Patch "connector: bump skb->users before callback invocation" has been added to the 4.3-stable tree

Patch "connector: bump skb->users before callback invocation" has been added to the 4.3-stable tree

[gregkh]

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

    connector: bump skb->users before callback invocation

to the 4.3-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:
     connector-bump-skb-users-before-callback-invocation.patch
and it can be found in the queue-4.3 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From foo@baz Tue Jan 26 21:35:03 PST 2016
From: Florian Westphal <fw@strlen.de>
Date: Thu, 31 Dec 2015 14:26:33 +0100
Subject: connector: bump skb->users before callback invocation

From: Florian Westphal <fw@strlen.de>

[ Upstream commit 55285bf09427c5abf43ee1d54e892f352092b1f1 ]

Dmitry reports memleak with syskaller program.
Problem is that connector bumps skb usecount but might not invoke callback.

So move skb_get to where we invoke the callback.

Reported-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/connector/connector.c |   11 +++--------
 1 file changed, 3 insertions(+), 8 deletions(-)

--- a/drivers/connector/connector.c
+++ b/drivers/connector/connector.c
@@ -178,26 +178,21 @@ static int cn_call_callback(struct sk_bu
  *
  * It checks skb, netlink header and msg sizes, and calls callback helper.
  */
-static void cn_rx_skb(struct sk_buff *__skb)
+static void cn_rx_skb(struct sk_buff *skb)
 {
 	struct nlmsghdr *nlh;
-	struct sk_buff *skb;
 	int len, err;
 
-	skb = skb_get(__skb);
-
 	if (skb->len >= NLMSG_HDRLEN) {
 		nlh = nlmsg_hdr(skb);
 		len = nlmsg_len(nlh);
 
 		if (len < (int)sizeof(struct cn_msg) ||
 		    skb->len < nlh->nlmsg_len ||
-		    len > CONNECTOR_MAX_MSG_SIZE) {
-			kfree_skb(skb);
+		    len > CONNECTOR_MAX_MSG_SIZE)
 			return;
-		}
 
-		err = cn_call_callback(skb);
+		err = cn_call_callback(skb_get(skb));
 		if (err < 0)
 			kfree_skb(skb);
 	}


Patches currently in stable-queue which might be from fw@strlen.de are

queue-4.3/connector-bump-skb-users-before-callback-invocation.patch