[PATCH] net/mlx5: fix crash when using meter in transfer flow

[Khadem Ullah <14pwcse1224@uetpeshawar.edu.pk>]

When creating a flow rule with the transfer attribute and a meter action,
the driver did not validate this combination and would crash due to
unsupported handling.

This patch adds explicit validation rejecting meter action in transfer
flows with an appropriate error message.

Fixes: 46a5e6bc6a85 ("net/mlx5: prepare meter flow tables")
Cc: stable@dpdk.org

Steps to reproduce:
1. Launch testpmd:
   ./build/app/dpdk-testpmd -l 0,1 -a <PCI BDF> -- -i --rxq=8 --txq=8

2. Inside testpmd:
   add port meter profile trtcm_rfc2698 0 0 5 10 50 100 1
   add port meter policy 0 0 g_actions mark id 3 / queue index 2 / end /
      y_actions mark id 7 / queue index 3 / end r_actions drop / end
   create port meter 0 0 0 0 yes 0xffff 0 y 0
3. flow create 0 group 0 ingress pattern eth / ipv4 / end actions
     jump group 1 / end
3. Following causes a segmentation fault:
   flow create 0 transfer ingress pattern eth / ipv4 /
      end actions meter mtr_id 0 / end

This patch ensures proper handling of the meter action with
transfer rule to prevent this crash.

Signed-off-by: Khadem Ullah <14pwcse1224@uetpeshawar.edu.pk>
---
 drivers/net/mlx5/mlx5_flow.c | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/drivers/net/mlx5/mlx5_flow.c b/drivers/net/mlx5/mlx5_flow.c
index 8db372123c..a7b793ef29 100644
--- a/drivers/net/mlx5/mlx5_flow.c
+++ b/drivers/net/mlx5/mlx5_flow.c
@@ -7993,7 +7993,17 @@ mlx5_flow_create(struct rte_eth_dev *dev,
 	struct rte_flow_attr *new_attr = (void *)(uintptr_t)attr;
 	uint32_t prio = attr->priority;
 	uintptr_t flow_idx;
-
+	if (attr && attr->transfer) {
+		const struct rte_flow_action *act;
+		for (act = actions; act && act->type != RTE_FLOW_ACTION_TYPE_END; ++act) {
+			if (act->type == RTE_FLOW_ACTION_TYPE_METER) {
+				rte_flow_error_set(error, ENOTSUP,
+					RTE_FLOW_ERROR_TYPE_ACTION, act,
+					"Meter action is not supported in transfer flows");
+				return NULL;
+			}
+		}
+	}
 	/*
 	 * If the device is not started yet, it is not allowed to created a
 	 * flow from application. PMD default flows and traffic control flows
-- 
2.43.0