea49c9 100644
--- a/code/client/snd_mix.c
+++ b/code/client/snd_mix.c
@@ -284,6 +284,9 @@ void S_SetVoiceAmplitudeFrom16( const sfx_t *sc, int sampleOffset, int count, in
 	for ( i = 0; i < count; i++ ) {
 		if ( sampleOffset >= SND_CHUNK_SIZE ) {
 			chunk = chunk->next;
+			if ( !chunk ) {
+				chunk = sc->soundData;
+			}
 			samples = chunk->sndChunk;
 			sampleOffset = 0;
 		}
@@ -528,6 +531,9 @@ static void S_PaintChannelFrom16_scalar( channel_t *ch, const sfx_t *sc, int cou
 
 			if (sampleOffset == SND_CHUNK_SIZE) {
 				chunk = chunk->next;
+				if ( !chunk ) {
+					chunk = sc->soundData;
+				}
 				samples = chunk->sndChunk;
 				sampleOffset = 0;
 			}
@@ -703,6 +709,9 @@ void S_PaintChannelFromMuLaw( channel_t *ch, sfx_t *sc, int count, int sampleOff
 			samples++;
 			if (chunk != NULL && samples == (byte *)chunk->sndChunk+(SND_CHUNK_SIZE*2)) {
 				chunk = chunk->next;
+				if ( !chunk ) {
+					chunk = sc->soundData;
+				}
 				samples = (byte *)chunk->sndChunk;
 			}
 		}
diff --git a/code/qcommon/common.c b/code/qcommon/common.c
index 04f0e03f0..c341a1eea 100644
--- a/code/qcommon/common.c
+++ b/code/qcommon/common.c
@@ -624,8 +624,18 @@ Com_StringContains
 */
 char *Com_StringContains( char *str1, char *str2, int casesensitive ) {
 	int len, i, j;
-
-	len = strlen( str1 ) - strlen( str2 );
+	size_t l1, l2;
+
+	l1 = strlen( str1 );
+	l2 = strlen( str2 );
+	if ( l2 > l1 ) {
+		// substring is longer than haystack; the loop below would
+		// not execute, but the unsigned subtraction would underflow
+		// before being truncated into int and produce indeterminate
+		// loop bounds. Bail explicitly.
+		return NULL;
+	}
+	len = (int)( l1 - l2 );
 	for ( i = 0; i <= len; i++, str1++ ) {
 		for ( j = 0; str2[j]; j++ ) {
 			if ( casesensitive ) {