netdev - [PATCH net 1/1] net: tcp: Permit user set TCP

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Date:   Tue, 21 Mar 2017 05:30:17 +0800
From:   fgao@...ai8.com
To:     davem@...emloft.net, kuznet@....inr.ac.ru, jmorris@...ei.org,
        netdev@...r.kernel.org, gfree.wind@...il.com
Cc:     Gao Feng <fgao@...ai8.com>
Subject: [PATCH net 1/1] net: tcp: Permit user set TCP_MAXSEG to default value

From: Gao Feng <fgao@...ai8.com>

When user_mss is zero, it means use the default value. But the current
codes don't permit user set TCP_MAXSEG to the default value.
It would return the -EINVAL when val is zero.

Signed-off-by: Gao Feng <fgao@...ai8.com>
---
 net/ipv4/tcp.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 1e319a5..dd5e8e2 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -2470,7 +2470,8 @@ 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 < TCP_MIN_MSS || val > MAX_TCP_WINDOW) {
+		if (val < 0 || (val > 0 && val < TCP_MIN_MSS) ||
+		    val > MAX_TCP_WINDOW) {
 			err = -EINVAL;
 			break;
 		}
-- 
1.9.1