drivers/net/macvtap: fix error check

'len' is unsigned of type size_t and can't be negative.

Signed-off-by: Nicolas Kaiser <nikai@nikai.net>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/macvtap.c b/drivers/net/macvtap.c
index 5933621ac3ffa73f7c3a19db049b5bbc813560be..fc27a9926d9e52c28a63d6be8852518e5cebb4da 100644 (file)
--- a/drivers/net/macvtap.c
+++ b/drivers/net/macvtap.c
@@ -528,8 +528,9 @@ 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));