| Message ID | 20180329194952.27097-1-dsahern@gmail.com |
|---|---|
| State | Accepted, archived |
| Delegated to: | David Miller |
| Headers | show |
| Series | [net] vrf: Fix use after free and double free in vrf_finish_output | expand |
From: David Ahern <dsahern@gmail.com> Date: Thu, 29 Mar 2018 12:49:52 -0700 > 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@teldat.com> > Signed-off-by: David Ahern <dsahern@gmail.com> Applied and queued up for -stable, thanks David.
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; }
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@teldat.com> Signed-off-by: David Ahern <dsahern@gmail.com> --- drivers/net/vrf.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)