Commit 82dd0d2a authored Mar 29, 2018 by David Ahern Committed by David S. Miller Mar 30, 2018

vrf: Fix use after free and double free in vrf_finish_output



Miguel reported an skb use after free / double free in vrf_finish_output
when neigh_output returns an error. The vrf driver should return after
the call to neigh_output as it takes over the skb on error path as well.

Patch is a simplified version of Miguel's patch which was written for 4.9,
and updated to top of tree.

Fixes: 8f58336d ("net: Add ethernet header for pass through VRF device")
Signed-off-by: Miguel Fadon Perlines <mfadon@teldat.com>
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent 5807b22c

drivers/net/vrf.c

+3 −2

Original line number	Diff line number	Diff line
		@@ -578,11 +578,12 @@ static int vrf_finish_output(struct net net, struct sock sk, struct sk_buff *s
		if (!IS_ERR(neigh)) {
		sock_confirm_neigh(skb, neigh);
		ret = neigh_output(neigh, skb);
		rcu_read_unlock_bh();
		return ret;
		}

		rcu_read_unlock_bh();
		err:
		if (unlikely(ret < 0))
		vrf_tx_error(skb->dev, skb);
		return ret;
		}

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