msm: ipa2: Add check to validate rule_cnt

Add proper check to validate table rule count
which may lead to overflow error.

Change-Id: Idfa86878db49ad4803f8902c995eb4186a2d3523
Signed-off-by: Praveen Kurapati <pkurapat@codeaurora.org>

Author: Praveen Kurapati

drivers/platform/msm/ipa/ipa_v2/ipa_flt.c

@@ -1055,7 +1055,10 @@ static int __ipa_add_flt_rule(struct ipa_flt_tbl *tbl, enum ipa_ip_type ip,
 	} else {
 		list_add(&entry->link, &tbl->head_flt_rule_list);
 	}
-	tbl->rule_cnt++;
+	if (tbl->rule_cnt < IPA_RULE_CNT_MAX)
+		tbl->rule_cnt++;
+	else
+		return -EINVAL;
 	if (entry->rt_tbl)
 		entry->rt_tbl->ref_cnt++;
 	id = ipa_id_alloc(entry);

drivers/platform/msm/ipa/ipa_v2/ipa_i.h

@@ -204,6 +204,7 @@
 #define IPA2_ACTIVE_CLIENTS_LOG_LINE_LEN 96
 #define IPA2_ACTIVE_CLIENTS_LOG_HASHTABLE_SIZE 50
 #define IPA2_ACTIVE_CLIENTS_LOG_NAME_LEN 40
+#define IPA_RULE_CNT_MAX 512
 
 struct ipa2_active_client_htable_entry {
 	struct hlist_node list;

drivers/platform/msm/ipa/ipa_v2/ipa_rt.c

@@ -1077,7 +1077,10 @@ static int __ipa_add_rt_rule(enum ipa_ip_type ip, const char *name,
 		list_add_tail(&entry->link, &tbl->head_rt_rule_list);
 	else
 		list_add(&entry->link, &tbl->head_rt_rule_list);
-	tbl->rule_cnt++;
+	if (tbl->rule_cnt < IPA_RULE_CNT_MAX)
+		tbl->rule_cnt++;
+	else
+		return -EINVAL;
 	if (entry->hdr)
 		entry->hdr->ref_cnt++;
 	else if (entry->proc_ctx)