[PATCH net-next] net: ipv6: avoid accepting values greater than 2 for accept_untracked_na

[Jaehee Park]

The accept_untracked_na sysctl changed from a boolean to an integer
when a new knob '2' was added. This patch provides a safeguard to avoid
accepting values that are not defined in the sysctl. When setting a
value greater than 2, the user will get an 'invalid argument' warning.

Signed-off-by: Jaehee Park <jhpark1013@xxxxxxxxx>
Suggested-by: Nicolas Dichtel <nicolas.dichtel@xxxxxxxxx>
Suggested-by: Roopa Prabhu <roopa@xxxxxxxxxx>
---
 net/ipv6/addrconf.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index 6ed807b6c647..d3e77ea24f05 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -7042,9 +7042,9 @@ static const struct ctl_table addrconf_sysctl[] = {
 		.data		= &ipv6_devconf.accept_untracked_na,
 		.maxlen		= sizeof(int),
 		.mode		= 0644,
-		.proc_handler	= proc_dointvec,
+		.proc_handler	= proc_dointvec_minmax,
 		.extra1		= (void *)SYSCTL_ZERO,
-		.extra2		= (void *)SYSCTL_ONE,
+		.extra2		= (void *)SYSCTL_TWO,
 	},
 	{
 		/* sentinel */
-- 
2.30.2