+ mlx5 maintainers
Thank you for the patch.
On Wed, Jul 02, 2025 at 08:36:17AM -0400, Khadem Ullah wrote:
> 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: sta...@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
I tried these steps on v25.07-rc3 and the segfault does not reproduce for me.
rte_flow_create() correctly returns ENOTSUP for that case.
Similar case was segfaulting recently,
but it was fixed by this commit:
https://github.com/DPDK/dpdk/commit/c30b356a4d48542fe99c47aa470afc8cd1ced9f5
This specific fix is available from v25.03 and is included in v24.11.2
On other LTSes - v22.11.8 and v23.11.4 - segfault does not reproduce
for me as well. Either ENOTSUP or validation error is reported.
Which DPDK version are you using?
I see that the flow rule is created with transfer attribute.
Are you using a setup with switchdev enabled?
(https://docs.kernel.org/networking/device_drivers/ethernet/mellanox/mlx5/switchdev.html)
>
> This patch ensures proper handling of the meter action with
> transfer rule to prevent this crash.
>
> Signed-off-by: Khadem Ullah <14pwcse1...@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
>
Best regards,
Dariusz Sosnowski
