[3.5.y.z extended stable] Patch "libertas: potential oops in debugfs" has been added to staging queue

Luis Henriques luis.henriques at canonical.com
Fri Nov 29 14:02:10 UTC 2013

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

    libertas: potential oops in debugfs

to the linux-3.5.y-queue branch of the 3.5.y.z extended stable tree 
which can be found at:


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



>From 0ad3ba836938c5b052ac8b1b07f0cd6e36272583 Mon Sep 17 00:00:00 2001
From: Dan Carpenter <dan.carpenter at oracle.com>
Date: Wed, 30 Oct 2013 20:12:51 +0300
Subject: libertas: potential oops in debugfs

commit a497e47d4aec37aaf8f13509f3ef3d1f6a717d88 upstream.

If we do a zero size allocation then it will oops.  Also we can't be
sure the user passes us a NUL terminated string so I've added a

This code can only be triggered by root.

Reported-by: Nico Golde <nico at ngolde.de>
Reported-by: Fabian Yamaguchi <fabs at goesec.de>
Signed-off-by: Dan Carpenter <dan.carpenter at oracle.com>
Acked-by: Dan Williams <dcbw at redhat.com>
Signed-off-by: John W. Linville <linville at tuxdriver.com>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
 drivers/net/wireless/libertas/debugfs.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/net/wireless/libertas/debugfs.c b/drivers/net/wireless/libertas/debugfs.c
index a06cc28..0b48430 100644
--- a/drivers/net/wireless/libertas/debugfs.c
+++ b/drivers/net/wireless/libertas/debugfs.c
@@ -913,7 +913,10 @@ static ssize_t lbs_debugfs_write(struct file *f, const char __user *buf,
 	char *p2;
 	struct debug_data *d = f->private_data;

-	pdata = kmalloc(cnt, GFP_KERNEL);
+	if (cnt == 0)
+		return 0;
+	pdata = kmalloc(cnt + 1, GFP_KERNEL);
 	if (pdata == NULL)
 		return 0;

@@ -922,6 +925,7 @@ static ssize_t lbs_debugfs_write(struct file *f, const char __user *buf,
 		return 0;
+	pdata[cnt] = '\0';

 	p0 = pdata;
 	for (i = 0; i < num_of_items; i++) {

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