From: Li Feng <fengli@smartx.com>
To: Maxime Coquelin <maxime.coquelin@redhat.com>,
Chenbo Xia <chenbo.xia@intel.com>
Cc: dev@dpdk.org, Li Feng <fengli@smartx.com>
Subject: [PATCH v3] vhost: avoid potential null pointer access
Date: Tue, 12 Sep 2023 15:42:17 +0800 [thread overview]
Message-ID: <20230912074217.2480397-1-fengli@smartx.com> (raw)
If the user calls rte_vhost_vring_call() on a ring that has been
invalidated, we will encounter SEGV.
We should check the pointer firstly before accessing it.
Signed-off-by: Li Feng <fengli@smartx.com>
---
v2 -> v3:
- Also fix the rte_vhost_vring_call_nonblock.
v1 -> v2:
- Fix rebase error.
lib/vhost/vhost.c | 14 ++++++++------
lib/vhost/vhost.h | 12 ++++++++++--
2 files changed, 18 insertions(+), 8 deletions(-)
diff --git a/lib/vhost/vhost.c b/lib/vhost/vhost.c
index eb6309b681..46f3391167 100644
--- a/lib/vhost/vhost.c
+++ b/lib/vhost/vhost.c
@@ -1327,6 +1327,7 @@ rte_vhost_vring_call(int vid, uint16_t vring_idx)
{
struct virtio_net *dev;
struct vhost_virtqueue *vq;
+ int ret = 0;
dev = get_device(vid);
if (!dev)
@@ -1342,13 +1343,13 @@ rte_vhost_vring_call(int vid, uint16_t vring_idx)
rte_rwlock_read_lock(&vq->access_lock);
if (vq_is_packed(dev))
- vhost_vring_call_packed(dev, vq);
+ ret = vhost_vring_call_packed(dev, vq);
else
- vhost_vring_call_split(dev, vq);
+ ret = vhost_vring_call_split(dev, vq);
rte_rwlock_read_unlock(&vq->access_lock);
- return 0;
+ return ret;
}
int
@@ -1356,6 +1357,7 @@ rte_vhost_vring_call_nonblock(int vid, uint16_t vring_idx)
{
struct virtio_net *dev;
struct vhost_virtqueue *vq;
+ int ret = 0;
dev = get_device(vid);
if (!dev)
@@ -1372,13 +1374,13 @@ rte_vhost_vring_call_nonblock(int vid, uint16_t vring_idx)
return -EAGAIN;
if (vq_is_packed(dev))
- vhost_vring_call_packed(dev, vq);
+ ret = vhost_vring_call_packed(dev, vq);
else
- vhost_vring_call_split(dev, vq);
+ ret = vhost_vring_call_split(dev, vq);
rte_rwlock_read_unlock(&vq->access_lock);
- return 0;
+ return ret;
}
uint16_t
diff --git a/lib/vhost/vhost.h b/lib/vhost/vhost.h
index 9723429b1c..4c09c2ef0e 100644
--- a/lib/vhost/vhost.h
+++ b/lib/vhost/vhost.h
@@ -930,12 +930,15 @@ vhost_vring_inject_irq(struct virtio_net *dev, struct vhost_virtqueue *vq)
dev->notify_ops->guest_notified(dev->vid);
}
-static __rte_always_inline void
+static __rte_always_inline int
vhost_vring_call_split(struct virtio_net *dev, struct vhost_virtqueue *vq)
{
/* Flush used->idx update before we read avail->flags. */
rte_atomic_thread_fence(__ATOMIC_SEQ_CST);
+ if (!vq->avail || !vq->used)
+ return -1;
+
/* Don't kick guest if we don't reach index specified by guest. */
if (dev->features & (1ULL << VIRTIO_RING_F_EVENT_IDX)) {
uint16_t old = vq->signalled_used;
@@ -957,9 +960,10 @@ vhost_vring_call_split(struct virtio_net *dev, struct vhost_virtqueue *vq)
if (!(vq->avail->flags & VRING_AVAIL_F_NO_INTERRUPT))
vhost_vring_inject_irq(dev, vq);
}
+ return 0;
}
-static __rte_always_inline void
+static __rte_always_inline int
vhost_vring_call_packed(struct virtio_net *dev, struct vhost_virtqueue *vq)
{
uint16_t old, new, off, off_wrap;
@@ -968,6 +972,9 @@ vhost_vring_call_packed(struct virtio_net *dev, struct vhost_virtqueue *vq)
/* Flush used desc update. */
rte_atomic_thread_fence(__ATOMIC_SEQ_CST);
+ if (!vq->driver_event)
+ return -1;
+
if (!(dev->features & (1ULL << VIRTIO_RING_F_EVENT_IDX))) {
if (vq->driver_event->flags !=
VRING_EVENT_F_DISABLE)
@@ -1008,6 +1015,7 @@ vhost_vring_call_packed(struct virtio_net *dev, struct vhost_virtqueue *vq)
kick:
if (kick)
vhost_vring_inject_irq(dev, vq);
+ return 0;
}
static __rte_always_inline void
--
2.41.0
next reply other threads:[~2023-09-12 7:42 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-09-12 7:42 Li Feng [this message]
2023-09-25 8:15 ` Maxime Coquelin
2023-09-25 8:26 ` Maxime Coquelin
2023-09-25 10:37 ` Morten Brørup
2023-09-25 10:59 ` Maxime Coquelin
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