@@ -512,6 +512,7 @@ extern struct net_bridge_port *br_get_port(struct net_bridge *br,
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);
@@ -517,18 +517,27 @@ int br_set_max_age(struct net_bridge *br, unsigned long val)
}
+void __br_set_forward_delay(struct net_bridge *br, unsigned long t)
+{
+ br->bridge_forward_delay = t;
+ if (br_is_root_bridge(br))
+ br->forward_delay = br->bridge_forward_delay;
+}
+
int br_set_forward_delay(struct net_bridge *br, unsigned long val)
{
unsigned long t = clock_t_to_jiffies(val);
+ int err = -ERANGE;
+ spin_lock_bh(&br->lock);
if (br->stp_enabled != BR_NO_STP &&
(t < BR_MIN_FORWARD_DELAY || t > BR_MAX_FORWARD_DELAY))
- return -ERANGE;
+ goto unlock;
- spin_lock_bh(&br->lock);
- br->bridge_forward_delay = t;
- if (br_is_root_bridge(br))
- br->forward_delay = br->bridge_forward_delay;
+ __br_set_forward_delay(br, t);
+ err = 0;
+
+unlock:
spin_unlock_bh(&br->lock);
- return 0;
+ return err;
}
@@ -129,6 +129,14 @@ static void br_stp_start(struct net_bridge *br)
char *envp[] = { NULL };
r = call_usermodehelper(BR_STP_PROG, argv, envp, UMH_WAIT_PROC);
+
+ spin_lock_bh(&br->lock);
+
+ if (br->bridge_forward_delay < BR_MIN_FORWARD_DELAY)
+ __br_set_forward_delay(br, BR_MIN_FORWARD_DELAY);
+ else if (br->bridge_forward_delay < BR_MAX_FORWARD_DELAY)
+ __br_set_forward_delay(br, BR_MAX_FORWARD_DELAY);
+
if (r == 0) {
br->stp_enabled = BR_USER_STP;
br_debug(br, "userspace STP started\n");
@@ -137,10 +145,10 @@ static void br_stp_start(struct net_bridge *br)
br_debug(br, "using kernel STP\n");
/* To start timers on any ports left in blocking */
- spin_lock_bh(&br->lock);
br_port_state_selection(br);
- spin_unlock_bh(&br->lock);
}
+
+ spin_unlock_bh(&br->lock);
}
static void br_stp_stop(struct net_bridge *br)
This is a note to let you know that I have just added a patch titled bridge: Clamp forward_delay when enabling STP to the linux-3.5.y-queue branch of the 3.5.y.z extended stable tree which can be found at: http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.5.y-queue If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 3.5.y.z tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Luis ------ From 5da346ff617272367e706c45a31d43b1e8ea1eeb Mon Sep 17 00:00:00 2001 From: Herbert Xu <herbert@gondor.apana.org.au> Date: Thu, 12 Sep 2013 17:12:05 +1000 Subject: [PATCH] bridge: Clamp forward_delay when enabling STP commit be4f154d5ef0ca147ab6bcd38857a774133f5450 upstream. 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: Luis Henriques <luis.henriques@canonical.com> --- net/bridge/br_private.h | 1 + net/bridge/br_stp.c | 21 +++++++++++++++------ net/bridge/br_stp_if.c | 12 ++++++++++-- 3 files changed, 26 insertions(+), 8 deletions(-) -- 1.8.3.2