net: bridge: fix multicast-to-unicast with fraglist GSO

[ Upstream commit 59c878cbcdd80ed39315573b3511d0acfd3501b5 ]

Calling skb_copy on a SKB_GSO_FRAGLIST skb is not valid, since it returns
an invalid linearized skb. This code only needs to change the ethernet
header, so pskb_copy is the right function to call here.

Fixes: 6db6f0eae605 ("bridge: multicast to unicast")
Signed-off-by: Felix Fietkau <nbd@nbd.name>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Acked-by: Nikolay Aleksandrov <razor@blackwall.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
(cherry picked from commit 01386957ca757e31fb66caceb303f71f9e577b83)
Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com>
diff --git a/net/bridge/br_forward.c b/net/bridge/br_forward.c
index 57f69f3..1f0e2c6 100644
--- a/net/bridge/br_forward.c
+++ b/net/bridge/br_forward.c
@@ -243,7 +243,7 @@
 	if (skb->dev == p->dev && ether_addr_equal(src, addr))
 		return;
 
-	skb = skb_copy(skb, GFP_ATOMIC);
+	skb = pskb_copy(skb, GFP_ATOMIC);
 	if (!skb) {
 		dev->stats.tx_dropped++;
 		return;