linux-kernel - [ 151/184] net_sched: gact: Fix potential panic in tcf

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20130604172136.560055883@1wt.eu>
Date:	Tue, 04 Jun 2013 19:24:01 +0200
From:	Willy Tarreau <w@....eu>
To:	linux-kernel@...r.kernel.org, stable@...r.kernel.org
Cc:	Hiroaki SHIMODA <shimoda.hiroaki@...il.com>,
	"David S. Miller" <davem@...emloft.net>,
	Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	Willy Tarreau <w@....eu>
Subject: [ 151/184] net_sched: gact: Fix potential panic in tcf_gact().

2.6.32-longterm review patch.  If anyone has any objections, please let me know.

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

From: Hiroaki SHIMODA <shimoda.hiroaki@...il.com>

[ Upstream commit 696ecdc10622d86541f2e35cc16e15b6b3b1b67e ]

gact_rand array is accessed by gact->tcfg_ptype whose value
is assumed to less than MAX_RAND, but any range checks are
not performed.

So add a check in tcf_gact_init(). And in tcf_gact(), we can
reduce a branch.

Signed-off-by: Hiroaki SHIMODA <shimoda.hiroaki@...il.com>
Signed-off-by: David S. Miller <davem@...emloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Signed-off-by: Willy Tarreau <w@....eu>
---
 net/sched/act_gact.c | 14 +++++++++++---
 1 file changed, 11 insertions(+), 3 deletions(-)

diff --git a/net/sched/act_gact.c b/net/sched/act_gact.c
index f9fc6ec..faebd8a 100644
--- a/net/sched/act_gact.c
+++ b/net/sched/act_gact.c
@@ -67,6 +67,9 @@ static int tcf_gact_init(struct nlattr *nla, struct nlattr *est,
 	struct tcf_common *pc;
 	int ret = 0;
 	int err;
+#ifdef CONFIG_GACT_PROB
+	struct tc_gact_p *p_parm = NULL;
+#endif
 
 	if (nla == NULL)
 		return -EINVAL;
@@ -82,6 +85,12 @@ static int tcf_gact_init(struct nlattr *nla, struct nlattr *est,
 #ifndef CONFIG_GACT_PROB
 	if (tb[TCA_GACT_PROB] != NULL)
 		return -EOPNOTSUPP;
+#else
+	if (tb[TCA_GACT_PROB]) {
+		p_parm = nla_data(tb[TCA_GACT_PROB]);
+		if (p_parm->ptype >= MAX_RAND)
+			return -EINVAL;
+	}
 #endif
 
 	pc = tcf_hash_check(parm->index, a, bind, &gact_hash_info);
@@ -103,8 +112,7 @@ static int tcf_gact_init(struct nlattr *nla, struct nlattr *est,
 	spin_lock_bh(&gact->tcf_lock);
 	gact->tcf_action = parm->action;
 #ifdef CONFIG_GACT_PROB
-	if (tb[TCA_GACT_PROB] != NULL) {
-		struct tc_gact_p *p_parm = nla_data(tb[TCA_GACT_PROB]);
+	if (p_parm) {
 		gact->tcfg_paction = p_parm->paction;
 		gact->tcfg_pval    = p_parm->pval;
 		gact->tcfg_ptype   = p_parm->ptype;
@@ -132,7 +140,7 @@ static int tcf_gact(struct sk_buff *skb, struct tc_action *a, struct tcf_result
 
 	spin_lock(&gact->tcf_lock);
 #ifdef CONFIG_GACT_PROB
-	if (gact->tcfg_ptype && gact_rand[gact->tcfg_ptype] != NULL)
+	if (gact->tcfg_ptype)
 		action = gact_rand[gact->tcfg_ptype](gact);
 	else
 		action = gact->tcf_action;
-- 
1.7.12.2.21.g234cd45.dirty



--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/