4 files changed, 33 insertions, 19 deletions

diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
index 1058aba8d573..b19d60adc606 100644
--- a/drivers/vhost/net.c
+++ b/drivers/vhost/net.c
@@ -1049,7 +1049,7 @@ static int get_rx_bufs(struct vhost_virtqueue *vq,
 	/* len is always initialized before use since we are always called with
 	 * datalen > 0.
 	 */
-	u32 uninitialized_var(len);
+	u32 len;
 
 	while (datalen > 0 && headcount < quota) {
 		if (unlikely(seg >= UIO_MAXIOV)) {
@@ -1106,7 +1106,7 @@ static void handle_rx(struct vhost_net *net)
 {
 	struct vhost_net_virtqueue *nvq = &net->vqs[VHOST_NET_VQ_RX];
 	struct vhost_virtqueue *vq = &nvq->vq;
-	unsigned uninitialized_var(in), log;
+	unsigned in, log;
 	struct vhost_log *vq_log;
 	struct msghdr msg = {
 		.msg_name = NULL,
@@ -1446,13 +1446,9 @@ err:
 	return ERR_PTR(r);
 }
 
-static struct ptr_ring *get_tap_ptr_ring(int fd)
+static struct ptr_ring *get_tap_ptr_ring(struct file *file)
 {
 	struct ptr_ring *ring;
-	struct file *file = fget(fd);
-
-	if (!file)
-		return NULL;
 	ring = tun_get_tx_ring(file);
 	if (!IS_ERR(ring))
 		goto out;
@@ -1461,7 +1457,6 @@ static struct ptr_ring *get_tap_ptr_ring(int fd)
 		goto out;
 	ring = NULL;
 out:
-	fput(file);
 	return ring;
 }
 
@@ -1548,8 +1543,12 @@ static long vhost_net_set_backend(struct vhost_net *n, unsigned index, int fd)
 		r = vhost_net_enable_vq(n, vq);
 		if (r)
 			goto err_used;
-		if (index == VHOST_NET_VQ_RX)
-			nvq->rx_ring = get_tap_ptr_ring(fd);
+		if (index == VHOST_NET_VQ_RX) {
+			if (sock)
+				nvq->rx_ring = get_tap_ptr_ring(sock->file);
+			else
+				nvq->rx_ring = NULL;
+		}
 
 		oldubufs = nvq->ubufs;
 		nvq->ubufs = ubufs;
diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
index 97be299f0a8d..484818796978 100644
--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c
@@ -2050,7 +2050,7 @@ static int translate_desc(struct vhost_virtqueue *vq, u64 addr, u32 len,
 	struct vhost_dev *dev = vq->dev;
 	struct vhost_umem *umem = dev->iotlb ? dev->iotlb : dev->umem;
 	struct iovec *_iov;
-	u64 s = 0;
+	u64 s = 0, last = addr + len - 1;
 	int ret = 0;
 
 	while ((u64)len > s) {
@@ -2061,7 +2061,7 @@ static int translate_desc(struct vhost_virtqueue *vq, u64 addr, u32 len,
 		}
 
 		node = vhost_umem_interval_tree_iter_first(&umem->umem_tree,
-							addr, addr + len - 1);
+							addr, last);
 		if (node == NULL || node->start > addr) {
 			if (umem != dev->iotlb) {
 				ret = -EFAULT;
@@ -2519,9 +2519,19 @@ bool vhost_vq_avail_empty(struct vhost_dev *dev, struct vhost_virtqueue *vq)
 	r = vhost_get_avail_idx(vq, &avail_idx);
 	if (unlikely(r))
 		return false;
+
 	vq->avail_idx = vhost16_to_cpu(vq, avail_idx);
+	if (vq->avail_idx != vq->last_avail_idx) {
+		/* Since we have updated avail_idx, the following
+		 * call to vhost_get_vq_desc() will read available
+		 * ring entries. Make sure that read happens after
+		 * the avail_idx read.
+		 */
+		smp_rmb();
+		return false;
+	}
 
-	return vq->avail_idx == vq->last_avail_idx;
+	return true;
 }
 EXPORT_SYMBOL_GPL(vhost_vq_avail_empty);
 
@@ -2583,12 +2593,11 @@ EXPORT_SYMBOL_GPL(vhost_disable_notify);
 /* Create a new message. */
 struct vhost_msg_node *vhost_new_msg(struct vhost_virtqueue *vq, int type)
 {
-	struct vhost_msg_node *node = kmalloc(sizeof *node, GFP_KERNEL);
+	/* Make sure all padding within the structure is initialized. */
+	struct vhost_msg_node *node = kzalloc(sizeof(*node), GFP_KERNEL);
 	if (!node)
 		return NULL;
 
-	/* Make sure all padding within the structure is initialized. */
-	memset(&node->msg, 0, sizeof node->msg);
 	node->vq = vq;
 	node->msg.type = type;
 	return node;
diff --git a/drivers/vhost/vringh.c b/drivers/vhost/vringh.c
index 4653de001e26..264cbe385a63 100644
--- a/drivers/vhost/vringh.c
+++ b/drivers/vhost/vringh.c
@@ -264,7 +264,7 @@ __vringh_iov(struct vringh *vrh, u16 i,
 	     gfp_t gfp,
 	     int (*copy)(void *dst, const void *src, size_t len))
 {
-	int err, count = 0, up_next, desc_max;
+	int err, count = 0, indirect_count = 0, up_next, desc_max;
 	struct vring_desc desc, *descs;
 	struct vringh_range range = { -1ULL, 0 }, slowrange;
 	bool slow = false;
@@ -321,7 +321,12 @@ __vringh_iov(struct vringh *vrh, u16 i,
 			continue;
 		}
 
-		if (count++ == vrh->vring.num) {
+		if (up_next == -1)
+			count++;
+		else
+			indirect_count++;
+
+		if (count > vrh->vring.num || indirect_count > desc_max) {
 			vringh_bad("Descriptor loop in %p", descs);
 			err = -ELOOP;
 			goto fail;
@@ -383,6 +388,7 @@ __vringh_iov(struct vringh *vrh, u16 i,
 				i = return_from_indirect(vrh, &up_next,
 							 &descs, &desc_max);
 				slow = false;
+				indirect_count = 0;
 			} else
 				break;
 		}
diff --git a/drivers/vhost/vsock.c b/drivers/vhost/vsock.c
index 308df62655dd..64806e562bf6 100644
--- a/drivers/vhost/vsock.c
+++ b/drivers/vhost/vsock.c
@@ -353,7 +353,7 @@ vhost_vsock_alloc_pkt(struct vhost_virtqueue *vq,
 		return NULL;
 	}
 
-	pkt->buf = kmalloc(pkt->len, GFP_KERNEL);
+	pkt->buf = kvmalloc(pkt->len, GFP_KERNEL);
 	if (!pkt->buf) {
 		kfree(pkt);
 		return NULL;