[PATCH 41/75] sysctl net: Keep tcp_syn_retries inside the boundary

[Luis Henriques]

3.5.7.19 -stable review patch.  If anyone has any objections, please let me know.

------------------

From: Michal Tesar <mtesar at redhat.com>

commit 651e92716aaae60fc41b9652f54cb6803896e0da upstream.

Limit the min/max value passed to the
/proc/sys/net/ipv4/tcp_syn_retries.

Signed-off-by: Michal Tesar <mtesar at redhat.com>
Signed-off-by: David S. Miller <davem at davemloft.net>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 net/ipv4/sysctl_net_ipv4.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/net/ipv4/sysctl_net_ipv4.c b/net/ipv4/sysctl_net_ipv4.c
index e6791f2..d56c8bb 100644
--- a/net/ipv4/sysctl_net_ipv4.c
+++ b/net/ipv4/sysctl_net_ipv4.c
@@ -35,6 +35,8 @@ static int tcp_adv_win_scale_min = -31;
 static int tcp_adv_win_scale_max = 31;
 static int ip_ttl_min = 1;
 static int ip_ttl_max = 255;
+static int tcp_syn_retries_min = 1;
+static int tcp_syn_retries_max = MAX_TCP_SYNCNT;
 static int ip_ping_group_range_min[] = { 0, 0 };
 static int ip_ping_group_range_max[] = { GID_T_MAX, GID_T_MAX };
 
@@ -277,7 +279,9 @@ static struct ctl_table ipv4_table[] = {
 		.data		= &sysctl_tcp_syn_retries,
 		.maxlen		= sizeof(int),
 		.mode		= 0644,
-		.proc_handler	= proc_dointvec
+		.proc_handler	= proc_dointvec_minmax,
+		.extra1		= &tcp_syn_retries_min,
+		.extra2		= &tcp_syn_retries_max
 	},
 	{
 		.procname	= "tcp_synack_retries",
-- 
1.8.3.2