From: Scot Doyle <lkml14@scotdoyle.com>
Date: Thu, 13 Oct 2016 17:12:43 +0000 (-0500)
Subject: vt: clear selection before resizing
X-Git-Tag: v3.16.40~135
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=dbc3fd44f957a39407e889287bf61fa0ef3ecc14;p=thirdparty%2Fkernel%2Fstable.git

vt: clear selection before resizing

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>
---

diff --git a/drivers/tty/vt/vt.c b/drivers/tty/vt/vt.c
index 2bde9d7062e2c..a57f3761ab474 100644
--- a/drivers/tty/vt/vt.c
+++ b/drivers/tty/vt/vt.c
@@ -869,6 +869,9 @@ static int vc_do_resize(struct tty_struct *tty, struct vc_data *vc,
 	if (!newscreen)
 		return -ENOMEM;
 
+	if (vc == sel_cons)
+		clear_selection();
+
 	old_rows = vc->vc_rows;
 	old_row_size = vc->vc_size_row;