path: root/block
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authorVasiliy Kulikov <segooon@gmail.com>2010-11-08 14:42:40 +0100
committerJens Axboe <jaxboe@fusionio.com>2010-11-10 14:40:53 +0100
commita014741c0adfb8fb79952939ca087cf03d272bb9 (patch)
tree57bafa05736f172b94fde156bb51798b3ddb6107 /block
parent77304d2abac6101f7249754ffdd4421258877ab0 (diff)
block: ioctl: fix information leak to userland
Structure hd_geometry is copied to userland with 4 padding bytes between cylinders and start fields uninitialized on 64-bit platforms. It leads to leaking of contents of kernel stack memory. Currently there is no memset() in real implementations of getgeo() in drivers/block/, so it makes sense to have memset() in blkdev_ioctl(). Signed-off-by: Vasiliy Kulikov <segooon@gmail.com> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
Diffstat (limited to 'block')
1 files changed, 1 insertions, 0 deletions
diff --git a/block/ioctl.c b/block/ioctl.c
index 38aa194f63e..3d866d0037f 100644
--- a/block/ioctl.c
+++ b/block/ioctl.c
@@ -242,6 +242,7 @@ int blkdev_ioctl(struct block_device *bdev, fmode_t mode, unsigned cmd,
* We need to set the startsect first, the driver may
* want to override it.
+ memset(&geo, 0, sizeof(geo));
geo.start = get_start_sect(bdev);
ret = disk->fops->getgeo(bdev, &geo);
if (ret)