From: Eric Dumazet <edumazet@google.com>
Date: Sat, 8 Jun 2019 17:22:49 +0000 (-0700)
Subject: tcp: enforce tcp_min_snd_mss in tcp_mtu_probing()
X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=4cecd7e369e1b252db1d64451462221b362eed1c;p=pandora-kernel.git

tcp: enforce tcp_min_snd_mss in tcp_mtu_probing()

commit 967c05aee439e6e5d7d805e195b3a20ef5c433d6 upstream.

If mtu probing is enabled tcp_mtu_probing() could very well end up
with a too small MSS.

Use the new sysctl tcp_min_snd_mss to make sure MSS search
is performed in an acceptable range.

CVE-2019-11479 -- tcp mss hardcoded to 48

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Jonathan Lemon <jonathan.lemon@gmail.com>
Cc: Jonathan Looney <jtl@netflix.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Cc: Yuchung Cheng <ycheng@google.com>
Cc: Tyler Hicks <tyhicks@canonical.com>
Cc: Bruce Curtis <brucec@netflix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
[Salvatore Bonaccorso: Backport for context changes in 4.9.168]
[bwh: Backported to 3.16: The sysctl is global]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---

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