[ 3.5.y.z extended stable ] Patch "b43: stop format string leaking into error msgs" has been added to staging queue

[Luis Henriques]

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

    b43: stop format string leaking into error msgs

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 1ca947f893bafad505bbdb4b1fd928f3680cc4ff Mon Sep 17 00:00:00 2001
From: Kees Cook <keescook at chromium.org>
Date: Fri, 10 May 2013 14:48:21 -0700
Subject: [PATCH] b43: stop format string leaking into error msgs

commit e0e29b683d6784ef59bbc914eac85a04b650e63c upstream.

The module parameter "fwpostfix" is userspace controllable, unfiltered,
and is used to define the firmware filename. b43_do_request_fw() populates
ctx->errors[] on error, containing the firmware filename. b43err()
parses its arguments as a format string. For systems with b43 hardware,
this could lead to a uid-0 to ring-0 escalation.

CVE-2013-2852

Signed-off-by: Kees Cook <keescook at chromium.org>
Signed-off-by: John W. Linville <linville at tuxdriver.com>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 drivers/net/wireless/b43/main.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/wireless/b43/main.c b/drivers/net/wireless/b43/main.c
index f8fd420..5b349da 100644
--- a/drivers/net/wireless/b43/main.c
+++ b/drivers/net/wireless/b43/main.c
@@ -2451,7 +2451,7 @@ static void b43_request_firmware(struct work_struct *work)
 	for (i = 0; i < B43_NR_FWTYPES; i++) {
 		errmsg = ctx->errors[i];
 		if (strlen(errmsg))
-			b43err(dev->wl, errmsg);
+			b43err(dev->wl, "%s", errmsg);
 	}
 	b43_print_fw_helptext(dev->wl, 1);
 	goto out;
--
1.8.1.2