tcp: enforce tcp_min_snd_mss in tcp_mtu_probing()
authorEric Dumazet <edumazet@google.com>
Sat, 8 Jun 2019 17:22:49 +0000 (10:22 -0700)
committerDavid S. Miller <davem@davemloft.net>
Sun, 16 Jun 2019 01:47:31 +0000 (18:47 -0700)
commit967c05aee439e6e5d7d805e195b3a20ef5c433d6
tree564caa19735a085c9722d4fb8c184cc23dc7f012
parent5f3e2bf008c2221478101ee72f5cb4654b9fc363
tcp: enforce tcp_min_snd_mss in tcp_mtu_probing()

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>
net/ipv4/tcp_timer.c