This is a note to let you know that I've just added the patch titled

ipv4: ipv4_default_advmss() should use route mtu

to the 4.14-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...

The filename of the patch is: ipv4-ipv4_default_advmss-should-use-route-mtu.patch and it can be found in the queue-4.14 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.

From foo@baz Mon Dec 18 13:28:59 CET 2017

From: Eric Dumazet edumazet@google.com Date: Wed, 18 Oct 2017 17:02:03 -0700 Subject: ipv4: ipv4_default_advmss() should use route mtu

From: Eric Dumazet edumazet@google.com

[ Upstream commit 164a5e7ad531e181334a3d3f03d0d5ad20d6faea ]

ipv4_default_advmss() incorrectly uses the device MTU instead of the route provided one. IPv6 has the proper behavior, lets harmonize the two protocols.

Signed-off-by: Eric Dumazet edumazet@google.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin alexander.levin@verizon.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/ipv4/route.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/net/ipv4/route.c +++ b/net/ipv4/route.c @@ -1254,7 +1254,7 @@ static void set_class_tag(struct rtable static unsigned int ipv4_default_advmss(const struct dst_entry *dst) { unsigned int header_size = sizeof(struct tcphdr) + sizeof(struct iphdr); - unsigned int advmss = max_t(unsigned int, dst->dev->mtu - header_size, + unsigned int advmss = max_t(unsigned int, ipv4_mtu(dst) - header_size, ip_rt_min_advmss);

return min(advmss, IPV4_MAX_PMTU - header_size);

Patches currently in stable-queue which might be from edumazet@google.com are

queue-4.14/ipv4-ipv4_default_advmss-should-use-route-mtu.patch