Messages in this thread Patch in this message | | | From | Vasiliy Kulikov <> | Subject | [PATCH] block: ioctl: fix information leak to userland | Date | Thu, 4 Nov 2010 17:48:15 +0300 |
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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> --- block/ioctl.c | 1 + 1 files changed, 1 insertions(+), 0 deletions(-)
diff --git a/block/ioctl.c b/block/ioctl.c index d724ceb..60bae81 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) -- 1.7.0.4
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