Subject: [PATCH] net sched: fix kernel leak in act_police

From: Jeff Mahoney <[email-masked]>
Date: Tue, 31 Aug 2010 19:21:42 -0400

While reviewing commit 1c40be12f7d8ca1d387510d39787b12e512a7ce8, I
 audited other users of tc_action_ops->dump for information leaks.

 That commit covered almost all of them but act_police still had a leak.

 opt.limit and opt.capab aren't zeroed out before the structure is
 passed out.

 This patch uses the C99 initializers to zero everything unused out.

Signed-off-by: Jeff Mahoney <[email-masked]>
Acked-by: Jeff Mahoney <[email-masked]>
---
 net/sched/act_police.c |   19 ++++++++-----------
 1 file changed, 8 insertions(+), 11 deletions(-)

--- a/net/sched/act_police.c
+++ b/net/sched/act_police.c
@@ -350,22 +350,19 @@ tcf_act_police_dump(struct sk_buff *skb,
 {
 	unsigned char *b = skb_tail_pointer(skb);
 	struct tcf_police *police = a->priv;
-	struct tc_police opt;
+	struct tc_police opt = {
+		.index = police->tcf_index,
+		.action = police->tcf_action,
+		.mtu = police->tcfp_mtu,
+		.burst = police->tcfp_burst,
+		.refcnt = police->tcf_refcnt - ref,
+		.bindcnt = police->tcf_bindcnt - bind,
+	};
 
-	opt.index = police->tcf_index;
-	opt.action = police->tcf_action;
-	opt.mtu = police->tcfp_mtu;
-	opt.burst = police->tcfp_burst;
-	opt.refcnt = police->tcf_refcnt - ref;
-	opt.bindcnt = police->tcf_bindcnt - bind;
 	if (police->tcfp_R_tab)
 		opt.rate = police->tcfp_R_tab->rate;
-	else
-		memset(&opt.rate, 0, sizeof(opt.rate));
 	if (police->tcfp_P_tab)
 		opt.peakrate = police->tcfp_P_tab->rate;
-	else
-		memset(&opt.peakrate, 0, sizeof(opt.peakrate));
 	NLA_PUT(skb, TCA_POLICE_TBF, sizeof(opt), &opt);
 	if (police->tcfp_result)
 		NLA_PUT_U32(skb, TCA_POLICE_RESULT, police->tcfp_result);
-- 
Jeff Mahoney
SUSE Labs