Attachment 487076 Details for Bug 684261 – Proposed fix

[patch] Proposed fix

0001-Clean-console-safely.patch (text/plain), 1.31 KB, created by Petr Pisar on 2011-03-23 15:47:52 UTC

(hide)

Description:

Filename:

MIME Type:

Creator: Petr Pisar

Created: 2011-03-23 15:47:52 UTC

Size: 1.31 KB

patch

obsolete

>From 9d0c14a8b5fa0dc965e8d88b84ad42c87f25dd8a Mon Sep 17 00:00:00 2001
>From: =?UTF-8?q?Petr=20P=C3=ADsa=C5=99?= <ppisar@redhat.com>
>Date: Wed, 23 Mar 2011 16:36:32 +0100
>Subject: [PATCH] Clean console safely
>
>Traditional \E[2J sequence erases console display but scroll-back
>buffer and underlying device (frame) buffer keeps data that can be
>accessed by scrolling console back.
>
>This patch introduce new \E[J parameter 3 that allows to scramble
>scroll-back buffer explicitly. Session locking programs (screen,
>vlock) can use it to prevent attacker to browse locked console
>history.
>---
> drivers/tty/vt/vt.c |    6 ++++++
> 1 files changed, 6 insertions(+), 0 deletions(-)
>
>diff --git a/drivers/tty/vt/vt.c b/drivers/tty/vt/vt.c
>index 147ede3..c31bf2a 100644
>--- a/drivers/tty/vt/vt.c
>+++ b/drivers/tty/vt/vt.c
>@@ -1198,6 +1198,12 @@ static void csi_J(struct vc_data *vc, int vpar)
> 					      vc->vc_x + 1);
> 			}
> 			break;
>+        case 3: /* erase scroll-back buffer (and whole display) */
>+            scr_memsetw(vc->vc_screenbuf, vc->vc_video_erase_char,
>+                    vc->vc_screenbuf_size >> 1);
>+            set_origin(vc);
>+            if (CON_IS_VISIBLE(vc))
>+                update_screen(vc);
> 		case 2: /* erase whole display */
> 			count = vc->vc_cols * vc->vc_rows;
> 			start = (unsigned short *)vc->vc_origin;
>-- 
>1.7.4
>

Actions: View | Diff

Attachments on bug 684261: 487076