Commit 8c76e77f authored by Willem de Bruijn's avatar Willem de Bruijn Committed by David S. Miller
Browse files

tap: call skb_probe_transport_header after setting skb->dev

The BPF flow dissector expects either skb->sk or skb->dev set on
all skbs. Delay flow dissection until after skb->dev is set.

This requires calling from within an rcu read-side critical section.
That is fine, see also the call from tun_xdp_one.

Fixes: d0e13a14

 ("flow_dissector: lookup netns by skb->sk if skb->dev is NULL")
Reported-by: default avatarChristian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: default avatarWillem de Bruijn <willemb@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent aff6db45
......@@ -1177,8 +1177,6 @@ static int tap_get_user_xdp(struct tap_queue *q, struct xdp_buff *xdp)
goto err_kfree;
}
skb_probe_transport_header(skb, ETH_HLEN);
/* Move network header to the right position for VLAN tagged packets */
if ((skb->protocol == htons(ETH_P_8021Q) ||
skb->protocol == htons(ETH_P_8021AD)) &&
......@@ -1189,6 +1187,7 @@ static int tap_get_user_xdp(struct tap_queue *q, struct xdp_buff *xdp)
tap = rcu_dereference(q->tap);
if (tap) {
skb->dev = tap->dev;
skb_probe_transport_header(skb, ETH_HLEN);
dev_queue_xmit(skb);
} else {
kfree_skb(skb);
......
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