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>
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 @@
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 @@
#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 @@
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 @@
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;
