Patchwork net sched: fix some kernel memory leaks

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Submitter Eric Dumazet
Date Aug. 17, 2010, 6:04 a.m.
Message ID <1282025062.2487.696.camel@edumazet-laptop>
Download mbox | patch
Permalink /patch/61857/
State Accepted
Delegated to: David Miller
Headers show

Comments

Eric Dumazet - Aug. 17, 2010, 6:04 a.m.
We leak at least 32bits of kernel memory to user land in tc dump,
because we dont init all fields (capab ?) of the dumped structure.

Use C99 initializers so that holes and non explicit fields are zeroed.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
---
 net/sched/act_gact.c    |   21 ++++++++++++---------
 net/sched/act_mirred.c  |   15 ++++++++-------
 net/sched/act_nat.c     |   22 +++++++++++-----------
 net/sched/act_simple.c  |   11 ++++++-----
 net/sched/act_skbedit.c |   11 ++++++-----
 5 files changed, 43 insertions(+), 37 deletions(-)



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David Miller - Aug. 17, 2010, 10:14 p.m.
From: Eric Dumazet <eric.dumazet@gmail.com>
Date: Tue, 17 Aug 2010 08:04:22 +0200

> We leak at least 32bits of kernel memory to user land in tc dump,
> because we dont init all fields (capab ?) of the dumped structure.
> 
> Use C99 initializers so that holes and non explicit fields are zeroed.
> 
> Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>

Applied, thanks for fixing this Eric.
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Patch

diff --git a/net/sched/act_gact.c b/net/sched/act_gact.c
index 8406c66..c2ed90a 100644
--- a/net/sched/act_gact.c
+++ b/net/sched/act_gact.c
@@ -152,21 +152,24 @@  static int tcf_gact(struct sk_buff *skb, struct tc_action *a, struct tcf_result
 static int tcf_gact_dump(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
 {
 	unsigned char *b = skb_tail_pointer(skb);
-	struct tc_gact opt;
 	struct tcf_gact *gact = a->priv;
+	struct tc_gact opt = {
+		.index   = gact->tcf_index,
+		.refcnt  = gact->tcf_refcnt - ref,
+		.bindcnt = gact->tcf_bindcnt - bind,
+		.action  = gact->tcf_action,
+	};
 	struct tcf_t t;
 
-	opt.index = gact->tcf_index;
-	opt.refcnt = gact->tcf_refcnt - ref;
-	opt.bindcnt = gact->tcf_bindcnt - bind;
-	opt.action = gact->tcf_action;
 	NLA_PUT(skb, TCA_GACT_PARMS, sizeof(opt), &opt);
 #ifdef CONFIG_GACT_PROB
 	if (gact->tcfg_ptype) {
-		struct tc_gact_p p_opt;
-		p_opt.paction = gact->tcfg_paction;
-		p_opt.pval = gact->tcfg_pval;
-		p_opt.ptype = gact->tcfg_ptype;
+		struct tc_gact_p p_opt = {
+			.paction = gact->tcfg_paction,
+			.pval    = gact->tcfg_pval,
+			.ptype   = gact->tcfg_ptype,
+		};
+
 		NLA_PUT(skb, TCA_GACT_PROB, sizeof(p_opt), &p_opt);
 	}
 #endif
diff --git a/net/sched/act_mirred.c b/net/sched/act_mirred.c
index 11f195a..0c311be 100644
--- a/net/sched/act_mirred.c
+++ b/net/sched/act_mirred.c
@@ -219,15 +219,16 @@  static int tcf_mirred_dump(struct sk_buff *skb, struct tc_action *a, int bind, i
 {
 	unsigned char *b = skb_tail_pointer(skb);
 	struct tcf_mirred *m = a->priv;
-	struct tc_mirred opt;
+	struct tc_mirred opt = {
+		.index   = m->tcf_index,
+		.action  = m->tcf_action,
+		.refcnt  = m->tcf_refcnt - ref,
+		.bindcnt = m->tcf_bindcnt - bind,
+		.eaction = m->tcfm_eaction,
+		.ifindex = m->tcfm_ifindex,
+	};
 	struct tcf_t t;
 
