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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id EEED8C4332F for ; Tue, 22 Nov 2022 09:12:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233268AbiKVJMZ (ORCPT ); Tue, 22 Nov 2022 04:12:25 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45450 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233266AbiKVJMN (ORCPT ); Tue, 22 Nov 2022 04:12:13 -0500 Received: from madras.collabora.co.uk (madras.collabora.co.uk [46.235.227.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CE02747329 for ; Tue, 22 Nov 2022 01:12:11 -0800 (PST) Received: from [192.168.1.100] (2-237-20-237.ip236.fastwebnet.it [2.237.20.237]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) (Authenticated sender: kholk11) by madras.collabora.co.uk (Postfix) with ESMTPSA id E202B6602AC7; Tue, 22 Nov 2022 09:12:09 +0000 (GMT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=collabora.com; s=mail; t=1669108330; bh=XQs9y9qnM68EyMoHPrxiDgq88Oc9TnrG2mdHxwEI2sQ=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=CVkZzf1bm1eq3dnFoEDL8E2t9w+rllcHe6eClLcXsHRs+VHN3hKPjLV5NNgxlWMET eCx0667iQP4uhsgDs0Ept2jcZ+WRzK2yvZ+iscJPNmW3/3ygNLS+BSQh90MtVLdVD/ MWNJoQHV0S4QC2P5aJ+ftzSDFA4sDFr9UU6JgqR+1Qse4U7PDJb3mdOK0v1Ea5O1oX dYDT2WE7ySmP1NVyuln3YcUSAec7mQqv7o+88+519dSNMboAtN0GUhGifNWE0UzpW4 Y4O/McoElEA37GpxO7TJ9v+kFSWtsRDMXUk/tTthX6tDSzp7UWo/Uz+SgOZx2FgzhS /s9t1wFc4bXNg== Message-ID: <1ff98f52-93e1-d375-47ae-30b74068ea5b@collabora.com> Date: Tue, 22 Nov 2022 10:12:07 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.5.0 Subject: Re: [PATCH] drm/mediatek: Clean dangling pointer on bind error path To: =?UTF-8?B?TsOtY29sYXMgRi4gUi4gQS4gUHJhZG8=?= , Chun-Kuang Hu Cc: kernel@collabora.com, "Nancy . Lin" , Daniel Vetter , David Airlie , Matthias Brugger , Philipp Zabel , dri-devel@lists.freedesktop.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-mediatek@lists.infradead.org References: <20221121223717.3429913-1-nfraprado@collabora.com> Content-Language: en-US From: AngeloGioacchino Del Regno In-Reply-To: <20221121223717.3429913-1-nfraprado@collabora.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Il 21/11/22 23:37, Nícolas F. R. A. Prado ha scritto: > mtk_drm_bind() can fail, in which case drm_dev_put() is called, > destroying the drm_device object. However a pointer to it was still > being held in the private object, and that pointer would be passed along > to DRM in mtk_drm_sys_prepare() if a suspend were triggered at that > point, resulting in a panic. Clean the pointer when destroying the > object in the error path to prevent this from happening. > > Signed-off-by: Nícolas F. R. A. Prado > Fixes tag please! :-) Cheers, Angelo > --- > > drivers/gpu/drm/mediatek/mtk_drm_drv.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/drivers/gpu/drm/mediatek/mtk_drm_drv.c b/drivers/gpu/drm/mediatek/mtk_drm_drv.c > index 39a42dc8fb85..a21ff1b3258c 100644 > --- a/drivers/gpu/drm/mediatek/mtk_drm_drv.c > +++ b/drivers/gpu/drm/mediatek/mtk_drm_drv.c > @@ -514,6 +514,7 @@ static int mtk_drm_bind(struct device *dev) > err_deinit: > mtk_drm_kms_deinit(drm); > err_free: > + private->drm = NULL; > drm_dev_put(drm); > return ret; > }