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authorCong Wang <xiyou.wangcong@gmail.com>2018-08-19 22:22:05 +0300
committerDavid S. Miller <davem@davemloft.net>2018-08-21 22:45:44 +0300
commitedfaf94fa705181eeb2fe0c36c0b902dedbd40f1 (patch)
tree72127013952f5bc69ceb15132b8d67060db120da /net
parentb93c1b5ac8643cc08bb74fa8ae21d6c63dfcb23d (diff)
downloadlinux-edfaf94fa705181eeb2fe0c36c0b902dedbd40f1.tar.xz
net_sched: improve and refactor tcf_action_put_many()
tcf_action_put_many() is mostly called to clean up actions on failure path, but tcf_action_put_many(&actions[acts_deleted]) is used in the ugliest way: it passes a slice of the array and uses an additional NULL at the end to avoid out-of-bound access. acts_deleted is completely unnecessary since we can teach tcf_action_put_many() scan the whole array and checks against NULL pointer. Which also means tcf_action_delete() should set deleted action pointers to NULL to avoid double free. Fixes: 90b73b77d08e ("net: sched: change action API to use array of pointers to actions") Cc: Jiri Pirko <jiri@mellanox.com> Cc: Vlad Buslov <vladbu@mellanox.com> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
-rw-r--r--net/sched/act_api.c31
1 files changed, 15 insertions, 16 deletions
diff --git a/net/sched/act_api.c b/net/sched/act_api.c
index 229d63c99be2..cd69a6afcf88 100644
--- a/net/sched/act_api.c
+++ b/net/sched/act_api.c
@@ -686,14 +686,18 @@ static int tcf_action_put(struct tc_action *p)
return __tcf_action_put(p, false);
}
+/* Put all actions in this array, skip those NULL's. */
static void tcf_action_put_many(struct tc_action *actions[])
{
int i;
- for (i = 0; i < TCA_ACT_MAX_PRIO && actions[i]; i++) {
+ for (i = 0; i < TCA_ACT_MAX_PRIO; i++) {
struct tc_action *a = actions[i];
- const struct tc_action_ops *ops = a->ops;
+ const struct tc_action_ops *ops;
+ if (!a)
+ continue;
+ ops = a->ops;
if (tcf_action_put(a))
module_put(ops->owner);
}
@@ -1176,7 +1180,7 @@ err_out:
}
static int tcf_action_delete(struct net *net, struct tc_action *actions[],
- int *acts_deleted, struct netlink_ext_ack *extack)
+ struct netlink_ext_ack *extack)
{
u32 act_index;
int ret, i;
@@ -1196,20 +1200,17 @@ static int tcf_action_delete(struct net *net, struct tc_action *actions[],
} else {
/* now do the delete */
ret = ops->delete(net, act_index);
- if (ret < 0) {
- *acts_deleted = i + 1;
+ if (ret < 0)
return ret;
- }
}
+ actions[i] = NULL;
}
- *acts_deleted = i;
return 0;
}
static int
tcf_del_notify(struct net *net, struct nlmsghdr *n, struct tc_action *actions[],
- int *acts_deleted, u32 portid, size_t attr_size,
- struct netlink_ext_ack *extack)
+ u32 portid, size_t attr_size, struct netlink_ext_ack *extack)
{
int ret;
struct sk_buff *skb;
@@ -1227,7 +1228,7 @@ tcf_del_notify(struct net *net, struct nlmsghdr *n, struct tc_action *actions[],
}
/* now do the delete */
- ret = tcf_action_delete(net, actions, acts_deleted, extack);
+ ret = tcf_action_delete(net, actions, extack);
if (ret < 0) {
NL_SET_ERR_MSG(extack, "Failed to delete TC action");
kfree_skb(skb);
@@ -1249,8 +1250,7 @@ tca_action_gd(struct net *net, struct nlattr *nla, struct nlmsghdr *n,
struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
struct tc_action *act;
size_t attr_size = 0;
- struct tc_action *actions[TCA_ACT_MAX_PRIO + 1] = {};
- int acts_deleted = 0;
+ struct tc_action *actions[TCA_ACT_MAX_PRIO] = {};
ret = nla_parse_nested(tb, TCA_ACT_MAX_PRIO, nla, NULL, extack);
if (ret < 0)
@@ -1280,14 +1280,13 @@ tca_action_gd(struct net *net, struct nlattr *nla, struct nlmsghdr *n,
if (event == RTM_GETACTION)
ret = tcf_get_notify(net, portid, n, actions, event, extack);
else { /* delete */
- ret = tcf_del_notify(net, n, actions, &acts_deleted, portid,
- attr_size, extack);
+ ret = tcf_del_notify(net, n, actions, portid, attr_size, extack);
if (ret)
goto err;
- return ret;
+ return 0;
}
err:
- tcf_action_put_many(&actions[acts_deleted]);
+ tcf_action_put_many(actions);
return ret;
}