bridge: Clamp forward_delay when enabling STP
[ Upstream commit be4f154d5ef0ca147ab6bcd38857a774133f5450 ]
At some point limits were added to forward_delay. However, the
limits are only enforced when STP is enabled. This created a
scenario where you could have a value outside the allowed range
while STP is disabled, which then stuck around even after STP
is enabled.
This patch fixes this by clamping the value when we enable STP.
I had to move the locking around a bit to ensure that there is
no window where someone could insert a value outside the range
while we're in the middle of enabling STP.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h
index d2c043a..d11a5e1 100644
--- a/net/bridge/br_private.h
+++ b/net/bridge/br_private.h
@@ -714,6 +714,7 @@
extern void br_init_port(struct net_bridge_port *p);
extern void br_become_designated_port(struct net_bridge_port *p);
+extern void __br_set_forward_delay(struct net_bridge *br, unsigned long t);
extern int br_set_forward_delay(struct net_bridge *br, unsigned long x);
extern int br_set_hello_time(struct net_bridge *br, unsigned long x);
extern int br_set_max_age(struct net_bridge *br, unsigned long x);