vhost_vdpa: Return -EFAULT if copy_from_user() fails (7922460e) · Commits · 戴 / test

The copy_to/from_user() functions return the number of bytes which we weren't able to copy but the ioctl should return -EFAULT if they fail. Fixes: ("vhost-vdpa: fix backend feature ioctls") Signed-off-by:

Dan Carpenter <dan.carpenter@oracle.com> Link: https://lore.kernel.org/r/20201023120853.GI282278@mwanda Signed-off-by:

Michael S. Tsirkin <mst@redhat.com> Cc: stable@vger.kernel.org Acked-by:

Jason Wang <jasowang@redhat.com>

drivers/vhost/vdpa.c

+5 −5

Original line number	Diff line number	Diff line
		@@ -432,12 +432,11 @@ static long vhost_vdpa_unlocked_ioctl(struct file *filep,
		void __user argp = (void __user )arg;
		u64 __user *featurep = argp;
		u64 features;
		long r;
		long r = 0;

		if (cmd == VHOST_SET_BACKEND_FEATURES) {
		r = copy_from_user(&features, featurep, sizeof(features));
		if (r)
		return r;
		if (copy_from_user(&features, featurep, sizeof(features)))
		return -EFAULT;
		if (features & ~VHOST_VDPA_BACKEND_FEATURES)
		return -EOPNOTSUPP;
		vhost_set_backend_features(&v->vdev, features);
		@@ -480,7 +479,8 @@ static long vhost_vdpa_unlocked_ioctl(struct file *filep,
		break;
		case VHOST_GET_BACKEND_FEATURES:
		features = VHOST_VDPA_BACKEND_FEATURES;
		r = copy_to_user(featurep, &features, sizeof(features));
		if (copy_to_user(featurep, &features, sizeof(features)))
		r = -EFAULT;
		break;
		case VHOST_VDPA_GET_IOVA_RANGE:
		r = vhost_vdpa_get_iova_range(v, argp);

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