patch 'net/mlx5: fix double free in non-template flow destroy' has been queued to stable release 24.11.4

[Kevin Traynor]

Hi,

FYI, your patch has been queued to stable release 24.11.4

Note it hasn't been pushed to http://dpdk.org/browse/dpdk-stable yet.
It will be pushed if I get no objections before 11/05/25. 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/kevintraynor/dpdk-stable

This queued commit can be viewed at:
https://github.com/kevintraynor/dpdk-stable/commit/045c791fdba69e31ae54edf5fe95e9afd77aafc0

Thanks.

Kevin

---
>From 045c791fdba69e31ae54edf5fe95e9afd77aafc0 Mon Sep 17 00:00:00 2001
From: Maayan Kashani <mkashani at nvidia.com>
Date: Thu, 7 Aug 2025 13:00:26 +0300
Subject: [PATCH] net/mlx5: fix double free in non-template flow destroy

[ upstream commit 7867b5d7a545f32aa6e6c5b4b406434581a0166b ]

Avoid calling flow_hw_unregister_matcher twice when rule creation
fails due to insufficient memory, which previously caused
a use-after-free error detected by ASan.

As a preventative measure, clear released pointers in
flow_hw_destroy to avoid potential double-free issues.

Fixes: b2845d51c748 ("net/mlx5: support FDB in non-template flow")

Signed-off-by: Maayan Kashani <mkashani at nvidia.com>
Acked-by: Dariusz Sosnowski <dsosnowski at nvidia.com>
---
 drivers/net/mlx5/mlx5_flow_hw.c | 20 +++++++++++---------
 1 file changed, 11 insertions(+), 9 deletions(-)

diff --git a/drivers/net/mlx5/mlx5_flow_hw.c b/drivers/net/mlx5/mlx5_flow_hw.c
index 370f0374d6..0d0262a275 100644
--- a/drivers/net/mlx5/mlx5_flow_hw.c
+++ b/drivers/net/mlx5/mlx5_flow_hw.c
@@ -13834,9 +13834,4 @@ error:
 	if (hw_act.mhdr)
 		mlx5_free(hw_act.mhdr);
-	if (ret) {
-		/* release after actual error */
-		if ((*flow)->nt2hws && (*flow)->nt2hws->matcher)
-			flow_hw_unregister_matcher(dev, (*flow)->nt2hws->matcher);
-	}
 	return ret;
 }
@@ -13856,4 +13851,5 @@ flow_hw_destroy(struct rte_eth_dev *dev, struct rte_flow_hw *flow)
 		if (ret)
 			DRV_LOG(ERR, "bwc rule destroy failed");
+		flow->nt2hws->nt_rule = NULL;
 	}
 	flow->operation_type = MLX5_FLOW_HW_FLOW_OP_TYPE_DESTROY;
@@ -13870,16 +13866,22 @@ flow_hw_destroy(struct rte_eth_dev *dev, struct rte_flow_hw *flow)
 	  * , same as for DV.
 	  */
-	if (flow->nt2hws->flow_aux)
+	if (flow->nt2hws->flow_aux) {
 		mlx5_free(flow->nt2hws->flow_aux);
-
-	if (flow->nt2hws->rix_encap_decap)
+		flow->nt2hws->flow_aux = NULL;
+	}
+	if (flow->nt2hws->rix_encap_decap) {
 		flow_encap_decap_resource_release(dev, flow->nt2hws->rix_encap_decap);
+		flow->nt2hws->rix_encap_decap = 0;
+	}
 	if (flow->nt2hws->modify_hdr) {
 		MLX5_ASSERT(flow->nt2hws->modify_hdr->action);
 		mlx5_hlist_unregister(priv->sh->modify_cmds,
 				      &flow->nt2hws->modify_hdr->entry);
+		flow->nt2hws->modify_hdr = NULL;
 	}
-	if (flow->nt2hws->matcher)
+	if (flow->nt2hws->matcher) {
 		flow_hw_unregister_matcher(dev, flow->nt2hws->matcher);
+		flow->nt2hws->matcher = NULL;
+	}
 }
 
-- 
2.51.0

---
  Diff of the applied patch vs upstream commit (please double-check if non-empty:
---
--- -	2025-10-31 13:53:53.382234792 +0000
+++ 0036-net-mlx5-fix-double-free-in-non-template-flow-destro.patch	2025-10-31 13:53:52.096523556 +0000
@@ -1 +1 @@
-From 7867b5d7a545f32aa6e6c5b4b406434581a0166b Mon Sep 17 00:00:00 2001
+From 045c791fdba69e31ae54edf5fe95e9afd77aafc0 Mon Sep 17 00:00:00 2001
@@ -5,0 +6,2 @@
+[ upstream commit 7867b5d7a545f32aa6e6c5b4b406434581a0166b ]
+
@@ -14 +15,0 @@
-Cc: stable at dpdk.org
@@ -23 +24 @@
-index 0c3f554479..3da8d93454 100644
+index 370f0374d6..0d0262a275 100644
@@ -26 +27 @@
-@@ -14095,9 +14095,4 @@ error:
+@@ -13834,9 +13834,4 @@ error:
@@ -36 +37 @@
-@@ -14117,4 +14112,5 @@ flow_hw_destroy(struct rte_eth_dev *dev, struct rte_flow_hw *flow)
+@@ -13856,4 +13851,5 @@ flow_hw_destroy(struct rte_eth_dev *dev, struct rte_flow_hw *flow)
@@ -42 +43 @@
-@@ -14131,16 +14127,22 @@ flow_hw_destroy(struct rte_eth_dev *dev, struct rte_flow_hw *flow)
+@@ -13870,16 +13866,22 @@ flow_hw_destroy(struct rte_eth_dev *dev, struct rte_flow_hw *flow)
@@ -67,2 +68,2 @@
- 	if (flow->nt2hws->sample_release_ctx != NULL) {
- 		mlx5_nta_sample_mirror_entry_release(dev, flow->nt2hws->sample_release_ctx);
+ }
+