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authorCong Wang <xiyou.wangcong@gmail.com>2017-11-07 00:47:22 +0300
committerDavid S. Miller <davem@davemloft.net>2017-11-09 04:03:09 +0300
commited1481681414e4d4264ad46864d5c1da5ff6ccb1 (patch)
tree7674aba4bcb962e836a97dc7a6cced3bf06e37e8 /net/sched
parentaae2c35ec89252639a97769fa72dbbf8f1cc3107 (diff)
downloadlinux-ed1481681414e4d4264ad46864d5c1da5ff6ccb1.tar.xz
cls_cgroup: use tcf_exts_get_net() before call_rcu()
Hold netns refcnt before call_rcu() and release it after the tcf_exts_destroy() is done. Note, on ->destroy() path we have to respect the return value of tcf_exts_get_net(), on other paths it should always return true, so we don't need to care. Cc: Lucas Bates <lucasb@mojatatu.com> Cc: Jamal Hadi Salim <jhs@mojatatu.com> Cc: Jiri Pirko <jiri@resnulli.us> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/sched')
-rw-r--r--net/sched/cls_cgroup.c24
1 files changed, 18 insertions, 6 deletions
diff --git a/net/sched/cls_cgroup.c b/net/sched/cls_cgroup.c
index a97e069bee89..309d5899265f 100644
--- a/net/sched/cls_cgroup.c
+++ b/net/sched/cls_cgroup.c
@@ -60,15 +60,21 @@ static const struct nla_policy cgroup_policy[TCA_CGROUP_MAX + 1] = {
[TCA_CGROUP_EMATCHES] = { .type = NLA_NESTED },
};
+static void __cls_cgroup_destroy(struct cls_cgroup_head *head)
+{
+ tcf_exts_destroy(&head->exts);
+ tcf_em_tree_destroy(&head->ematches);
+ tcf_exts_put_net(&head->exts);
+ kfree(head);
+}
+
static void cls_cgroup_destroy_work(struct work_struct *work)
{
struct cls_cgroup_head *head = container_of(work,
struct cls_cgroup_head,
work);
rtnl_lock();
- tcf_exts_destroy(&head->exts);
- tcf_em_tree_destroy(&head->ematches);
- kfree(head);
+ __cls_cgroup_destroy(head);
rtnl_unlock();
}
@@ -124,8 +130,10 @@ static int cls_cgroup_change(struct net *net, struct sk_buff *in_skb,
goto errout;
rcu_assign_pointer(tp->root, new);
- if (head)
+ if (head) {
+ tcf_exts_get_net(&head->exts);
call_rcu(&head->rcu, cls_cgroup_destroy_rcu);
+ }
return 0;
errout:
tcf_exts_destroy(&new->exts);
@@ -138,8 +146,12 @@ static void cls_cgroup_destroy(struct tcf_proto *tp)
struct cls_cgroup_head *head = rtnl_dereference(tp->root);
/* Head can still be NULL due to cls_cgroup_init(). */
- if (head)
- call_rcu(&head->rcu, cls_cgroup_destroy_rcu);
+ if (head) {
+ if (tcf_exts_get_net(&head->exts))
+ call_rcu(&head->rcu, cls_cgroup_destroy_rcu);
+ else
+ __cls_cgroup_destroy(head);
+ }
}
static int cls_cgroup_delete(struct tcf_proto *tp, void *arg, bool *last)