diff options
| author | David S. Miller <davem@davemloft.net> | 2010-11-10 21:35:37 -0800 |
|---|---|---|
| committer | Willy Tarreau <w@1wt.eu> | 2011-04-30 16:53:05 +0200 |
| commit | a0d7e098d148e648f72b2dff5173170b59a41aa0 (patch) | |
| tree | 320ee2702360359194044a594f168f8b56d2e7f9 /net | |
| parent | a3551c1c874fbc3a576ffc88541f686422d18c21 (diff) | |
tcp: Increase TCP_MAXSEG socket option minimum.
commit 7a1abd08d52fdeddb3e9a5a33f2f15cc6a5674d2 upstream.
As noted by Steve Chen, since commit
f5fff5dc8a7a3f395b0525c02ba92c95d42b7390 ("tcp: advertise MSS
requested by user") we can end up with a situation where
tcp_select_initial_window() does a divide by a zero (or
even negative) mss value.
The problem is that sometimes we effectively subtract
TCPOLEN_TSTAMP_ALIGNED and/or TCPOLEN_MD5SIG_ALIGNED from the mss.
Fix this by increasing the minimum from 8 to 64.
Reported-by: Steve Chen <schen@mvista.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Cc: Moritz Muehlenhoff <jmm@debian.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'net')
| -rw-r--r-- | net/ipv4/tcp.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index dc2caaf5e162..87538ed935b3 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -2033,7 +2033,7 @@ static int do_tcp_setsockopt(struct sock *sk, int level, /* Values greater than interface MTU won't take effect. However * at the point when this call is done we typically don't yet * know which interface is going to be used */ - if (val < 8 || val > MAX_TCP_WINDOW) { + if (val < 64 || val > MAX_TCP_WINDOW) { err = -EINVAL; break; } |