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 7c668c8..7e5d474d 100644
--- a/block/compat_ioctl.c
+++ b/block/compat_ioctl.c
@@ -59,6 +59,7 @@
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.