ALSA: prevent heap corruption in snd_ctl_new()

[net-next-2.6.git] / sound / core / control.c

diff --git a/sound/core/control.c b/sound/core/control.c
index 070aab4901914870a0af43faef27e82e761acc32..45a818002d990f664cffadd066488a21c76fedd7 100644 (file)
--- a/sound/core/control.c
+++ b/sound/core/control.c
@@ -31,6 +31,7 @@
 
 /* max number of user-defined controls */
 #define MAX_USER_CONTROLS      32
+#define MAX_CONTROL_COUNT      1028
 
 struct snd_kctl_ioctl {
        struct list_head list;          /* list of all ioctls */
@@ -195,6 +196,10 @@ static struct snd_kcontrol *snd_ctl_new(struct snd_kcontrol *control,
        
        if (snd_BUG_ON(!control || !control->count))
                return NULL;
+
+       if (control->count > MAX_CONTROL_COUNT)
+               return NULL;
+
        kctl = kzalloc(sizeof(*kctl) + sizeof(struct snd_kcontrol_volatile) * control->count, GFP_KERNEL);
        if (kctl == NULL) {
                snd_printk(KERN_ERR "Cannot allocate control instance\n");