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| author | Herbert Xu <herbert@gondor.apana.org.au> | 2013-09-12 17:12:05 +1000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2013-09-12 23:32:14 -0400 |
| commit | be4f154d5ef0ca147ab6bcd38857a774133f5450 (patch) | |
| tree | a0d1f8c90c823bbecebaf30a02e2b5ad79c97944 /net/bridge/br_stp_if.c | |
| parent | 9a0620133ccce9dd35c00a96405c8d80938c2cc0 (diff) | |
| download | linux-stable-be4f154d5ef0ca147ab6bcd38857a774133f5450.tar.gz linux-stable-be4f154d5ef0ca147ab6bcd38857a774133f5450.tar.bz2 linux-stable-be4f154d5ef0ca147ab6bcd38857a774133f5450.zip | |
bridge: Clamp forward_delay when enabling STP
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>
Cheers,
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/bridge/br_stp_if.c')
| -rw-r--r-- | net/bridge/br_stp_if.c | 12 |
1 files changed, 10 insertions, 2 deletions
diff --git a/net/bridge/br_stp_if.c b/net/bridge/br_stp_if.c index d45e760141bb..108084a04671 100644 --- a/net/bridge/br_stp_if.c +++ b/net/bridge/br_stp_if.c @@ -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) |