[dpdk-stable] [PATCH] net/mlx5: fix mbufs double free in vectorized MPRQ

[dpdk-stable] [PATCH] net/mlx5: fix mbufs double free in vectorized MPRQ

[Alexander Kozyrev]

Wrong index is used to find mbufs belonging to an application in
the rxq_free_elts_sprq() function in the case of vectorized MPRQ.
elts_ci points to the last allocated mbuf in this case, not rq_ci.
Use this field to avoid double free of mbuf and segmentation fault.

Fixes: 0f20acbf5ed ("net/mlx5: implement vectorized MPRQ burst")
Cc: stable@dpdk.org

Signed-off-by: Alexander Kozyrev <akozyrev@nvidia.com>
Acked-by: Viacheslav Ovsiienko <viacheslavo@nvidia.com>
---
 drivers/net/mlx5/mlx5_rxq.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/net/mlx5/mlx5_rxq.c b/drivers/net/mlx5/mlx5_rxq.c
index da7a8b3cd7..114f75b42b 100644
--- a/drivers/net/mlx5/mlx5_rxq.c
+++ b/drivers/net/mlx5/mlx5_rxq.c
@@ -346,7 +346,9 @@ rxq_free_elts_sprq(struct mlx5_rxq_ctrl *rxq_ctrl)
 		(1 << rxq->elts_n) * (1 << rxq->strd_num_n) :
 		(1 << rxq->elts_n);
 	const uint16_t q_mask = q_n - 1;
-	uint16_t used = q_n - (rxq->rq_ci - rxq->rq_pi);
+	uint16_t elts_ci = mlx5_rxq_mprq_enabled(&rxq_ctrl->rxq) ?
+		rxq->elts_ci : rxq->rq_ci;
+	uint16_t used = q_n - (elts_ci - rxq->rq_pi);
 	uint16_t i;
 
 	DRV_LOG(DEBUG, "port %u Rx queue %u freeing %d WRs",
@@ -359,8 +361,8 @@ rxq_free_elts_sprq(struct mlx5_rxq_ctrl *rxq_ctrl)
 	 */
 	if (mlx5_rxq_check_vec_support(rxq) > 0) {
 		for (i = 0; i < used; ++i)
-			(*rxq->elts)[(rxq->rq_ci + i) & q_mask] = NULL;
-		rxq->rq_pi = rxq->rq_ci;
+			(*rxq->elts)[(elts_ci + i) & q_mask] = NULL;
+		rxq->rq_pi = elts_ci;
 	}
 	for (i = 0; i != q_n; ++i) {
 		if ((*rxq->elts)[i] != NULL)
-- 
2.24.1

Re: [dpdk-stable] [PATCH] net/mlx5: fix mbufs double free in vectorized MPRQ

[Raslan Darawsheh]

Hi,

> -----Original Message-----
> From: Alexander Kozyrev <akozyrev@nvidia.com>
> Sent: Thursday, December 10, 2020 5:14 PM
> To: dev@dpdk.org
> Cc: stable@dpdk.org; Raslan Darawsheh <rasland@nvidia.com>; Slava
> Ovsiienko <viacheslavo@nvidia.com>; Matan Azrad <matan@nvidia.com>
> Subject: [PATCH] net/mlx5: fix mbufs double free in vectorized MPRQ
> 
> Wrong index is used to find mbufs belonging to an application in
> the rxq_free_elts_sprq() function in the case of vectorized MPRQ.
> elts_ci points to the last allocated mbuf in this case, not rq_ci.
> Use this field to avoid double free of mbuf and segmentation fault.
> 
> Fixes: 0f20acbf5ed ("net/mlx5: implement vectorized MPRQ burst")
> Cc: stable@dpdk.org
> 
> Signed-off-by: Alexander Kozyrev <akozyrev@nvidia.com>
> Acked-by: Viacheslav Ovsiienko <viacheslavo@nvidia.com>
> ---

Patch applied to next-net-mlx,

Kindest regards,
Raslan Darawsheh