From: Daniel Borkmann Date: Fri, 9 Aug 2013 14:25:21 +0000 (+0200) Subject: net: sctp: sctp_transport_destroy{, _rcu}: fix potential pointer corruption X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=771085d6bf3c52de29fc213e5bad07a82e57c23e;p=GitHub%2FLineageOS%2Fandroid_kernel_motorola_exynos9610.git net: sctp: sctp_transport_destroy{, _rcu}: fix potential pointer corruption Probably this one is quite unlikely to be triggered, but it's more safe to do the call_rcu() at the end after we have dropped the reference on the asoc and freed sctp packet chunks. The reason why is because in sctp_transport_destroy_rcu() the transport is being kfree()'d, and if we're unlucky enough we could run into corrupted pointers. Probably that's more of theoretical nature, but it's safer to have this simple fix. Introduced by commit 8c98653f ("sctp: sctp_close: fix release of bindings for deferred call_rcu's"). I also did the 8c98653f regression test and it's fine that way. Signed-off-by: Daniel Borkmann Acked-by: Vlad Yasevich Signed-off-by: David S. Miller --- diff --git a/net/sctp/transport.c b/net/sctp/transport.c index bdbbc3fd7c14..8fdd16046d66 100644 --- a/net/sctp/transport.c +++ b/net/sctp/transport.c @@ -181,12 +181,12 @@ static void sctp_transport_destroy(struct sctp_transport *transport) return; } - call_rcu(&transport->rcu, sctp_transport_destroy_rcu); - sctp_packet_free(&transport->packet); if (transport->asoc) sctp_association_put(transport->asoc); + + call_rcu(&transport->rcu, sctp_transport_destroy_rcu); } /* Start T3_rtx timer if it is not already running and update the heartbeat