diff options
| author | Eric Dumazet <[email protected]> | 2019-06-08 17:22:49 +0000 |
|---|---|---|
| committer | David S. Miller <[email protected]> | 2019-06-16 01:47:31 +0000 |
| commit | 967c05aee439e6e5d7d805e195b3a20ef5c433d6 (patch) | |
| tree | 564caa19735a085c9722d4fb8c184cc23dc7f012 /net/ipv4/tcp_timer.c | |
| parent | tcp: add tcp_min_snd_mss sysctl (diff) | |
| download | kernel-967c05aee439e6e5d7d805e195b3a20ef5c433d6.tar.gz kernel-967c05aee439e6e5d7d805e195b3a20ef5c433d6.zip | |
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 <[email protected]>
Reported-by: Jonathan Lemon <[email protected]>
Cc: Jonathan Looney <[email protected]>
Acked-by: Neal Cardwell <[email protected]>
Cc: Yuchung Cheng <[email protected]>
Cc: Tyler Hicks <[email protected]>
Cc: Bruce Curtis <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
Diffstat (limited to 'net/ipv4/tcp_timer.c')
| -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 5bad937ce779..c801cd37cc2a 100644 --- a/net/ipv4/tcp_timer.c +++ b/net/ipv4/tcp_timer.c @@ -155,6 +155,7 @@ 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); |