patch 'vhost: fix missing check on virtqueue access' has been queued to stable release 22.11.4

[Xueming Li]

Hi,

FYI, your patch has been queued to stable release 22.11.4

Note it hasn't been pushed to http://dpdk.org/browse/dpdk-stable yet.
It will be pushed if I get no objections before 12/13/23. 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://git.dpdk.org/dpdk-stable/log/?h=22.11-staging

This queued commit can be viewed at:
https://git.dpdk.org/dpdk-stable/commit/?h=22.11-staging&id=2dc5b2aadd3576a168b8a6c8e4e105313022b432

Thanks.

Xueming Li <xuemingl at nvidia.com>

---
>From 2dc5b2aadd3576a168b8a6c8e4e105313022b432 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
Cc: Xueming Li <xuemingl at nvidia.com>

[ 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/vhost/vhost.c | 16 ++++++++++++++--
 1 file changed, 14 insertions(+), 2 deletions(-)

diff --git a/lib/vhost/vhost.c b/lib/vhost/vhost.c
index 69e1a9b049..0188bdb6c5 100644
--- a/lib/vhost/vhost.c
+++ b/lib/vhost/vhost.c
@@ -1382,7 +1382,10 @@ 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;
@@ -1474,9 +1477,15 @@ 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;
@@ -1537,7 +1546,10 @@ rte_vhost_rx_queue_count(int vid, uint16_t qid)
 
 	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_avail_idx;
-- 
2.25.1

---
  Diff of the applied patch vs upstream commit (please double-check if non-empty:
---
--- -	2023-12-11 17:56:23.507470400 +0800
+++ 0008-vhost-fix-missing-check-on-virtqueue-access.patch	2023-12-11 17:56:22.887652300 +0800
@@ -1 +1 @@
-From 094c442cdbf1da3a19ae82ca7069fee8b3a43343 Mon Sep 17 00:00:00 2001
+From 2dc5b2aadd3576a168b8a6c8e4e105313022b432 Mon Sep 17 00:00:00 2001
@@ -4,0 +5,3 @@
+Cc: Xueming Li <xuemingl at nvidia.com>
+
+[ upstream commit 094c442cdbf1da3a19ae82ca7069fee8b3a43343 ]
@@ -12 +14,0 @@
-Cc: stable at dpdk.org
@@ -21 +23 @@
-index b438330063..43173c9eee 100644
+index 69e1a9b049..0188bdb6c5 100644
@@ -24 +26 @@
-@@ -1420,7 +1420,10 @@ rte_vhost_avail_entries(int vid, uint16_t queue_id)
+@@ -1382,7 +1382,10 @@ rte_vhost_avail_entries(int vid, uint16_t queue_id)
@@ -26 +28 @@
- 	rte_rwlock_write_lock(&vq->access_lock);
+ 	rte_spinlock_lock(&vq->access_lock);
@@ -36 +38 @@
-@@ -1512,9 +1515,15 @@ rte_vhost_enable_guest_notification(int vid, uint16_t queue_id, int enable)
+@@ -1474,9 +1477,15 @@ rte_vhost_enable_guest_notification(int vid, uint16_t queue_id, int enable)
@@ -38 +40 @@
- 	rte_rwlock_write_lock(&vq->access_lock);
+ 	rte_spinlock_lock(&vq->access_lock);
@@ -49 +51 @@
- 	rte_rwlock_write_unlock(&vq->access_lock);
+ 	rte_spinlock_unlock(&vq->access_lock);
@@ -52 +54 @@
-@@ -1607,7 +1616,10 @@ rte_vhost_rx_queue_count(int vid, uint16_t qid)
+@@ -1537,7 +1546,10 @@ rte_vhost_rx_queue_count(int vid, uint16_t qid)
@@ -54 +56 @@
- 	rte_rwlock_write_lock(&vq->access_lock);
+ 	rte_spinlock_lock(&vq->access_lock);