Commit a66ce519 authored by Daniel Borkmann's avatar Daniel Borkmann Committed by Greg Kroah-Hartman

vlan: pull on __vlan_insert_tag error path and fix csum correction

[ Upstream commit 9241e2df ]

When __vlan_insert_tag() fails from skb_vlan_push() path due to the
skb_cow_head(), we need to undo the __skb_push() in the error path
as well that was done earlier to move skb->data pointer to mac header.

Moreover, I noticed that when in the non-error path the __skb_pull()
is done and the original offset to mac header was non-zero, we fixup
from a wrong skb->data offset in the checksum complete processing.

So the skb_postpush_rcsum() really needs to be done before __skb_pull()
where skb->data still points to the mac header start and thus operates
under the same conditions as in __vlan_insert_tag().

Fixes: 93515d53 ("net: move vlan pop/push functions into common code")
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Reviewed-by: default avatarJiri Pirko <jiri@mellanox.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 79fdabe8
......@@ -4427,13 +4427,16 @@ int skb_vlan_push(struct sk_buff *skb, __be16 vlan_proto, u16 vlan_tci)
__skb_push(skb, offset);
err = __vlan_insert_tag(skb, skb->vlan_proto,
skb_vlan_tag_get(skb));
if (err)
if (err) {
__skb_pull(skb, offset);
return err;
}
skb->protocol = skb->vlan_proto;
skb->mac_len += VLAN_HLEN;
__skb_pull(skb, offset);
skb_postpush_rcsum(skb, skb->data + (2 * ETH_ALEN), VLAN_HLEN);
__skb_pull(skb, offset);
}
__vlan_hwaccel_put_tag(skb, vlan_proto, vlan_tci);
return 0;
......
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