4.15-stable review patch. If anyone has any objections, please let me know.
------------------
From: David Ahern <dsahern@xxxxxxxxx>
[ Upstream commit 82dd0d2a9a76fc8fa2b18d80b987d455728bf83a ]
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/net/vrf.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
--- a/drivers/net/vrf.c
+++ b/drivers/net/vrf.c
@@ -578,12 +578,13 @@ static int vrf_finish_output(struct net
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;
}