net_sched: gact: Fix potential panic in tcf_gact().

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@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Hiroaki SHIMODA 2012-08-03 19:57:52 +09:00 committed by David S. Miller
parent f3f9f332e2
commit 696ecdc106

View File

@ -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;