[3.5.y.z extended stable] Patch "connector: use nlmsg_len() to check message length" has been added to staging queue

Luis Henriques luis.henriques at canonical.com
Mon Oct 28 10:30:24 UTC 2013


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

    connector: use nlmsg_len() to check message length

to the linux-3.5.y-queue branch of the 3.5.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-3.5.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 3.5.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

------

>From dfe65679cb5695679093dd08ef1b6bbf9cca025e Mon Sep 17 00:00:00 2001
From: Mathias Krause <minipli at googlemail.com>
Date: Mon, 30 Sep 2013 22:03:07 +0200
Subject: [PATCH] connector: use nlmsg_len() to check message length

commit 162b2bedc084d2d908a04c93383ba02348b648b0 upstream.

The current code tests the length of the whole netlink message to be
at least as long to fit a cn_msg. This is wrong as nlmsg_len includes
the length of the netlink message header. Use nlmsg_len() instead to
fix this "off-by-NLMSG_HDRLEN" size check.

Signed-off-by: Mathias Krause <minipli at googlemail.com>
Signed-off-by: David S. Miller <davem at davemloft.net>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 drivers/connector/connector.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/connector/connector.c b/drivers/connector/connector.c
index dde6a0f..ea6efe8 100644
--- a/drivers/connector/connector.c
+++ b/drivers/connector/connector.c
@@ -157,17 +157,18 @@ static int cn_call_callback(struct sk_buff *skb)
 static void cn_rx_skb(struct sk_buff *__skb)
 {
 	struct nlmsghdr *nlh;
-	int err;
 	struct sk_buff *skb;
+	int len, err;

 	skb = skb_get(__skb);

 	if (skb->len >= NLMSG_SPACE(0)) {
 		nlh = nlmsg_hdr(skb);
+		len = nlmsg_len(nlh);

-		if (nlh->nlmsg_len < sizeof(struct cn_msg) ||
+		if (len < (int)sizeof(struct cn_msg) ||
 		    skb->len < nlh->nlmsg_len ||
-		    nlh->nlmsg_len > CONNECTOR_MAX_MSG_SIZE) {
+		    len > CONNECTOR_MAX_MSG_SIZE) {
 			kfree_skb(skb);
 			return;
 		}
--
1.8.3.2





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