4.15-stable review patch. If anyone has any objections, please let me know.
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From: David Ahern dsahern@gmail.com
[ 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@teldat.com Signed-off-by: David Ahern dsahern@gmail.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- 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; }