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authorMinoru Usui <usui@mxm.nes.nec.co.jp>2009-06-02 02:17:34 -0700
committerDavid S. Miller <davem@davemloft.net>2009-06-02 02:17:34 -0700
commit12186be7d2e1106cede1cc728526e3d7998cbe94 (patch)
treea27e9c1cf720fbd31d67c27ea1426a0ae891733b
parentea30e11970a96cfe5e32c03a29332554573b4a10 (diff)
net_cls: fix unconfigured struct tcf_proto keeps chaining and avoid kernel panic when we use cls_cgroup
This patch fixes a bug which unconfigured struct tcf_proto keeps chaining in tc_ctl_tfilter(), and avoids kernel panic in cls_cgroup_classify() when we use cls_cgroup. When we execute 'tc filter add', tcf_proto is allocated, initialized by classifier's init(), and chained. After it's chained, tc_ctl_tfilter() calls classifier's change(). When classifier's change() fails, tc_ctl_tfilter() does not free and keeps tcf_proto. In addition, cls_cgroup is initialized in change() not in init(). It accesses unconfigured struct tcf_proto which is chained before change(), then hits Oops. Signed-off-by: Minoru Usui <usui@mxm.nes.nec.co.jp> Signed-off-by: Jarek Poplawski <jarkao2@gmail.com> Signed-off-by: Jamal Hadi Salim <hadi@cyberus.ca> Tested-by: Minoru Usui <usui@mxm.nes.nec.co.jp> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--net/sched/cls_api.c23
1 files changed, 17 insertions, 6 deletions
diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c
index 0759f32e9dc..09cdcdfe7e9 100644
--- a/net/sched/cls_api.c
+++ b/net/sched/cls_api.c
@@ -135,6 +135,7 @@ static int tc_ctl_tfilter(struct sk_buff *skb, struct nlmsghdr *n, void *arg)
unsigned long cl;
unsigned long fh;
int err;
+ int tp_created = 0;
if (net != &init_net)
return -EINVAL;
@@ -266,10 +267,7 @@ replay:
goto errout;
}
- spin_lock_bh(root_lock);
- tp->next = *back;
- *back = tp;
- spin_unlock_bh(root_lock);
+ tp_created = 1;
} else if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], tp->ops->kind))
goto errout;
@@ -296,8 +294,11 @@ replay:
switch (n->nlmsg_type) {
case RTM_NEWTFILTER:
err = -EEXIST;
- if (n->nlmsg_flags & NLM_F_EXCL)
+ if (n->nlmsg_flags & NLM_F_EXCL) {
+ if (tp_created)
+ tcf_destroy(tp);
goto errout;
+ }
break;
case RTM_DELTFILTER:
err = tp->ops->delete(tp, fh);
@@ -314,8 +315,18 @@ replay:
}
err = tp->ops->change(tp, cl, t->tcm_handle, tca, &fh);
- if (err == 0)
+ if (err == 0) {
+ if (tp_created) {
+ spin_lock_bh(root_lock);
+ tp->next = *back;
+ *back = tp;
+ spin_unlock_bh(root_lock);
+ }
tfilter_notify(skb, n, tp, fh, RTM_NEWTFILTER);
+ } else {
+ if (tp_created)
+ tcf_destroy(tp);
+ }
errout:
if (cl)