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net sched: fix kernel leak in act_police

PATCH Applied Jeff Mahoney 2 participants 3 messages Aug 31, 2010 – Sep 1, 2010

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Jeff Mahoney

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#0 lore raw

PATCH 1/1 net sched: fix kernel leak in act_police

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 protected]>
Acked-by Jeff Mahoney <[email protected]>
---
 net/sched/act_police.c |   19 ++++++++-----------
 1 file changed, 8 insertions(+), 11 deletions(-)
net/sched/act_police.c +8 -11
@@ -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);
Signature · 2 lines
Jeff Mahoney
SUSE Labs
author
#1 lore raw

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Quoted 5 lines · Jeff Mahoney

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.

Quoted 7 lines

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 protected]>
Acked-by Jeff Mahoney <[email protected]>

Oops. Sorry about the Acked-by. I have a script that I use to rename patches for inclusion in our trees and it tacks that on. This patch was just pulled out of our master branch.

- -Jeff

Quoted 27 lines
---
 net/sched/act_police.c |   19 ++++++++-----------
 1 file changed, 8 insertions(+), 11 deletions(-)
net/sched/act_police.c +8 -7
@@ -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)

net/sched/act_police.c tcf_act_police_dump(struct sk_buff *skb, · line 368

Quoted 10 lines
net/sched/act_police.c +0 -4
 		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
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maintainer Applied
#2 lore raw
In reply to Jeff Mahoney

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

Quoted 5 lines

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.

Quoted 7 lines

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 protected]>
Acked-by Jeff Mahoney <[email protected]>

Applied.