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authorDavid S. Miller <davem@davemloft.net>2010-11-11 08:35:37 +0300
committerDavid S. Miller <davem@davemloft.net>2010-11-11 08:35:37 +0300
commit7a1abd08d52fdeddb3e9a5a33f2f15cc6a5674d2 (patch)
treef566af2a622e5416056c70633576a1a46b8bf6aa /net/ipv4/tcp.c
parent8d987e5c75107ca7515fa19e857cfa24aab6ec8f (diff)
downloadlinux-7a1abd08d52fdeddb3e9a5a33f2f15cc6a5674d2.tar.xz
tcp: Increase TCP_MAXSEG socket option minimum.
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>
Diffstat (limited to 'net/ipv4/tcp.c')
-rw-r--r--net/ipv4/tcp.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 245603c4ad48..081419969485 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -2246,7 +2246,7 @@ 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;
}