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| author | Ignacy Gawędzki <ignacy.gawedzki@green-communications.fr> | 2015-02-03 19:05:18 +0100 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2015-02-04 20:26:12 -0800 |
| commit | b057df24a7536cce6c372efe9d0e3d1558afedf4 (patch) | |
| tree | 4c062e5a5eb0c470ff686b741d85814ba66a593a /net/sched/cls_api.c | |
| parent | 3725a269815ba6dbb415feddc47da5af7d1fac58 (diff) | |
| download | lwn-b057df24a7536cce6c372efe9d0e3d1558afedf4.tar.gz lwn-b057df24a7536cce6c372efe9d0e3d1558afedf4.zip | |
cls_api.c: Fix dumping of non-existing actions' stats.
In tcf_exts_dump_stats(), ensure that exts->actions is not empty before
accessing the first element of that list and calling tcf_action_copy_stats()
on it. This fixes some random segvs when adding filters of type "basic" with
no particular action.
This also fixes the dumping of those "no-action" filters, which more often
than not made calls to tcf_action_copy_stats() fail and consequently netlink
attributes added by the caller to be removed by a call to nla_nest_cancel().
Fixes: 33be62715991 ("net_sched: act: use standard struct list_head")
Signed-off-by: Ignacy Gawędzki <ignacy.gawedzki@green-communications.fr>
Acked-by: Cong Wang <cwang@twopensource.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/sched/cls_api.c')
| -rw-r--r-- | net/sched/cls_api.c | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c index aad6a679fb13..baef987fe2c0 100644 --- a/net/sched/cls_api.c +++ b/net/sched/cls_api.c @@ -556,8 +556,9 @@ void tcf_exts_change(struct tcf_proto *tp, struct tcf_exts *dst, } EXPORT_SYMBOL(tcf_exts_change); -#define tcf_exts_first_act(ext) \ - list_first_entry(&(exts)->actions, struct tc_action, list) +#define tcf_exts_first_act(ext) \ + list_first_entry_or_null(&(exts)->actions, \ + struct tc_action, list) int tcf_exts_dump(struct sk_buff *skb, struct tcf_exts *exts) { @@ -603,7 +604,7 @@ int tcf_exts_dump_stats(struct sk_buff *skb, struct tcf_exts *exts) { #ifdef CONFIG_NET_CLS_ACT struct tc_action *a = tcf_exts_first_act(exts); - if (tcf_action_copy_stats(skb, a, 1) < 0) + if (a != NULL && tcf_action_copy_stats(skb, a, 1) < 0) return -1; #endif return 0; |