From nobody Mon May 11 04:52:12 2026 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 74ACFC433EF for ; Thu, 14 Apr 2022 06:14:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239988AbiDNGQt (ORCPT ); Thu, 14 Apr 2022 02:16:49 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43372 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229990AbiDNGQr (ORCPT ); Thu, 14 Apr 2022 02:16:47 -0400 Received: from mail-pj1-x1034.google.com (mail-pj1-x1034.google.com [IPv6:2607:f8b0:4864:20::1034]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 72A3D641C; Wed, 13 Apr 2022 23:14:21 -0700 (PDT) Received: by mail-pj1-x1034.google.com with SMTP id o5-20020a17090ad20500b001ca8a1dc47aso8404018pju.1; Wed, 13 Apr 2022 23:14:21 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=from:to:cc:subject:date:message-id; bh=xSaEo9LO7falECQjCcduKi//QmoNEw98a9U9ZQZJgh0=; b=kxTi7L39zBMmLwbO/yI0P60LXETiezuazG6rlO5ELFcbhEY1oEruR/u/1yo6N3KdQM 2O3AUj5NiRsJ7q8fAiWhsh1U7XzByWNXQ0o+0xTNY6Fm/VpR3V3BCHnj6q1Y4ZmerDhl ml3SH/gbEb8sBaGbfujS5u45t1wFcG08OKiubAk72kE3re/C0hcN5oRWV5yHx2cWPh3G 4EHxbAAxD5TeYvB/GTp04kn5Ko8AZzXvBXTj5w73Klbl6Pym2+BixMDk3gFHJN2VGOg0 7cDTVYIflbge4PL8N9KjNv+cRh+9M1Nx1gAYdPFS3eYVK5FrN+1+TYR4Yd2qMNOSfcC9 GKpw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id; bh=xSaEo9LO7falECQjCcduKi//QmoNEw98a9U9ZQZJgh0=; b=jFyJeWD+L8o7x8WNA8Suz4cYTeqA5QmdL5I21iZPv0cfuHuyGJ34A79moLVBfYnUO4 r5SP+/vPT7XWA6ZMHB7AhUDQ7ir8hIYBnRumZZDgWRmFwIhgkPy5VeUrAbdcR8A/WFdX puBbfMO/2htGL9tE/8y7LJuidENU4lGYDz/PrAkR0NUDcUfoX1P474OB7FGmWnuB465F JB6Rjd6nREMJrAN64XepmlEBl0oQY7TSMb6mU6Cq6E9aQZOhzQ7DEaAgdBjIfG6QBfcE xZuBCs1fpqMydD6FsHIM1EkpsTUYdGCu39ONlwWz2J84lPS5e+CLZ3pAgUG5H+/n5+ch 9liQ== X-Gm-Message-State: AOAM531e5vSTOXcH/JXpnb3rMqa6gnfaR6wsPJw6TzZ/aBUaocL7UfnG beycy9J4tyc9rmFLc55UejA= X-Google-Smtp-Source: ABdhPJzfqbuE+SKFgvlaHYYvwCo6iZQfPGv6i6/v9EAG/8WGUTum8VyjBgQWC5Y8dRWej4ZxlU0lQQ== X-Received: by 2002:a17:90a:ca:b0:1ca:5253:b625 with SMTP id v10-20020a17090a00ca00b001ca5253b625mr2065267pjd.220.1649916860983; Wed, 13 Apr 2022 23:14:20 -0700 (PDT) Received: from localhost.localdomain ([119.3.119.18]) by smtp.gmail.com with ESMTPSA id 25-20020a631259000000b0039d353e6d75sm927364pgs.57.2022.04.13.23.14.17 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 13 Apr 2022 23:14:20 -0700 (PDT) From: Xiaomeng Tong To: tomba@kernel.org, airlied@linux.ie, daniel@ffwll.ch Cc: dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, Xiaomeng Tong , stable@vger.kernel.org Subject: [RESEND][PATCH] omapdrm: fix missing check on list iterator Date: Thu, 14 Apr 2022 14:14:10 +0800 Message-Id: <20220414061410.7678-1-xiam0nd.tong@gmail.com> X-Mailer: git-send-email 2.17.1 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" The bug is here: bus_flags =3D connector->display_info.bus_flags; The list iterator 'connector-' will point to a bogus position containing HEAD if the list is empty or no element is found. This case must be checked before any use of the iterator, otherwise it will lead to a invalid memory access. To fix this bug, add an check. Use a new value 'iter' as the list iterator, while use the old value 'connector' as a dedicated variable to point to the found element. Cc: stable@vger.kernel.org Fixes: ("drm/omap: Add support for drm_panel") Signed-off-by: Xiaomeng Tong --- drivers/gpu/drm/omapdrm/omap_encoder.c | 14 +++++++++----- 1 file changed, 9 insertions(+), 5 deletions(-) diff --git a/drivers/gpu/drm/omapdrm/omap_encoder.c b/drivers/gpu/drm/omapd= rm/omap_encoder.c index 4dd05bc732da..d648ab4223b1 100644 --- a/drivers/gpu/drm/omapdrm/omap_encoder.c +++ b/drivers/gpu/drm/omapdrm/omap_encoder.c @@ -76,14 +76,16 @@ static void omap_encoder_mode_set(struct drm_encoder *e= ncoder, struct omap_encoder *omap_encoder =3D to_omap_encoder(encoder); struct omap_dss_device *output =3D omap_encoder->output; struct drm_device *dev =3D encoder->dev; - struct drm_connector *connector; + struct drm_connector *connector =3D NULL, *iter; struct drm_bridge *bridge; struct videomode vm =3D { 0 }; u32 bus_flags; =20 - list_for_each_entry(connector, &dev->mode_config.connector_list, head) { - if (connector->encoder =3D=3D encoder) + list_for_each_entry(iter, &dev->mode_config.connector_list, head) { + if (iter->encoder =3D=3D encoder) { + connector =3D iter; break; + } } =20 drm_display_mode_to_videomode(adjusted_mode, &vm); @@ -106,8 +108,10 @@ static void omap_encoder_mode_set(struct drm_encoder *= encoder, omap_encoder_update_videomode_flags(&vm, bus_flags); } =20 - bus_flags =3D connector->display_info.bus_flags; - omap_encoder_update_videomode_flags(&vm, bus_flags); + if (connector) { + bus_flags =3D connector->display_info.bus_flags; + omap_encoder_update_videomode_flags(&vm, bus_flags); + } =20 /* Set timings for all devices in the display pipeline. */ dss_mgr_set_timings(output, &vm); --=20 2.17.1