Patch "cls_api.c: Fix dumping of non-existing actions' stats." has been added to the 3.18-stable tree

This is a note to let you know that I've just added the patch titled

cls_api.c: Fix dumping of non-existing actions' stats.

to the 3.18-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
cls_api.c-fix-dumping-of-non-existing-actions-stats.patch
and it can be found in the queue-3.18 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: =?UTF-8?q?Ignacy=20Gaw=C4=99dzki?=
<[email protected]>
Date: Tue, 3 Feb 2015 19:05:18 +0100
Subject: cls_api.c: Fix dumping of non-existing actions' stats.
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
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From: Ignacy Gawędzki <[email protected]>

commit b057df24a7536cce6c372efe9d0e3d1558afedf4 upstream.

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().

---
 net/sched/cls_api.c |    7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

@@ -563,8 +563,9 @@ void tcf_exts_change(struct tcf_proto *t
 }
 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)
 {

@@ -610,7 +611,7 @@ int tcf_exts_dump_stats(struct sk_buff *
 {
 #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;

Patches currently in stable-queue which might be from [email protected] are

queue-3.18/cls_api.c-fix-dumping-of-non-existing-actions-stats.patch