[PATCHv2 net 1/4] bonding: fix send_peer_notif overflow

[Hangbin Liu <liuhangbin@gmail.com>]

Bonding send_peer_notif was defined as u8. Since commit 07a4ddec3ce9
("bonding: add an option to specify a delay between peer notifications").
the bond->send_peer_notif will be num_peer_notif multiplied by
peer_notif_delay, which is u8 * u32. This would cause the send_peer_notif
overflow easily. e.g.

  ip link add bond0 type bond mode 1 miimon 100 num_grat_arp 30 peer_notify_delay 1000

To fix the overflow, let's set the send_peer_notif to u32 and limit
peer_notif_delay to 300s.

Fixes: 07a4ddec3ce9 ("bonding: add an option to specify a delay between peer notifications")
Reported-by: Liang Li <liali@redhat.com>
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
---
v2: define send_peer_notif as u32 and limit the peer_notif_delay to 300s
---
 drivers/net/bonding/bond_netlink.c | 6 ++++++
 drivers/net/bonding/bond_options.c | 8 +++++++-
 include/net/bonding.h              | 2 +-
 3 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/drivers/net/bonding/bond_netlink.c b/drivers/net/bonding/bond_netlink.c
index c2d080fc4fc4..09a501cdea0c 100644
--- a/drivers/net/bonding/bond_netlink.c
+++ b/drivers/net/bonding/bond_netlink.c
@@ -244,6 +244,12 @@ static int bond_changelink(struct net_device *bond_dev, struct nlattr *tb[],
 	if (data[IFLA_BOND_PEER_NOTIF_DELAY]) {
 		int delay = nla_get_u32(data[IFLA_BOND_PEER_NOTIF_DELAY]);
 
+		if (delay > 300000) {
+			NL_SET_ERR_MSG_ATTR(extack, data[IFLA_BOND_PEER_NOTIF_DELAY],
+					    "peer_notif_delay should be less than 300s");
+			return -EINVAL;
+		}
+
 		bond_opt_initval(&newval, delay);
 		err = __bond_opt_set(bond, BOND_OPT_PEER_NOTIF_DELAY, &newval,
 				     data[IFLA_BOND_PEER_NOTIF_DELAY], extack);
diff --git a/drivers/net/bonding/bond_options.c b/drivers/net/bonding/bond_options.c
index f71d5517f829..5310cb488f11 100644
--- a/drivers/net/bonding/bond_options.c
+++ b/drivers/net/bonding/bond_options.c
@@ -169,6 +169,12 @@ static const struct bond_opt_value bond_num_peer_notif_tbl[] = {
 	{ NULL,      -1,  0}
 };
 
+static const struct bond_opt_value bond_peer_notif_delay_tbl[] = {
+	{ "off",     0,   0},
+	{ "maxval",  300000, BOND_VALFLAG_MAX},
+	{ NULL,      -1,  0}
+};
+
 static const struct bond_opt_value bond_primary_reselect_tbl[] = {
 	{ "always",  BOND_PRI_RESELECT_ALWAYS,  BOND_VALFLAG_DEFAULT},
 	{ "better",  BOND_PRI_RESELECT_BETTER,  0},
@@ -488,7 +494,7 @@ static const struct bond_option bond_opts[BOND_OPT_LAST] = {
 		.id = BOND_OPT_PEER_NOTIF_DELAY,
 		.name = "peer_notif_delay",
 		.desc = "Delay between each peer notification on failover event, in milliseconds",
-		.values = bond_intmax_tbl,
+		.values = bond_peer_notif_delay_tbl,
 		.set = bond_option_peer_notif_delay_set
 	}
 };
diff --git a/include/net/bonding.h b/include/net/bonding.h
index c3843239517d..2d034e07b796 100644
--- a/include/net/bonding.h
+++ b/include/net/bonding.h
@@ -233,7 +233,7 @@ struct bonding {
 	 */
 	spinlock_t mode_lock;
 	spinlock_t stats_lock;
-	u8	 send_peer_notif;
+	u32	 send_peer_notif;
 	u8       igmp_retrans;
 #ifdef CONFIG_PROC_FS
 	struct   proc_dir_entry *proc_entry;
-- 
2.38.1