-	opt.index = m->tcf_index;
-	opt.action = m->tcf_action;
-	opt.refcnt = m->tcf_refcnt - ref;
-	opt.bindcnt = m->tcf_bindcnt - bind;
-	opt.eaction = m->tcfm_eaction;
-	opt.ifindex = m->tcfm_ifindex;
 	NLA_PUT(skb, TCA_MIRRED_PARMS, sizeof(opt), &opt);
 	t.install = jiffies_to_clock_t(jiffies - m->tcf_tm.install);
 	t.lastuse = jiffies_to_clock_t(jiffies - m->tcf_tm.lastuse);
diff --git a/net/sched/act_nat.c b/net/sched/act_nat.c
index 509a2d5..186eb83 100644
--- a/net/sched/act_nat.c
+++ b/net/sched/act_nat.c
@@ -272,19 +272,19 @@  static int tcf_nat_dump(struct sk_buff *skb, struct tc_action *a,
 {
 	unsigned char *b = skb_tail_pointer(skb);
 	struct tcf_nat *p = a->priv;
-	struct tc_nat opt;
+	struct tc_nat opt = {
+		.old_addr = p->old_addr,
+		.new_addr = p->new_addr,
+		.mask     = p->mask,
+		.flags    = p->flags,
+
+		.index    = p->tcf_index,
+		.action   = p->tcf_action,
+		.refcnt   = p->tcf_refcnt - ref,
+		.bindcnt  = p->tcf_bindcnt - bind,
+	};
 	struct tcf_t t;
 
-	opt.old_addr = p->old_addr;
-	opt.new_addr = p->new_addr;
-	opt.mask = p->mask;
-	opt.flags = p->flags;
-
-	opt.index = p->tcf_index;
-	opt.action = p->tcf_action;
-	opt.refcnt = p->tcf_refcnt - ref;
-	opt.bindcnt = p->tcf_bindcnt - bind;
-
 	NLA_PUT(skb, TCA_NAT_PARMS, sizeof(opt), &opt);
 	t.install = jiffies_to_clock_t(jiffies - p->tcf_tm.install);
 	t.lastuse = jiffies_to_clock_t(jiffies - p->tcf_tm.lastuse);
diff --git a/net/sched/act_simple.c b/net/sched/act_simple.c
index 4a1d640..97e84f3 100644
--- a/net/sched/act_simple.c
+++ b/net/sched/act_simple.c
@@ -164,13 +164,14 @@  static inline int tcf_simp_dump(struct sk_buff *skb, struct tc_action *a,
 {
 	unsigned char *b = skb_tail_pointer(skb);
 	struct tcf_defact *d = a->priv;
-	struct tc_defact opt;
+	struct tc_defact opt = {
+		.index   = d->tcf_index,
+		.refcnt  = d->tcf_refcnt - ref,
+		.bindcnt = d->tcf_bindcnt - bind,
+		.action  = d->tcf_action,
+	};
 	struct tcf_t t;
 
-	opt.index = d->tcf_index;
-	opt.refcnt = d->tcf_refcnt - ref;
-	opt.bindcnt = d->tcf_bindcnt - bind;
-	opt.action = d->tcf_action;
 	NLA_PUT(skb, TCA_DEF_PARMS, sizeof(opt), &opt);
 	NLA_PUT_STRING(skb, TCA_DEF_DATA, d->tcfd_defdata);
 	t.install = jiffies_to_clock_t(jiffies - d->tcf_tm.install);
diff --git a/net/sched/act_skbedit.c b/net/sched/act_skbedit.c
index e9607fe..66cbf4e 100644
--- a/net/sched/act_skbedit.c
+++ b/net/sched/act_skbedit.c
@@ -159,13 +159,14 @@  static inline int tcf_skbedit_dump(struct sk_buff *skb, struct tc_action *a,
 {
 	unsigned char *b = skb_tail_pointer(skb);
 	struct tcf_skbedit *d = a->priv;
-	struct tc_skbedit opt;
+	struct tc_skbedit opt = {
+		.index   = d->tcf_index,
+		.refcnt  = d->tcf_refcnt - ref,
+		.bindcnt = d->tcf_bindcnt - bind,
+		.action  = d->tcf_action,
+	};
 	struct tcf_t t;
 
-	opt.index = d->tcf_index;
-	opt.refcnt = d->tcf_refcnt - ref;
-	opt.bindcnt = d->tcf_bindcnt - bind;
-	opt.action = d->tcf_action;
 	NLA_PUT(skb, TCA_SKBEDIT_PARMS, sizeof(opt), &opt);
 	if (d->flags & SKBEDIT_F_PRIORITY)
 		NLA_PUT(skb, TCA_SKBEDIT_PRIORITY, sizeof(d->priority),