macvtap: always pass ethernet header in linear

[cascardo/linux.git] / drivers / net / macvtap.c

diff --git a/drivers/net/macvtap.c b/drivers/net/macvtap.c
index d636d05..95394ed 100644 (file)
--- a/drivers/net/macvtap.c
+++ b/drivers/net/macvtap.c
@@ -760,6 +760,8 @@ static ssize_t macvtap_get_user(struct macvtap_queue *q, struct msghdr *m,
                        macvtap16_to_cpu(q, vnet_hdr.hdr_len) : GOODCOPY_LEN;
                if (copylen > good_linear)
                        copylen = good_linear;
+               else if (copylen < ETH_HLEN)
+                       copylen = ETH_HLEN;
                linear = copylen;
                i = *from;
                iov_iter_advance(&i, copylen);
@@ -769,10 +771,11 @@ static ssize_t macvtap_get_user(struct macvtap_queue *q, struct msghdr *m,
 
        if (!zerocopy) {
                copylen = len;
-               if (macvtap16_to_cpu(q, vnet_hdr.hdr_len) > good_linear)
+               linear = macvtap16_to_cpu(q, vnet_hdr.hdr_len);
+               if (linear > good_linear)
                        linear = good_linear;
-               else
-                       linear = macvtap16_to_cpu(q, vnet_hdr.hdr_len);
+               else if (linear < ETH_HLEN)
+                       linear = ETH_HLEN;
        }
 
        skb = macvtap_alloc_skb(&q->sk, MACVTAP_RESERVE, copylen,