From patchwork Thu Jun 2 20:06:28 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Helge Deller X-Patchwork-Id: 12868101 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 81F32C433EF for ; Thu, 2 Jun 2022 20:06:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236813AbiFBUGm (ORCPT ); Thu, 2 Jun 2022 16:06:42 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47864 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239185AbiFBUGg (ORCPT ); Thu, 2 Jun 2022 16:06:36 -0400 Received: from mout.gmx.net (mout.gmx.net [212.227.15.19]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3C26036B4C for ; Thu, 2 Jun 2022 13:06:33 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gmx.net; s=badeba3b8450; t=1654200389; bh=IsKF4iCBq0sNXJ6MjC82oLlWI1Yp1QCRZB0HT/WCHFA=; h=X-UI-Sender-Class:Date:From:To:Subject; b=HEezxHjVRfLjrC3TUCgjSiWUCHqIaIpSqy3gj6uBC1XFmghmJgL1otT8SC9OQ7aox tQoS3wxWd0Rlq7XMhrs3eqNkL5jjO7wTdrD92a9s+1ZUMNBbTpVEIEQn9GkJsHhqXu a9pLGmv/M+swC/Mt4umO1NwwE+su8KoadKWzCR90= X-UI-Sender-Class: 01bb95c1-4bf8-414a-932a-4f6e2808ef9c Received: from p100 ([92.116.181.14]) by mail.gmx.net (mrgmx005 [212.227.17.190]) with ESMTPSA (Nemesis) id 1MpUZ4-1nR6mf3Cm4-00pwLE; Thu, 02 Jun 2022 22:06:29 +0200 Date: Thu, 2 Jun 2022 22:06:28 +0200 From: Helge Deller To: linux-fbdev@vger.kernel.org, dri-devel@lists.freedesktop.org Subject: [PATCH] fbcon: Fix boundary checks for fbcon=vc:n1-n2 parameters Message-ID: MIME-Version: 1.0 Content-Disposition: inline X-Provags-ID: V03:K1:Riat3W15xiHyRug7/i3UOhBY6b3BVi8Fws7yM36g2DKuCHT987m HmkkSWw0+riUMm4n2dBMVcsoQDrNFg/mfQR6hHU6nUcc0bcDXqjU3hhwH/CS7J3xrzM4Sf1 0o//kE9I3vZTsvUJCd92u9lwWe8hwNS3SDuroz8baSxuBob4wo1+cpKU5JkxJLsfrAwfYjm xoVwsTdykeoPCXZ25vRqg== X-UI-Out-Filterresults: notjunk:1;V03:K0:MDYflrGxj5o=:2usV/A+HCeXBPglhWE8d/A nQQYXL9Wh+raURLV+shdiK80UTXujkGOSwYsKB08gguZG9ZFyE1CUkb4Ecj6jCFx3kIhRFnMH 4+gRq0cvY7SWhQQEVokvjuGUIqLXu/3OdZjl2tfTrdC65c1eYKgrwu0XgT5eWpBGHBg5gbjmR +Jj5diSQDfvDQNcVR4ON0F0L7woK9PF+TyOPjo6ms1rdUOqAZyoK3fImsFkw4702RJeYGWJDr nWrPSiAckRqJJgQ+kDVIWxCUxnSbySbgkyuzW7Oxdhe5750VP2VaubOlodFgOSpZxe9OQluyU DBU7mq9b9pAkJOuC+W59lFsUQZeex/aw57/r493jYPM2fuXmbrhE2lwUy/o2Chj6FYpbJ7vV6 X/l0FonX7i4SNao+zoWsYBobCcoRJznZjK/qoeN7Drmx34HX8dUDg3xkz1cgo8c6aUA0j4BSZ xXkuyb08PPt/K+plo70jzbcoWiAkuRzeM3vr5l3vjCfHh8GJPoAywv9kB1LXi5pMqkTmHSnwy yhC3bidi6LUf/g/PQINdHVZPEqz3XtGgOKwkuCxGAoOYm4alrjtV7w5w5BkV4qb04uepzKF+s GBpzf+qvldRtY6SXDMyjU6jzXHsatRnXmXzDad++cURJdvwyL+akICrX3Nlhlcg0Rya6h0GjR lTJw7xfxZi/3Fb+0X3dCddCZpDqlXp0x+QJSneUaQNjUzvW0N3ivfYgqUVtuj3asJGa3vsxWm TgxXzeaFttP/4fsG9VIXIxhqIYCYY0oaVVC3XtpSNyKvU1REY/f18CqOPTb1e0vL6Jd3f8Dci p9efiBrwnjh58FGLdZQ7wTsXT7II9en8A0BktVXg9Rx5cxVrBeqy0bVRLxXTwDYa3cIcQuT0y TpGJdW+dqCeml19opqmTwrkGJg4GDPe0b6hXw0mSI0yrTNsv1t+U9ZTV092YIreIOxJX/Xfqs G4Z0zw8kwvEW1emYVWxmf7RKTnbRJrVoJswioLItqVLvxF1D1YTiy6yRSV11ypOrkeGXF5IoR mWR13OZy621B1wOXmgorphlpgbPoRWihhRCHAhemypwmHaHbClhtQ4nWAMjUEYbNdlPNJh1fe ooKXMFXgTlCAm5eni/xO6OpzOiwFLmPSBviFBpB5NbyCqO2eoskNqdpVA== Precedence: bulk List-ID: X-Mailing-List: linux-fbdev@vger.kernel.org The user may use the fbcon=vc:- option to tell fbcon to take over the given range (n1...n2) of consoles. The value for n1 and n2 needs to be a positive number and up to (MAX_NR_CONSOLES - 1). The given values were not fully checked against those boundaries yet. To fix the issue, convert first_fb_vc and last_fb_vc to unsigned integers and check them against the upper boundary, and make sure that first_fb_vc is smaller than last_fb_vc. Signed-off-by: Helge Deller Cc: stable@vger.kernel.org Reviewed-by: Daniel Vetter diff --git a/drivers/video/fbdev/core/fbcon.c b/drivers/video/fbdev/core/fbcon.c index 2fc1b80a26ad..c2f9e5711c39 100644 --- a/drivers/video/fbdev/core/fbcon.c +++ b/drivers/video/fbdev/core/fbcon.c @@ -115,8 +115,8 @@ static int logo_lines; enums. */ static int logo_shown = FBCON_LOGO_CANSHOW; /* console mappings */ -static int first_fb_vc; -static int last_fb_vc = MAX_NR_CONSOLES - 1; +static unsigned int first_fb_vc; +static unsigned int last_fb_vc = MAX_NR_CONSOLES - 1; static int fbcon_is_default = 1; static int primary_device = -1; static int fbcon_has_console_bind; @@ -464,10 +464,12 @@ static int __init fb_console_setup(char *this_opt) options += 3; if (*options) first_fb_vc = simple_strtoul(options, &options, 10) - 1; - if (first_fb_vc < 0) + if (first_fb_vc >= MAX_NR_CONSOLES) first_fb_vc = 0; if (*options++ == '-') last_fb_vc = simple_strtoul(options, &options, 10) - 1; + if (last_fb_vc < first_fb_vc || last_fb_vc >= MAX_NR_CONSOLES) + last_fb_vc = MAX_NR_CONSOLES - 1; fbcon_is_default = 0; continue; }