[PATCH 4.19 004/191] net: dsa: tag_qca: Make sure there is headroom for tag

[Greg Kroah-Hartman]

From: Per Forlin <per.forlin@xxxxxxxx>

[ Upstream commit 04fb91243a853dbde216d829c79d9632e52aa8d9 ]

Passing tag size to skb_cow_head will make sure
there is enough headroom for the tag data.
This change does not introduce any overhead in case there
is already available headroom for tag.

Signed-off-by: Per Forlin <perfn@xxxxxxxx>
Reviewed-by: Florian Fainelli <f.fainelli@xxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 net/dsa/tag_qca.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/net/dsa/tag_qca.c
+++ b/net/dsa/tag_qca.c
@@ -41,7 +41,7 @@ static struct sk_buff *qca_tag_xmit(stru
 	struct dsa_port *dp = dsa_slave_to_port(dev);
 	u16 *phdr, hdr;
 
-	if (skb_cow_head(skb, 0) < 0)
+	if (skb_cow_head(skb, QCA_HDR_LEN) < 0)
 		return NULL;
 
 	skb_push(skb, QCA_HDR_LEN);