diff options
| author | Eric Dumazet <edumazet@google.com> | 2019-06-15 17:47:27 -0700 |
|---|---|---|
| committer | Moyster <oysterized@gmail.com> | 2019-07-18 20:56:35 +0200 |
| commit | 0d833add2ecfdc493169b01b5f168f5068c25c6b (patch) | |
| tree | 938497bdfbd42e35a180265c2c8db3c4fbd2ed5f /net | |
| parent | 0cf7fa57098edfb7e381aca397c75a14ad7e9379 (diff) | |
BACKPORT: 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>
[BACKPORT to 3.10: use previous sysctrl method]
Signed-off-by: syphyr@gmail.com
Change-Id: I02c8330a38992461b89081196b1b0ad0add0e6ad
Diffstat (limited to 'net')
| -rw-r--r-- | net/ipv4/tcp_timer.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/net/ipv4/tcp_timer.c b/net/ipv4/tcp_timer.c index 9f4bd1440..8bb66868f 100644 --- a/net/ipv4/tcp_timer.c +++ b/net/ipv4/tcp_timer.c @@ -117,6 +117,7 @@ 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(sysctl_tcp_base_mss, mss); mss = max(mss, 68 - tp->tcp_header_len); + mss = max(mss, sysctl_tcp_min_snd_mss); icsk->icsk_mtup.search_low = tcp_mss_to_mtu(sk, mss); tcp_sync_mss(sk, icsk->icsk_pmtu_cookie); } |