From mboxrd@z Thu Jan  1 00:00:00 1970
From: Timo Teras <timo.teras@iki.fi>
Subject: request for -stable: "route: Use ipv4_mtu instead of raw rt_pmtu"
Date: Mon, 13 Jul 2015 20:26:54 +0300
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Cc: Herbert Xu <herbert@gondor.apana.org.au>,
	Li Wei <lw@cn.fujitsu.com>, netdev@vger.kernel.org
To: "David S. Miller" <davem@davemloft.net>
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Hi,

Can you queue for active older -stables up to 3.18:

commit 3cdaa5be9e81 "ipv4: Don't increase PMTU with Datagram Too Big message"
commit cb6ccf09d6b9 "route: Use ipv4_mtu instead of raw rt_pmtu"

commit 3cdaa5be9e81 made it to 3.19.y and was later fixed additionally
with conversion to ipv4_mtu() in the second referenced commit.

However, these patches together will fix another case that is not so
obvious: the case if the original route had MTU set on it. Previously
it was ignored but using ipv4_mtu as the first check will also check
RTAX_MTU on metrics. This fixes the nasty issue that PMTU can trigger
to send larger packets then what was explicitly configured via a static
route mtu.

Thanks,
Timo