irda: validate peer name and attribute lengths

Length fields provided by a peer for names and attributes may be longer
than the destination array sizes.  Validate lengths to prevent stack
buffer overflows.

Signed-off-by: Dan Rosenberg <drosenberg@vsecurity.com>
Cc: stable@kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>

net/irda/iriap.c

@@ -656,10 +656,16 @@ static void iriap_getvaluebyclass_indication(struct iriap_cb *self,
 	n = 1;
 
 	name_len = fp[n++];
+
+	IRDA_ASSERT(name_len < IAS_MAX_CLASSNAME + 1, return;);
+
 	memcpy(name, fp+n, name_len); n+=name_len;
 	name[name_len] = '\0';
 
 	attr_len = fp[n++];
+
+	IRDA_ASSERT(attr_len < IAS_MAX_ATTRIBNAME + 1, return;);
+
 	memcpy(attr, fp+n, attr_len); n+=attr_len;
 	attr[attr_len] = '\0';