From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hiroaki SHIMODA Subject: [PATCH net] net_sched: gact: Fix potential panic in tcf_gact(). Date: Fri, 3 Aug 2012 19:57:52 +0900 Message-ID: <20120803195752.32410768d3d806cd241ac7a4@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org To: davem@davemloft.net Return-path: Received: from mail-yx0-f174.google.com ([209.85.213.174]:51261 "EHLO mail-yx0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753110Ab2HCK54 (ORCPT ); Fri, 3 Aug 2012 06:57:56 -0400 Received: by yenl2 with SMTP id l2so653502yen.19 for ; Fri, 03 Aug 2012 03:57:55 -0700 (PDT) Sender: netdev-owner@vger.kernel.org List-ID: 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 --- net/sched/act_gact.c | 14 +++++++++++--- 1 files changed, 11 insertions(+), 3 deletions(-) diff --git a/net/sched/act_gact.c b/net/sched/act_gact.c index f10fb82..05d60859 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; @@ -133,7 +141,7 @@ static int tcf_gact(struct sk_buff *skb, const struct tc_action *a, 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; -- 1.7.8.6