[3.19.y-ckt stable] Patch "ipvlan: fix leak in ipvlan_rcv_frame" has been added to staging queue

[Kamal Mostafa]

This is a note to let you know that I have just added a patch titled

    ipvlan: fix leak in ipvlan_rcv_frame

to the linux-3.19.y-queue branch of the 3.19.y-ckt extended stable tree 
which can be found at:

    http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.19.y-queue

This patch is scheduled to be released in version 3.19.8-ckt12.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.19.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

------

>From 96635ee91a0107a5580ed8bcf58660ba709f7167 Mon Sep 17 00:00:00 2001
From: Sabrina Dubroca <sd at queasysnail.net>
Date: Mon, 16 Nov 2015 22:34:26 +0100
Subject: ipvlan: fix leak in ipvlan_rcv_frame

commit cf554ada0be7077906aa9a17faf151ff66e3cb8e upstream.

Pass a **skb to ipvlan_rcv_frame so that if skb_share_check returns a
new skb, we actually use it during further processing.

It's safe to ignore the new skb in the ipvlan_xmit_* functions, because
they call ipvlan_rcv_frame with local == true, so that dev_forward_skb
is called and always takes ownership of the skb.

Fixes: 2ad7bf363841 ("ipvlan: Initial check-in of the IPVLAN driver.")
Signed-off-by: Sabrina Dubroca <sd at queasysnail.net>
Signed-off-by: David S. Miller <davem at davemloft.net>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 drivers/net/ipvlan/ipvlan_core.c | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/drivers/net/ipvlan/ipvlan_core.c b/drivers/net/ipvlan/ipvlan_core.c
index 8df3268..edf9ed8 100644
--- a/drivers/net/ipvlan/ipvlan_core.c
+++ b/drivers/net/ipvlan/ipvlan_core.c
@@ -237,7 +237,7 @@ mcast_acct:
 	}
 }

-static int ipvlan_rcv_frame(struct ipvl_addr *addr, struct sk_buff *skb,
+static int ipvlan_rcv_frame(struct ipvl_addr *addr, struct sk_buff **pskb,
 			    bool local)
 {
 	struct ipvl_dev *ipvlan = addr->master;
@@ -245,6 +245,7 @@ static int ipvlan_rcv_frame(struct ipvl_addr *addr, struct sk_buff *skb,
 	unsigned int len;
 	rx_handler_result_t ret = RX_HANDLER_CONSUMED;
 	bool success = false;
+	struct sk_buff *skb = *pskb;

 	len = skb->len + ETH_HLEN;
 	if (unlikely(!(dev->flags & IFF_UP))) {
@@ -256,6 +257,7 @@ static int ipvlan_rcv_frame(struct ipvl_addr *addr, struct sk_buff *skb,
 	if (!skb)
 		goto out;

+	*pskb = skb;
 	skb->dev = dev;
 	skb->pkt_type = PACKET_HOST;

@@ -447,7 +449,7 @@ static int ipvlan_xmit_mode_l3(struct sk_buff *skb, struct net_device *dev)

 	addr = ipvlan_addr_lookup(ipvlan->port, lyr3h, addr_type, true);
 	if (addr)
-		return ipvlan_rcv_frame(addr, skb, true);
+		return ipvlan_rcv_frame(addr, &skb, true);

 out:
 	skb->dev = ipvlan->phy_dev;
@@ -467,7 +469,7 @@ static int ipvlan_xmit_mode_l2(struct sk_buff *skb, struct net_device *dev)
 		if (lyr3h) {
 			addr = ipvlan_addr_lookup(ipvlan->port, lyr3h, addr_type, true);
 			if (addr)
-				return ipvlan_rcv_frame(addr, skb, true);
+				return ipvlan_rcv_frame(addr, &skb, true);
 		}
 		skb = skb_share_check(skb, GFP_ATOMIC);
 		if (!skb)
@@ -553,7 +555,7 @@ static rx_handler_result_t ipvlan_handle_mode_l3(struct sk_buff **pskb,

 	addr = ipvlan_addr_lookup(port, lyr3h, addr_type, true);
 	if (addr)
-		ret = ipvlan_rcv_frame(addr, skb, false);
+		ret = ipvlan_rcv_frame(addr, pskb, false);

 out:
 	return ret;
@@ -580,7 +582,7 @@ static rx_handler_result_t ipvlan_handle_mode_l2(struct sk_buff **pskb,

 		addr = ipvlan_addr_lookup(port, lyr3h, addr_type, true);
 		if (addr)
-			ret = ipvlan_rcv_frame(addr, skb, false);
+			ret = ipvlan_rcv_frame(addr, pskb, false);
 	}

 	return ret;
--
1.9.1