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

[Kamal Mostafa]

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-3.8.y-queue branch of the 3.8.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-3.8.y-queue

This patch is scheduled to be released in version 3.8.13.16.

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

For more information about the 3.8.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

------

>From e75b569b534369bee669dd68734b50211593967a 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

[ Upstream commit f81152e35001e91997ec74a7b4e040e6ab0acccf ]

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: Kamal Mostafa <kamal 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 ce5f5b9..bde7d69 100644
--- a/net/rose/af_rose.c
+++ b/net/rose/af_rose.c
@@ -1257,6 +1257,7 @@ 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;
@@ -1264,18 +1265,9 @@ 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