The patch below does not apply to the 4.9-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@xxxxxxxxxxxxxxx>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 82dd0d2a9a76fc8fa2b18d80b987d455728bf83a Mon Sep 17 00:00:00 2001
From: David Ahern <dsahern@xxxxxxxxx>
Date: Thu, 29 Mar 2018 12:49:52 -0700
Subject: [PATCH] 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: 8f58336d3f78a ("net: Add ethernet header for pass through VRF device")
Signed-off-by: Miguel Fadon Perlines <mfadon@xxxxxxxxxx>
Signed-off-by: David Ahern <dsahern@xxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
diff --git a/drivers/net/vrf.c b/drivers/net/vrf.c
index 139c61c8244a..ac40924fe437 100644
--- a/drivers/net/vrf.c
+++ b/drivers/net/vrf.c
@@ -578,12 +578,13 @@ 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);
+ vrf_tx_error(skb->dev, skb);
return ret;
}