[PATCH 014/270] netfilter: xt_limit: have r->cost != 0 case work

From: Herton Ronaldo Krzesinski
Date: Mon Nov 26 2012 - 12:00:40 EST


3.5.7u1 -stable review patch. If anyone has any objections, please let me know.

------------------

From: Jan Engelhardt <jengelh@xxxxxxx>

commit 82e6bfe2fbc4d48852114c4f979137cd5bf1d1a8 upstream.

Commit v2.6.19-rc1~1272^2~41 tells us that r->cost != 0 can happen when
a running state is saved to userspace and then reinstated from there.

Make sure that private xt_limit area is initialized with correct values.
Otherwise, random matchings due to use of uninitialized memory.

Signed-off-by: Jan Engelhardt <jengelh@xxxxxxx>
Signed-off-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
Acked-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Herton Ronaldo Krzesinski <herton.krzesinski@xxxxxxxxxxxxx>
---
net/netfilter/xt_limit.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/net/netfilter/xt_limit.c b/net/netfilter/xt_limit.c
index 5c22ce8..a4c1e45 100644
--- a/net/netfilter/xt_limit.c
+++ b/net/netfilter/xt_limit.c
@@ -117,11 +117,11 @@ static int limit_mt_check(const struct xt_mtchk_param *par)

/* For SMP, we only want to use one set of state. */
r->master = priv;
+ /* User avg in seconds * XT_LIMIT_SCALE: convert to jiffies *
+ 128. */
+ priv->prev = jiffies;
+ priv->credit = user2credits(r->avg * r->burst); /* Credits full. */
if (r->cost == 0) {
- /* User avg in seconds * XT_LIMIT_SCALE: convert to jiffies *
- 128. */
- priv->prev = jiffies;
- priv->credit = user2credits(r->avg * r->burst); /* Credits full. */
r->credit_cap = priv->credit; /* Credits full. */
r->cost = user2credits(r->avg);
}
--
1.7.9.5

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