From d876a4d2afecacf4b4d8b11479e9f1ed0080bb2e Mon Sep 17 00:00:00 2001 From: Jon Paul Maloy Date: Wed, 23 Nov 2016 23:46:09 -0500 Subject: [PATCH] tipc: improve sanity check for received domain records In commit 35c55c9877f8 ("tipc: add neighbor monitoring framework") we added a data area to the link monitor STATE messages under the assumption that previous versions did not use any such data area. For versions older than Linux 4.3 this assumption is not correct. In those version, all STATE messages sent out from a node inadvertently contain a 16 byte data area containing a string; -a leftover from previous RESET messages which were using this during the setup phase. This string serves no purpose in STATE messages, and should no be there. Unfortunately, this data area is delivered to the link monitor framework, where a sanity check catches that it is not a correct domain record, and drops it. It also issues a rate limited warning about the event. Since such events occur much more frequently than anticipated, we now choose to remove the warning in order to not fill the kernel log with useless contents. We also make the sanity check stricter, to further reduce the risk that such data is inavertently admitted. Signed-off-by: Jon Maloy Signed-off-by: David S. Miller --- net/tipc/monitor.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/net/tipc/monitor.c b/net/tipc/monitor.c index ed97a5876ebe..9e109bb1a207 100644 --- a/net/tipc/monitor.c +++ b/net/tipc/monitor.c @@ -455,14 +455,14 @@ void tipc_mon_rcv(struct net *net, void *data, u16 dlen, u32 addr, int i, applied_bef; state->probing = false; - if (!dlen) - return; /* Sanity check received domain record */ - if ((dlen < new_dlen) || ntohs(arrv_dom->len) != new_dlen) { - pr_warn_ratelimited("Received illegal domain record\n"); + if (dlen < dom_rec_len(arrv_dom, 0)) + return; + if (dlen != dom_rec_len(arrv_dom, new_member_cnt)) + return; + if ((dlen < new_dlen) || ntohs(arrv_dom->len) != new_dlen) return; - } /* Synch generation numbers with peer if link just came up */ if (!state->synched) { -- 2.20.1