From: Cong Wang <amwang@redhat.com>
Date: Wed, 3 Jul 2013 22:01:12 +0000 (-0700)
Subject: block/compat_ioctl.c: do not leak info to user-space
X-Git-Tag: v3.11-rc1~99^2~418
X-Git-Url: https://asedeno.scripts.mit.edu/gitweb/?a=commitdiff_plain;h=8b0d77f13192678019f07cbc6b3338d6d91f1cf4;p=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>
Signed-off-by: Linus Torvalds <torvalds@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.