patch 'vhost: fix missing check on virtqueue access' has been queued to stable release 20.11.10

[luca.boccassi at gmail.com]

Hi,

FYI, your patch has been queued to stable release 20.11.10

Note it hasn't been pushed to http://dpdk.org/browse/dpdk-stable yet.
It will be pushed if I get no objections before 11/10/23. 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/bluca/dpdk-stable

This queued commit can be viewed at:
https://github.com/bluca/dpdk-stable/commit/6a3395ad5264dd58ced88f79997d3304f0de9f4f

Thanks.

Luca Boccassi

---
>From 6a3395ad5264dd58ced88f79997d3304f0de9f4f Mon Sep 17 00:00:00 2001
From: Maxime Coquelin <maxime.coquelin at redhat.com>
Date: Fri, 20 Oct 2023 10:47:59 +0200
Subject: [PATCH] vhost: fix missing check on virtqueue access

[ upstream commit 094c442cdbf1da3a19ae82ca7069fee8b3a43343 ]

Acquiring the access lock is not enough to ensure
virtqueue's metadata such as vring pointers are valid.

The access status must also be checked.

Fixes: 4e0de8dac853 ("vhost: protect vring access done by application")

Signed-off-by: Maxime Coquelin <maxime.coquelin at redhat.com>
Acked-by: David Marchand <david.marchand at redhat.com>
---
 lib/librte_vhost/vhost.c | 16 ++++++++++++++--
 1 file changed, 14 insertions(+), 2 deletions(-)

diff --git a/lib/librte_vhost/vhost.c b/lib/librte_vhost/vhost.c
index cb3ede8942..e62d797c89 100644
--- a/lib/librte_vhost/vhost.c
+++ b/lib/librte_vhost/vhost.c
@@ -1341,7 +1341,10 @@ rte_vhost_avail_entries(int vid, uint16_t queue_id)
 
 	rte_spinlock_lock(&vq->access_lock);
 
-	if (unlikely(!vq->enabled || vq->avail == NULL))
+	if (unlikely(!vq->access_ok))
+		goto out;
+
+	if (unlikely(!vq->enabled))
 		goto out;
 
 	ret = *(volatile uint16_t *)&vq->avail->idx - vq->last_used_idx;
@@ -1433,9 +1436,15 @@ rte_vhost_enable_guest_notification(int vid, uint16_t queue_id, int enable)
 
 	rte_spinlock_lock(&vq->access_lock);
 
+	if (unlikely(!vq->access_ok)) {
+		ret = -1;
+		goto out_unlock;
+	}
+
 	vq->notif_enable = enable;
 	ret = vhost_enable_guest_notification(dev, vq, enable);
 
+out_unlock:
 	rte_spinlock_unlock(&vq->access_lock);
 
 	return ret;
@@ -1495,7 +1504,10 @@ rte_vhost_rx_queue_count(int vid, uint16_t qid)
 
 	rte_spinlock_lock(&vq->access_lock);
 
-	if (unlikely(vq->enabled == 0 || vq->avail == NULL))
+	if (unlikely(!vq->access_ok))
+		goto out;
+
+	if (unlikely(!vq->enabled))
 		goto out;
 
 	ret = *((volatile uint16_t *)&vq->avail->idx) - vq->last_avail_idx;
-- 
2.39.2

---
  Diff of the applied patch vs upstream commit (please double-check if non-empty:
---
--- -	2023-11-08 19:23:52.275363126 +0000
+++ 0007-vhost-fix-missing-check-on-virtqueue-access.patch	2023-11-08 19:23:51.733395465 +0000
@@ -1 +1 @@
-From 094c442cdbf1da3a19ae82ca7069fee8b3a43343 Mon Sep 17 00:00:00 2001
+From 6a3395ad5264dd58ced88f79997d3304f0de9f4f Mon Sep 17 00:00:00 2001
@@ -5,0 +6,2 @@
+[ upstream commit 094c442cdbf1da3a19ae82ca7069fee8b3a43343 ]
+
@@ -12 +13,0 @@
-Cc: stable at dpdk.org
@@ -17 +18 @@
- lib/vhost/vhost.c | 16 ++++++++++++++--
+ lib/librte_vhost/vhost.c | 16 ++++++++++++++--
@@ -20,5 +21,5 @@
-diff --git a/lib/vhost/vhost.c b/lib/vhost/vhost.c
-index b438330063..43173c9eee 100644
---- a/lib/vhost/vhost.c
-+++ b/lib/vhost/vhost.c
-@@ -1420,7 +1420,10 @@ rte_vhost_avail_entries(int vid, uint16_t queue_id)
+diff --git a/lib/librte_vhost/vhost.c b/lib/librte_vhost/vhost.c
+index cb3ede8942..e62d797c89 100644
+--- a/lib/librte_vhost/vhost.c
++++ b/lib/librte_vhost/vhost.c
+@@ -1341,7 +1341,10 @@ rte_vhost_avail_entries(int vid, uint16_t queue_id)
@@ -26 +27 @@
- 	rte_rwlock_write_lock(&vq->access_lock);
+ 	rte_spinlock_lock(&vq->access_lock);
@@ -36 +37 @@
-@@ -1512,9 +1515,15 @@ rte_vhost_enable_guest_notification(int vid, uint16_t queue_id, int enable)
+@@ -1433,9 +1436,15 @@ rte_vhost_enable_guest_notification(int vid, uint16_t queue_id, int enable)
@@ -38 +39 @@
- 	rte_rwlock_write_lock(&vq->access_lock);
+ 	rte_spinlock_lock(&vq->access_lock);
@@ -49 +50 @@
- 	rte_rwlock_write_unlock(&vq->access_lock);
+ 	rte_spinlock_unlock(&vq->access_lock);
@@ -52 +53 @@
-@@ -1607,7 +1616,10 @@ rte_vhost_rx_queue_count(int vid, uint16_t qid)
+@@ -1495,7 +1504,10 @@ rte_vhost_rx_queue_count(int vid, uint16_t qid)
@@ -54 +55 @@
- 	rte_rwlock_write_lock(&vq->access_lock);
+ 	rte_spinlock_lock(&vq->access_lock);
@@ -56 +57 @@
--	if (unlikely(!vq->enabled || vq->avail == NULL))
+-	if (unlikely(vq->enabled == 0 || vq->avail == NULL))