From: Cong Wang <amwang@redhat.com>
Date: Thu, 27 Jun 2013 23:51:12 +0000 (+1000)
Subject: block/compat_ioctl.c: do not leak info to user-space
X-Git-Tag: next-20130628~3^2~615
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=7e4f24b89b9ce81014b21fec1524d933d0ba81f6;p=karo-tx-linux.git

block/compat_ioctl.c: do not leak info to user-space

There is a hole in struct hd_geometry, so we have to zero the struct on
stack before copying it to user-space.

Signed-off-by: Cong Wang <amwang@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

diff --git a/block/compat_ioctl.c b/block/compat_ioctl.c
index 7c668c8a6f95..7e5d474dc6ba 100644
--- a/block/compat_ioctl.c
+++ b/block/compat_ioctl.c
@@ -59,6 +59,7 @@ static int compat_hdio_getgeo(struct gendisk *disk, struct block_device *bdev,
 	if (!disk->fops->getgeo)
 		return -ENOTTY;
 
+	memset(&geo, 0, sizeof(geo));
 	/*
 	 * We need to set the startsect first, the driver may
 	 * want to override it.