vfio/pci: Fix potential memory leak in vfio_msi_cap_len

[ Upstream commit 30ea32ab1951c80c6113f300fce2c70cd12659e4 ]

Free allocated vdev->msi_perm in error path.
Signed-off-by: NLi Qiang <liq3ea@gmail.com>
Reviewed-by: NEric Auger <eric.auger@redhat.com>
Signed-off-by: NAlex Williamson <alex.williamson@redhat.com>
Signed-off-by: NSasha Levin <sashal@kernel.org>

drivers/vfio/pci/vfio_pci_config.c

@@ -1180,8 +1180,10 @@ static int vfio_msi_cap_len(struct vfio_pci_device *vdev, u8 pos)
 		return -ENOMEM;
 
 	ret = init_pci_cap_msi_perm(vdev->msi_perm, len, flags);
-	if (ret)
+	if (ret) {
+		kfree(vdev->msi_perm);
 		return ret;
+	}
 
 	return len;
 }