From mboxrd@z Thu Jan 1 00:00:00 1970 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 7D0C4C4167B for ; Tue, 28 Nov 2023 12:54:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:Message-ID:Date:References :In-Reply-To:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=Q5iXGrBDqxi7m6+zKG7xGWGRo84LTc2C2yVQtifIYtE=; b=HQww4b3YuE0MLv gDYZx2+2KhR4O0pP817uEZKhwzB9E3N7Ww/QUqJXD6Fi5E6NL6xHZGVXYGyaTmBhfov95rTbIrQSY YwVoIMix3teZiiWACR+nLv1Y0gxnBCDJXTs7A/QJcIP3BWVFOoFYlE9IMFPExWFH61iP/qTDpP7Qx RUiP95bB51nzZXt5FiZWA0TFlfrzaYaXHKuHc9x2shvgK2RYMzxPs4EFLuL7ZOaUhJschjdvzH/hY gzyPRBnC7YkFqXzC7Nu8Lnuqv1H0rvSMQJBlnurdVs9obGIFgoWYNCSZxoqZzdklc24HfUL2YujSp herSuFyD9hbMxp+KR96g==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1r7xbT-005KTW-1t; Tue, 28 Nov 2023 12:54:15 +0000 Received: from mgamail.intel.com ([134.134.136.126]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1r7xbQ-005KSX-2O; Tue, 28 Nov 2023 12:54:14 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1701176052; x=1732712052; h=from:to:cc:subject:in-reply-to:references:date: message-id:mime-version; bh=5K++CR/OvistPw0XQfzY/YBgYQVr3P4OlOvmEu/zZC4=; b=aEe0FMCtLZoz4MH4M6tegdBa+9olVCNmCpgZPmklNmKA2BV0mQ1syNGV zmSOGmrCpBm9cbdYNZBZy4fOvghm+L1shexN3gFfLQoqFAcdG2H/ntSgN HE2YivSdU+aP80ithrrrjE7CQg54QFnN640bAsQKE5vtk+ueuJT5cp1Lv rY8rMLFJk5a0SDdf52DmzjgLx/5d6INnyU++6IcU9sSqqwJbwEYW3SpLA P9on7/wxTHTe99dzGuSbAoghdBGgRFKj/EgjtoEeyo15kYUvPM/X20sZ3 FFIGWq6Hfw/qZ0B3AELT8a9/1UCTvhVCe8JCUezYYj0VzPGKWUuMbD1SC g==; X-IronPort-AV: E=McAfee;i="6600,9927,10907"; a="377943912" X-IronPort-AV: E=Sophos;i="6.04,233,1695711600"; d="scan'208";a="377943912" Received: from fmsmga006.fm.intel.com ([10.253.24.20]) by orsmga106.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 28 Nov 2023 04:54:10 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10907"; a="1015900733" X-IronPort-AV: E=Sophos;i="6.04,233,1695711600"; d="scan'208";a="1015900733" Received: from mravivx-mobl.ger.corp.intel.com (HELO localhost) ([10.252.42.57]) by fmsmga006-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 28 Nov 2023 04:54:04 -0800 From: Jani Nikula To: Maxime Ripard , Maarten Lankhorst , Thomas Zimmermann , David Airlie , Daniel Vetter , Emma Anholt , Jonathan Corbet , Sandy Huang , Heiko =?utf-8?Q?St?= =?utf-8?Q?=C3=BCbner?= , Chen-Yu Tsai , Jernej Skrabec , Samuel Holland Cc: Hans Verkuil , dri-devel@lists.freedesktop.org, linux-arm-kernel@lists.infradead.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-media@vger.kernel.org, linux-rockchip@lists.infradead.org, linux-sunxi@lists.linux.dev, Maxime Ripard Subject: Re: [PATCH v4 05/45] drm/connector: Check drm_connector_init pointers arguments In-Reply-To: <20231128-kms-hdmi-connector-state-v4-5-c7602158306e@kernel.org> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo References: <20231128-kms-hdmi-connector-state-v4-0-c7602158306e@kernel.org> <20231128-kms-hdmi-connector-state-v4-5-c7602158306e@kernel.org> Date: Tue, 28 Nov 2023 14:54:02 +0200 Message-ID: <87h6l66nth.fsf@intel.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20231128_045412_839651_B95D380E X-CRM114-Status: GOOD ( 18.49 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Tue, 28 Nov 2023, Maxime Ripard wrote: > All the drm_connector_init variants take at least a pointer to the > device, connector and hooks implementation. > > However, none of them check their value before dereferencing those > pointers which can lead to a NULL-pointer dereference if the author > isn't careful. Arguably oopsing on the spot is preferrable when this can't be caused by user input. It's always a mistake that should be caught early during development. Not everyone checks the return value of drm_connector_init and friends, so those cases will lead to more mysterious bugs later. And probably oopses as well. BR, Jani. > > Let's test those pointers instead and error out if any is NULL. > > Signed-off-by: Maxime Ripard > --- > drivers/gpu/drm/drm_connector.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/drivers/gpu/drm/drm_connector.c b/drivers/gpu/drm/drm_connector.c > index b0516505f7ae..2f60755dccdd 100644 > --- a/drivers/gpu/drm/drm_connector.c > +++ b/drivers/gpu/drm/drm_connector.c > @@ -229,6 +229,9 @@ static int __drm_connector_init(struct drm_device *dev, > struct ida *connector_ida = > &drm_connector_enum_list[connector_type].ida; > > + if (!dev || !connector || !funcs) > + return -EINVAL; > + > WARN_ON(drm_drv_uses_atomic_modeset(dev) && > (!funcs->atomic_destroy_state || > !funcs->atomic_duplicate_state)); -- Jani Nikula, Intel _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel