sound/oss/opl3: validate voice and channel indexes

User-controllable indexes for voice and channel values may cause reading and writing beyond the bounds of their respective arrays, leading to potentially exploitable memory corruption. Validate these indexes. Signed-off-by: Dan Rosenberg <[email protected]> Cc: [email protected] Signed-off-by: Takashi Iwai <[email protected]>
redpig · Mar 23, 2011 · 4d00135 · 4d00135
1 parent b769f49
commit 4d00135
Showing 1 changed file with 13 additions and 2 deletions.
diff --git a/sound/oss/opl3.c b/sound/oss/opl3.c
@@ -845,6 +845,10 @@ static int opl3_load_patch(int dev, int format, const char __user *addr,
 
 static void opl3_panning(int dev, int voice, int value)
 {
+
+	if (voice < 0 || voice >= devc->nr_voice)
+		return;
+
 	devc->voc[voice].panning = value;
 }
 
@@ -1062,8 +1066,15 @@ static int opl3_alloc_voice(int dev, int chn, int note, struct voice_alloc_info
 
 static void opl3_setup_voice(int dev, int voice, int chn)
 {
-	struct channel_info *info =
-	&synth_devs[dev]->chn_info[chn];
+	struct channel_info *info;
+
+	if (voice < 0 || voice >= devc->nr_voice)
+		return;
+
+	if (chn < 0 || chn > 15)
+		return;
+
+	info = &synth_devs[dev]->chn_info[chn];
 
 	opl3_set_instr(dev, voice, info->pgm_num);