[3.11.y.z extended stable] Patch "net: rose: restore old recvmsg behavior" has been added to staging queue

[Luis Henriques]

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

    net: rose: restore old recvmsg behavior

to the linux-3.11.y-queue branch of the 3.11.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.11.y-queue

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

For more information about the 3.11.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

------

>From 3d2d6e4feaa06df6f1247dd4207cf25bde3d91be Mon Sep 17 00:00:00 2001
From: Florian Westphal <fw at strlen.de>
Date: Mon, 23 Dec 2013 00:32:31 +0100
Subject: net: rose: restore old recvmsg behavior

commit f81152e35001e91997ec74a7b4e040e6ab0acccf upstream.

recvmsg handler in net/rose/af_rose.c performs size-check ->msg_namelen.

After commit f3d3342602f8bcbf37d7c46641cb9bca7618eb1c
(net: rework recvmsg handler msg_name and msg_namelen logic), we now
always take the else branch due to namelen being initialized to 0.

Digging in netdev-vger-cvs git repo shows that msg_namelen was
initialized with a fixed-size since at least 1995, so the else branch
was never taken.

Compile tested only.

Signed-off-by: Florian Westphal <fw at strlen.de>
Acked-by: Hannes Frederic Sowa <hannes at stressinduktion.org>
Signed-off-by: David S. Miller <davem at davemloft.net>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 net/rose/af_rose.c | 16 ++++------------
 1 file changed, 4 insertions(+), 12 deletions(-)

diff --git a/net/rose/af_rose.c b/net/rose/af_rose.c
index 33af772..62ced65 100644
--- a/net/rose/af_rose.c
+++ b/net/rose/af_rose.c
@@ -1253,6 +1253,7 @@ static int rose_recvmsg(struct kiocb *iocb, struct socket *sock,

 	if (msg->msg_name) {
 		struct sockaddr_rose *srose;
+		struct full_sockaddr_rose *full_srose = msg->msg_name;

 		memset(msg->msg_name, 0, sizeof(struct full_sockaddr_rose));
 		srose = msg->msg_name;
@@ -1260,18 +1261,9 @@ static int rose_recvmsg(struct kiocb *iocb, struct socket *sock,
 		srose->srose_addr   = rose->dest_addr;
 		srose->srose_call   = rose->dest_call;
 		srose->srose_ndigis = rose->dest_ndigis;
-		if (msg->msg_namelen >= sizeof(struct full_sockaddr_rose)) {
-			struct full_sockaddr_rose *full_srose = (struct full_sockaddr_rose *)msg->msg_name;
-			for (n = 0 ; n < rose->dest_ndigis ; n++)
-				full_srose->srose_digis[n] = rose->dest_digis[n];
-			msg->msg_namelen = sizeof(struct full_sockaddr_rose);
-		} else {
-			if (rose->dest_ndigis >= 1) {
-				srose->srose_ndigis = 1;
-				srose->srose_digi = rose->dest_digis[0];
-			}
-			msg->msg_namelen = sizeof(struct sockaddr_rose);
-		}
+		for (n = 0 ; n < rose->dest_ndigis ; n++)
+			full_srose->srose_digis[n] = rose->dest_digis[n];
+		msg->msg_namelen = sizeof(struct full_sockaddr_rose);
 	}

 	skb_free_datagram(sk, skb);
--
1.8.3.2