[PATCH net] net_sched: gact: Fix potential panic in tcf_gact().
From: Hiroaki SHIMODA <hidden>
Date: 2012-08-03 10:57:56
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 <redacted> --- 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