1 files changed, 2 insertions, 1 deletions

diff --git a/drivers/net/macvtap.c b/drivers/net/macvtap.c
index 2300e4599520..6696e56e6320 100644
--- a/drivers/net/macvtap.c
+++ b/drivers/net/macvtap.c
@@ -530,8 +530,9 @@ static ssize_t macvtap_get_user(struct macvtap_queue *q,
                 vnet_hdr_len = q->vnet_hdr_sz;
 
                 err = -EINVAL;
-                if ((len -= vnet_hdr_len) < 0)
+                if (len < vnet_hdr_len)
                         goto err;
+                len -= vnet_hdr_len;
 
                 err = memcpy_fromiovecend((void *)&vnet_hdr, iv, 0,
                                            sizeof(vnet_hdr));