patch 'net/mlx5: fix uninitialized skip count' has been queued to stable release 24.11.7

[luca.boccassi at gmail.com]

Hi,

FYI, your patch has been queued to stable release 24.11.7

Note it hasn't been pushed to http://dpdk.org/browse/dpdk-stable yet.
It will be pushed if I get no objections before 06/13/26. So please
shout if anyone has objections.

Also note that after the patch there's a diff of the upstream commit vs the
patch applied to the branch. This will indicate if there was any rebasing
needed to apply to the stable branch. If there were code changes for rebasing
(ie: not only metadata diffs), please double check that the rebase was
correctly done.

Queued patches are on a temporary branch at:
https://github.com/bluca/dpdk-stable

This queued commit can be viewed at:
https://github.com/bluca/dpdk-stable/commit/edaf821280b1ceb953bfcb9f0abc27176363c029

Thanks.

Luca Boccassi

---
>From edaf821280b1ceb953bfcb9f0abc27176363c029 Mon Sep 17 00:00:00 2001
From: Kiran Vedere <kiranv at nvidia.com>
Date: Fri, 15 May 2026 14:33:58 +0200
Subject: [PATCH] net/mlx5: fix uninitialized skip count

[ upstream commit 2a19d07ece8f3866176ea4dd6f1e1bb813eadef3 ]

mlx5_rx_poll_len() may return MLX5_ERROR_CQE_MASK when
mlx5_rx_err_handle() reports MLX5_CQE_STATUS_HW_OWN while the Rx queue
is in IGNORE error state. In this HW_OWN case mlx5_rx_err_handle()
does not necessarily write to *skip_cnt, yet the caller (mlx5_rx_burst)
unconditionally uses skip_cnt to advance rq_ci.

This can cause rq_ci to jump by an undefined value, desynchronizing the
RQ and CQ rings and leading to persistent bad packet delivery until the
queue is reset.

Fixes: aa67ed308458 ("net/mlx5: ignore non-critical syndromes for Rx queue")

Signed-off-by: Kiran Vedere <kiranv at nvidia.com>
Acked-by: Dariusz Sosnowski <dsosnowski at nvidia.com>
---
 drivers/net/mlx5/mlx5_rx.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/mlx5/mlx5_rx.c b/drivers/net/mlx5/mlx5_rx.c
index 806e3e7484..17545e3d73 100644
--- a/drivers/net/mlx5/mlx5_rx.c
+++ b/drivers/net/mlx5/mlx5_rx.c
@@ -1050,7 +1050,7 @@ mlx5_rx_burst(void *dpdk_rxq, struct rte_mbuf **pkts, uint16_t pkts_n)
 	int len = 0; /* keep its value across iterations. */
 
 	while (pkts_n) {
-		uint16_t skip_cnt;
+		uint16_t skip_cnt = 0;
 		unsigned int idx = rq_ci & wqe_mask;
 		volatile struct mlx5_wqe_data_seg *wqe =
 			&((volatile struct mlx5_wqe_data_seg *)rxq->wqes)[idx];
@@ -1496,7 +1496,7 @@ mlx5_rx_burst_mprq(void *dpdk_rxq, struct rte_mbuf **pkts, uint16_t pkts_n)
 		uint16_t strd_cnt;
 		uint16_t strd_idx;
 		uint32_t byte_cnt;
-		uint16_t skip_cnt;
+		uint16_t skip_cnt = 0;
 		volatile struct mlx5_mini_cqe8 *mcqe = NULL;
 		enum mlx5_rqx_code rxq_code;
 
-- 
2.47.3

---
  Diff of the applied patch vs upstream commit (please double-check if non-empty:
---
--- -	2026-06-11 14:20:04.166039680 +0100
+++ 0072-net-mlx5-fix-uninitialized-skip-count.patch	2026-06-11 14:20:01.282747635 +0100
@@ -1 +1 @@
-From 2a19d07ece8f3866176ea4dd6f1e1bb813eadef3 Mon Sep 17 00:00:00 2001
+From edaf821280b1ceb953bfcb9f0abc27176363c029 Mon Sep 17 00:00:00 2001
@@ -5,0 +6,2 @@
+[ upstream commit 2a19d07ece8f3866176ea4dd6f1e1bb813eadef3 ]
+
@@ -17 +18,0 @@
-Cc: stable at dpdk.org
@@ -26 +27 @@
-index 9812bc7929..ce50087b70 100644
+index 806e3e7484..17545e3d73 100644
@@ -29,2 +30,2 @@
-@@ -1054,7 +1054,7 @@ mlx5_rx_burst(void *dpdk_rxq, struct rte_mbuf **pkts, uint16_t pkts_n)
- 	uint32_t data_seg_len = 0;
+@@ -1050,7 +1050,7 @@ mlx5_rx_burst(void *dpdk_rxq, struct rte_mbuf **pkts, uint16_t pkts_n)
+ 	int len = 0; /* keep its value across iterations. */
@@ -38 +39 @@
-@@ -1532,7 +1532,7 @@ mlx5_rx_burst_mprq(void *dpdk_rxq, struct rte_mbuf **pkts, uint16_t pkts_n)
+@@ -1496,7 +1496,7 @@ mlx5_rx_burst_mprq(void *dpdk_rxq, struct rte_mbuf **pkts, uint16_t pkts_n)