[PATCH 3.16 172/306] vt: clear selection before resizing

Ben Hutchings
2017-02-15T23:35:48Z

From: Scot Doyle <lkml14@scotdoyle.com>

commit 009e39ae44f4191188aeb6dfbf661b771dbbe515 upstream.

When resizing a vt its selection may exceed the new size, resulting in
an invalid memory access [1]. Clear the selection before resizing.

[1] http://lkml.kernel.org/r/CACT4Y+acDTwy4umEvf5ROBGiRJNrxHN4Cn5szCXE5Jw-d1B=Xw@mail.gmail.com

Reported-and-tested-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Scot Doyle <lkml14@scotdoyle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
drivers/tty/vt/vt.c | 3 +++
1 file changed, 3 insertions(+)

--- a/drivers/tty/vt/vt.c
+++ b/drivers/tty/vt/vt.c
@@ -869,6 +869,9 @@ static int vc_do_resize(struct tty_struc
if (!newscreen)
return -ENOMEM;

+ if (vc == sel_cons)
+ clear_selection();
+
old_rows = vc->vc_rows;
old_row_size = vc->vc_size_row;