[PATCH 4.8 059/138] vt: clear selection before resizing

[Greg Kroah-Hartman]

4.8-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Scot Doyle <lkml14@xxxxxxxxxxxxx>

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@xxxxxxxxxxxxxx

Reported-and-tested-by: Dmitry Vyukov <dvyukov@xxxxxxxxxx>
Signed-off-by: Scot Doyle <lkml14@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/tty/vt/vt.c |    3 +++
 1 file changed, 3 insertions(+)

--- a/drivers/tty/vt/vt.c
+++ b/drivers/tty/vt/vt.c
@@ -874,6 +874,9 @@ 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;