From patchwork Wed Feb 26 19:58:26 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Colin King X-Patchwork-Id: 11407121 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 4A2DE92A for ; Wed, 26 Feb 2020 19:58:34 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 2DB3D222C4 for ; Wed, 26 Feb 2020 19:58:34 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2DB3D222C4 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=canonical.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=dri-devel-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 1B71E6EB9E; Wed, 26 Feb 2020 19:58:33 +0000 (UTC) X-Original-To: dri-devel@lists.freedesktop.org Delivered-To: dri-devel@lists.freedesktop.org Received: from youngberry.canonical.com (youngberry.canonical.com [91.189.89.112]) by gabe.freedesktop.org (Postfix) with ESMTPS id D0D0E6EB9E for ; Wed, 26 Feb 2020 19:58:31 +0000 (UTC) Received: from 1.general.cking.uk.vpn ([10.172.193.212] helo=localhost) by youngberry.canonical.com with esmtpsa (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.86_2) (envelope-from ) id 1j72p8-0000Jj-K4; Wed, 26 Feb 2020 19:58:26 +0000 From: Colin King To: Lee Jones , Daniel Thompson , Jingoo Han , Bartlomiej Zolnierkiewicz , Gyungoh Yoo , Bryan Wu , dri-devel@lists.freedesktop.org, linux-fbdev@vger.kernel.org Subject: [PATCH][V2] backlight: sky81452: insure while loop does not allow negative array indexing Date: Wed, 26 Feb 2020 19:58:26 +0000 Message-Id: <20200226195826.6567-1-colin.king@canonical.com> X-Mailer: git-send-email 2.25.0 MIME-Version: 1.0 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: kernel-janitors@vger.kernel.org, linux-kernel@vger.kernel.org Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" From: Colin Ian King In the unlikely event that num_entry is zero, the while loop pre-decrements num_entry to cause negative array indexing into the array sources. Fix this by iterating only if num_entry >= 0. Addresses-Coverity: ("Out-of-bounds read") Fixes: f705806c9f35 ("backlight: Add support Skyworks SKY81452 backlight driver") Signed-off-by: Colin Ian King --- V2: fix typo in commit subject line --- drivers/video/backlight/sky81452-backlight.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/video/backlight/sky81452-backlight.c b/drivers/video/backlight/sky81452-backlight.c index 2355f00f5773..f456930ce78e 100644 --- a/drivers/video/backlight/sky81452-backlight.c +++ b/drivers/video/backlight/sky81452-backlight.c @@ -200,7 +200,7 @@ static struct sky81452_bl_platform_data *sky81452_bl_parse_dt( } pdata->enable = 0; - while (--num_entry) + while (--num_entry >= 0) pdata->enable |= (1 << sources[num_entry]); }