patch 'ring: fix use after free' has been queued to stable release 21.11.5

[Kevin Traynor]

Hi,

FYI, your patch has been queued to stable release 21.11.5

Note it hasn't been pushed to http://dpdk.org/browse/dpdk-stable yet.
It will be pushed if I get no objections before 07/25/23. 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/096ec31efd0f93756bbb4fe4d0876aef162a656c

Thanks.

Kevin

---
>From 096ec31efd0f93756bbb4fe4d0876aef162a656c Mon Sep 17 00:00:00 2001
From: Yunjian Wang <wangyunjian at huawei.com>
Date: Fri, 5 May 2023 14:48:34 +0800
Subject: [PATCH] ring: fix use after free

[ upstream commit ce4bd6e14aa693c80c5218f7d896c98b3b85b54a ]

After the memzone is freed, it is not removed from the 'rte_ring_tailq'.
If rte_ring_lookup is called at this time, it will cause a use-after-free
problem. This change prevents that from happening.

Fixes: 4e32101f9b01 ("ring: support freeing")

Signed-off-by: Yunjian Wang <wangyunjian at huawei.com>
Acked-by: Konstantin Ananyev <konstantin.v.ananyev at yandex.ru>
Reviewed-by: Honnappa Nagarahalli <honnappa.nagarahalli at arm.com>
---
 lib/ring/rte_ring.c | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/lib/ring/rte_ring.c b/lib/ring/rte_ring.c
index 6a94a038c4..40d29c1bc5 100644
--- a/lib/ring/rte_ring.c
+++ b/lib/ring/rte_ring.c
@@ -342,9 +342,4 @@ rte_ring_free(struct rte_ring *r)
 	}
 
-	if (rte_memzone_free(r->memzone) != 0) {
-		RTE_LOG(ERR, RING, "Cannot free memory\n");
-		return;
-	}
-
 	ring_list = RTE_TAILQ_CAST(rte_ring_tailq.head, rte_ring_list);
 	rte_mcfg_tailq_write_lock();
@@ -365,4 +360,7 @@ rte_ring_free(struct rte_ring *r)
 	rte_mcfg_tailq_write_unlock();
 
+	if (rte_memzone_free(r->memzone) != 0)
+		RTE_LOG(ERR, RING, "Cannot free memory\n");
+
 	rte_free(te);
 }
-- 
2.41.0

---
  Diff of the applied patch vs upstream commit (please double-check if non-empty:
---
--- -	2023-07-20 16:17:55.681995558 +0100
+++ 0004-ring-fix-use-after-free.patch	2023-07-20 16:17:54.415749503 +0100
@@ -1 +1 @@
-From ce4bd6e14aa693c80c5218f7d896c98b3b85b54a Mon Sep 17 00:00:00 2001
+From 096ec31efd0f93756bbb4fe4d0876aef162a656c Mon Sep 17 00:00:00 2001
@@ -5,0 +6,2 @@
+[ upstream commit ce4bd6e14aa693c80c5218f7d896c98b3b85b54a ]
+
@@ -11 +12,0 @@
-Cc: stable at dpdk.org
@@ -21 +22 @@
-index 8ed455043d..057d25ff6f 100644
+index 6a94a038c4..40d29c1bc5 100644
@@ -24 +25 @@
-@@ -334,9 +334,4 @@ rte_ring_free(struct rte_ring *r)
+@@ -342,9 +342,4 @@ rte_ring_free(struct rte_ring *r)
@@ -34 +35 @@
-@@ -357,4 +352,7 @@ rte_ring_free(struct rte_ring *r)
+@@ -365,4 +360,7 @@ rte_ring_free(struct rte_ring *r)