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| author | Minoru Usui <usui@mxm.nes.nec.co.jp> | 2009-06-02 02:17:34 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2009-06-02 02:17:34 -0700 |
| commit | 12186be7d2e1106cede1cc728526e3d7998cbe94 (patch) | |
| tree | a27e9c1cf720fbd31d67c27ea1426a0ae891733b /net | |
| parent | ea30e11970a96cfe5e32c03a29332554573b4a10 (diff) | |
| download | linux-12186be7d2e1106cede1cc728526e3d7998cbe94.tar.gz | |
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>
Diffstat (limited to 'net')
| -rw-r--r-- | net/sched/cls_api.c | 23 |
1 files changed, 17 insertions, 6 deletions
diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c index 0759f32e9dca..09cdcdfe7e91 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) |