1 files changed, 15 insertions, 8 deletions

diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
index eec2f11809ff..236553e81027 100644
--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c
@@ -819,7 +819,7 @@ long vhost_vring_ioctl(struct vhost_dev *d, int ioctl, void __user *argp)
 		BUILD_BUG_ON(__alignof__ *vq->used > VRING_USED_ALIGN_SIZE);
 		if ((a.avail_user_addr & (VRING_AVAIL_ALIGN_SIZE - 1)) ||
 		    (a.used_user_addr & (VRING_USED_ALIGN_SIZE - 1)) ||
-		    (a.log_guest_addr & (sizeof(u64) - 1))) {
+		    (a.log_guest_addr & (VRING_USED_ALIGN_SIZE - 1))) {
 			r = -EINVAL;
 			break;
 		}
@@ -1156,6 +1156,8 @@ int vhost_init_used(struct vhost_virtqueue *vq)
 {
 	__virtio16 last_used_idx;
 	int r;
+	bool is_le = vq->is_le;
+
 	if (!vq->private_data) {
 		vq->is_le = virtio_legacy_is_little_endian();
 		return 0;
@@ -1165,15 +1167,20 @@ int vhost_init_used(struct vhost_virtqueue *vq)
 
 	r = vhost_update_used_flags(vq);
 	if (r)
-		return r;
+		goto err;
 	vq->signalled_used_valid = false;
-	if (!access_ok(VERIFY_READ, &vq->used->idx, sizeof vq->used->idx))
-		return -EFAULT;
+	if (!access_ok(VERIFY_READ, &vq->used->idx, sizeof vq->used->idx)) {
+		r = -EFAULT;
+		goto err;
+	}
 	r = __get_user(last_used_idx, &vq->used->idx);
 	if (r)
-		return r;
+		goto err;
 	vq->last_used_idx = vhost16_to_cpu(vq, last_used_idx);
 	return 0;
+err:
+	vq->is_le = is_le;
+	return r;
 }
 EXPORT_SYMBOL_GPL(vhost_init_used);
 
@@ -1369,7 +1376,7 @@ int vhost_get_vq_desc(struct vhost_virtqueue *vq,
 	/* Grab the next descriptor number they're advertising, and increment
 	 * the index we've seen. */
 	if (unlikely(__get_user(ring_head,
-				&vq->avail->ring[last_avail_idx % vq->num]))) {
+				&vq->avail->ring[last_avail_idx & (vq->num - 1)]))) {
 		vq_err(vq, "Failed to read head: idx %d address %p\n",
 		       last_avail_idx,
 		       &vq->avail->ring[last_avail_idx % vq->num]);
@@ -1489,7 +1496,7 @@ static int __vhost_add_used_n(struct vhost_virtqueue *vq,
 	u16 old, new;
 	int start;
 
-	start = vq->last_used_idx % vq->num;
+	start = vq->last_used_idx & (vq->num - 1);
 	used = vq->used->ring + start;
 	if (count == 1) {
 		if (__put_user(heads[0].id, &used->id)) {
@@ -1531,7 +1538,7 @@ int vhost_add_used_n(struct vhost_virtqueue *vq, struct vring_used_elem *heads,
 {
 	int start, n, r;
 
-	start = vq->last_used_idx % vq->num;
+	start = vq->last_used_idx & (vq->num - 1);
 	n = vq->num - start;
 	if (n < count) {
 		r = __vhost_add_used_n(vq, heads, n);