Patch "mmc: block: fix free of uninitialized 'idata->buf'" has been added to the 4.6-stable tree

Patch "mmc: block: fix free of uninitialized 'idata->buf'" has been added to the 4.6-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    mmc: block: fix free of uninitialized 'idata->buf'

to the 4.6-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     mmc-block-fix-free-of-uninitialized-idata-buf.patch
and it can be found in the queue-4.6 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From bfe5b1b1e013f7b1c0fd2ac3b3c8c380114b3fb9 Mon Sep 17 00:00:00 2001
From: Ville Viinikka <ville@tuxera.com>
Date: Fri, 8 Jul 2016 18:27:02 +0300
Subject: mmc: block: fix free of uninitialized 'idata->buf'

From: Ville Viinikka <ville@tuxera.com>

commit bfe5b1b1e013f7b1c0fd2ac3b3c8c380114b3fb9 upstream.

Set 'idata->buf' to NULL so that it never gets returned without
initialization. This fixes a bug where mmc_blk_ioctl_cmd() would
free both 'idata' and 'idata->buf' but 'idata->buf' was returned
uninitialized.

Fixes: 1ff8950c0433 ("mmc: block: change to use kmalloc when copy data from userspace")
Signed-off-by: Ville Viinikka <ville@tuxera.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/mmc/card/block.c |    4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

--- a/drivers/mmc/card/block.c
+++ b/drivers/mmc/card/block.c
@@ -352,8 +352,10 @@ static struct mmc_blk_ioc_data *mmc_blk_
 		goto idata_err;
 	}
 
-	if (!idata->buf_bytes)
+	if (!idata->buf_bytes) {
+		idata->buf = NULL;
 		return idata;
+	}
 
 	idata->buf = kmalloc(idata->buf_bytes, GFP_KERNEL);
 	if (!idata->buf) {


Patches currently in stable-queue which might be from ville@tuxera.com are

queue-4.6/mmc-block-fix-free-of-uninitialized-idata-buf.patch