[3.11.y.z extended stable] Patch "mtd: sm_ftl: heap corruption in sm_create_sysfs_attributes()" has been added to staging queue

[Luis Henriques]

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

    mtd: sm_ftl: heap corruption in sm_create_sysfs_attributes()

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 7b23ad152fdc7515cee9f1bb4be6d006e77ed74a Mon Sep 17 00:00:00 2001
From: Dan Carpenter <dan.carpenter at oracle.com>
Date: Thu, 5 Dec 2013 17:53:50 +0300
Subject: mtd: sm_ftl: heap corruption in sm_create_sysfs_attributes()

commit b4c233057771581698a13694ab6f33b48ce837dc upstream.

We always put a NUL terminator one space past the end of the "vendor"
buffer.  Walter Harms also pointed out that this should just use
kstrndup().

Fixes: 7d17c02a01a1 ('mtd: Add new SmartMedia/xD FTL')

Signed-off-by: Dan Carpenter <dan.carpenter at oracle.com>
Signed-off-by: Brian Norris <computersforpeace at gmail.com>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 drivers/mtd/sm_ftl.c | 11 ++++-------
 1 file changed, 4 insertions(+), 7 deletions(-)

diff --git a/drivers/mtd/sm_ftl.c b/drivers/mtd/sm_ftl.c
index f9d5615..4b55cd4 100644
--- a/drivers/mtd/sm_ftl.c
+++ b/drivers/mtd/sm_ftl.c
@@ -59,15 +59,12 @@ struct attribute_group *sm_create_sysfs_attributes(struct sm_ftl *ftl)
 	struct attribute_group *attr_group;
 	struct attribute **attributes;
 	struct sm_sysfs_attribute *vendor_attribute;
+	char *vendor;

-	int vendor_len = strnlen(ftl->cis_buffer + SM_CIS_VENDOR_OFFSET,
-					SM_SMALL_PAGE - SM_CIS_VENDOR_OFFSET);
-
-	char *vendor = kmalloc(vendor_len, GFP_KERNEL);
+	vendor = kstrndup(ftl->cis_buffer + SM_CIS_VENDOR_OFFSET,
+			  SM_SMALL_PAGE - SM_CIS_VENDOR_OFFSET, GFP_KERNEL);
 	if (!vendor)
 		goto error1;
-	memcpy(vendor, ftl->cis_buffer + SM_CIS_VENDOR_OFFSET, vendor_len);
-	vendor[vendor_len] = 0;

 	/* Initialize sysfs attributes */
 	vendor_attribute =
@@ -78,7 +75,7 @@ struct attribute_group *sm_create_sysfs_attributes(struct sm_ftl *ftl)
 	sysfs_attr_init(&vendor_attribute->dev_attr.attr);

 	vendor_attribute->data = vendor;
-	vendor_attribute->len = vendor_len;
+	vendor_attribute->len = strlen(vendor);
 	vendor_attribute->dev_attr.attr.name = "vendor";
 	vendor_attribute->dev_attr.attr.mode = S_IRUGO;
 	vendor_attribute->dev_attr.show = sm_attr_show;
--
1.9.1