[dpdk-dev] [PATCH v2 05/13] net/enic: check for unsupported flow item types

[Hyong Youb Kim]

Currently a pattern with an unsupported item type causes segfault,
because the flow handler is using the type as an array index without
checking bounds. Add an explicit check for unsupported item types and
avoid out-of-bound accesses.

Fixes: 6ced137607d0 ("net/enic: flow API for NICs with advanced filters enabled")
Cc: stable at dpdk.org

Signed-off-by: Hyong Youb Kim <hyonkim at cisco.com>
Reviewed-by: John Daley <johndale at cisco.com>
---
 drivers/net/enic/enic_flow.c | 18 +++++++++++++++---
 1 file changed, 15 insertions(+), 3 deletions(-)

diff --git a/drivers/net/enic/enic_flow.c b/drivers/net/enic/enic_flow.c
index e12a6ec73..c60476c8c 100644
--- a/drivers/net/enic/enic_flow.c
+++ b/drivers/net/enic/enic_flow.c
@@ -40,6 +40,8 @@ struct enic_items {
 struct enic_filter_cap {
 	/** list of valid items and their handlers and attributes. */
 	const struct enic_items *item_info;
+	/* Max type in the above list, used to detect unsupported types */
+	enum rte_flow_item_type max_item_type;
 };
 
 /* functions for copying flow actions into enic actions */
@@ -257,12 +259,15 @@ static const struct enic_items enic_items_v3[] = {
 static const struct enic_filter_cap enic_filter_cap[] = {
 	[FILTER_IPV4_5TUPLE] = {
 		.item_info = enic_items_v1,
+		.max_item_type = RTE_FLOW_ITEM_TYPE_TCP,
 	},
 	[FILTER_USNIC_IP] = {
 		.item_info = enic_items_v2,
+		.max_item_type = RTE_FLOW_ITEM_TYPE_VXLAN,
 	},
 	[FILTER_DPDK_1] = {
 		.item_info = enic_items_v3,
+		.max_item_type = RTE_FLOW_ITEM_TYPE_VXLAN,
 	},
 };
 
@@ -946,7 +951,7 @@ item_stacking_valid(enum rte_flow_item_type prev_item,
  */
 static int
 enic_copy_filter(const struct rte_flow_item pattern[],
-		 const struct enic_items *items_info,
+		 const struct enic_filter_cap *cap,
 		 struct filter_v2 *enic_filter,
 		 struct rte_flow_error *error)
 {
@@ -969,7 +974,14 @@ enic_copy_filter(const struct rte_flow_item pattern[],
 		if (item->type == RTE_FLOW_ITEM_TYPE_VOID)
 			continue;
 
-		item_info = &items_info[item->type];
+		item_info = &cap->item_info[item->type];
+		if (item->type > cap->max_item_type ||
+		    item_info->copy_item == NULL) {
+			rte_flow_error_set(error, ENOTSUP,
+				RTE_FLOW_ERROR_TYPE_ITEM,
+				NULL, "Unsupported item.");
+			return -rte_errno;
+		}
 
 		/* check to see if item stacking is valid */
 		if (!item_stacking_valid(prev_item, item_info, is_first_item))
@@ -1423,7 +1435,7 @@ enic_flow_parse(struct rte_eth_dev *dev,
 		return -rte_errno;
 	}
 	enic_filter->type = enic->flow_filter_mode;
-	ret = enic_copy_filter(pattern, enic_filter_cap->item_info,
+	ret = enic_copy_filter(pattern, enic_filter_cap,
 				       enic_filter, error);
 	return ret;
 }
-- 
2.16.2