tree 5c04d74c91af1d1a312030921042f433a7e8942a
parent 13aa0a12183f804d95c4c5c4d09df19ea74eb424
author Nicolas Pitre <nicolas.pitre@linaro.org> 1531973125 -0400
committer Greg Kroah-Hartman <gregkh@linuxfoundation.org> 1532157586 +0200

vt: avoid a VLA in the unicode screen scroll function

The nr argument is typically small: most often nr == 1. However this
could be abused with a very large explicit scroll in a resized screen.
Make the code scroll lines by performing an array rotation operation to
avoid the need for a large temporary space.

Requested-by: Kees Cook <keescook@chromium.org>
Suggested-by: Adam Borowski <kilobyte@angband.pl>
Signed-off-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>