dlm: fix connection stealing if using SCTP
commit28926a0965a943f7c1586342f9482a6e41b4f0c9
authorMarcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Tue, 11 Aug 2015 22:22:20 +0000 (11 19:22 -0300)
committerDavid Teigland <teigland@redhat.com>
Mon, 17 Aug 2015 21:22:15 +0000 (17 16:22 -0500)
treea8c435d7771edfac196c15d10c16fe322e77ef6d
parentf7644cbfcdf03528f0f450f3940c4985b2291f49
dlm: fix connection stealing if using SCTP

When using SCTP and accepting a new connection, DLM currently validates
if the peer trying to connect to it is one of the cluster nodes, but it
doesn't check if it already has a connection to it or not.

If it already had a connection, it will be overwritten, and the new one
will be used for writes, possibly causing the node to leave the cluster
due to communication breakage.

Still, one could DoS the node by attempting N connections and keeping
them open.

As said, but being explicit, both situations are only triggerable from
other cluster nodes, but are doable with only user-level perms.

Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David Teigland <teigland@redhat.com>
fs/dlm/lowcomms.c