Home Home > GIT Browse > SLE15
summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorEric Dumazet <edumazet@google.com>2019-06-08 10:22:49 -0700
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2019-06-17 19:51:56 +0200
commit59222807fcc99951dc769cd50e132e319d73d699 (patch)
tree71e8b80e0633e7e60ec99eae543a69825f211e82
parent7f9f8a37e563c67b24ccd57da1d541a95538e8d9 (diff)
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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--net/ipv4/tcp_timer.c1
1 files changed, 1 insertions, 0 deletions
diff --git a/net/ipv4/tcp_timer.c b/net/ipv4/tcp_timer.c
index b1b5a648def6..17335a370e64 100644
--- a/net/ipv4/tcp_timer.c
+++ b/net/ipv4/tcp_timer.c
@@ -166,6 +166,7 @@ static void tcp_mtu_probing(struct inet_connection_sock *icsk, struct sock *sk)
mss = tcp_mtu_to_mss(sk, icsk->icsk_mtup.search_low) >> 1;
mss = min(net->ipv4.sysctl_tcp_base_mss, mss);
mss = max(mss, 68 - tcp_sk(sk)->tcp_header_len);
+ mss = max(mss, net->ipv4.sysctl_tcp_min_snd_mss);
icsk->icsk_mtup.search_low = tcp_mss_to_mtu(sk, mss);
}
tcp_sync_mss(sk, icsk->icsk_pmtu_cookie);