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 X-Spam-Level: X-Spam-Status: No, score=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1BD94C433E0 for ; Thu, 11 Mar 2021 13:11:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C68B964FE0 for ; Thu, 11 Mar 2021 13:11:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233448AbhCKNKh (ORCPT ); Thu, 11 Mar 2021 08:10:37 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42438 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233465AbhCKNKU (ORCPT ); Thu, 11 Mar 2021 08:10:20 -0500 Received: from mail-wm1-x336.google.com (mail-wm1-x336.google.com [IPv6:2a00:1450:4864:20::336]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 08A5AC061760 for ; Thu, 11 Mar 2021 05:10:20 -0800 (PST) Received: by mail-wm1-x336.google.com with SMTP id b2-20020a7bc2420000b029010be1081172so12761799wmj.1 for ; Thu, 11 Mar 2021 05:10:19 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ffwll.ch; s=google; h=date:from:to:cc:subject:message-id:mail-followup-to:references :mime-version:content-disposition:content-transfer-encoding :in-reply-to; bh=+hhpCW4NXZ2+Io3IMxIPYt+lYnp9sm+v1Ci9SUk4a3o=; b=JNpInhzYi/QnLCeOhXJx5y7ODz0WDyvNCzDUaEHpOk3MmBIeniVihqSRcfAx5GJ7px Jr+zQJ+o5Qlg1Vhf6G4z1e+jH7desHi3Dbn82MxKmS1Nq+qSx+mmW4AVXBigDJ/G0YuZ pGbslCB6D3BwYRFru3GF5x9gCIm9fC2/1MXxU= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id :mail-followup-to:references:mime-version:content-disposition :content-transfer-encoding:in-reply-to; bh=+hhpCW4NXZ2+Io3IMxIPYt+lYnp9sm+v1Ci9SUk4a3o=; b=uSw9u6m4vEFRbU+FtUUZahOksS7KlWCyIgDor55VD5owgFxxhacSC9uTd7eIsOGJ+6 rWIKyrZGmhp4xgvVBAklYu9ByG+CGOpojBpudlbPk+2To/sLcVA5pGiGIdxPydGHZ7yO 1vyQYOTm9ndL9Z3pXTUogtjoazn5x65iMo3AWcTakMECD6UucWbUmQnCh8iac50Bbkt1 MxreHrPo3IkIv7k+cabEf5JDtCVdMRVyMXXVX4aUO9lbhs7tX7ORfgNrTP33barSUBNy v7YgRsQYIGQziwAtr9VM+ra16cw1Mg7wGIbJqIKdRpmFncZsroPmC2W4BoEU5M5eRcWw xbbQ== X-Gm-Message-State: AOAM533qbLGeTvxAbeeL6PJ0+DKc9wLQG0ttXlgkD152iZvV752+QU2Q oJGOCv5HCF2IEl7pJKaUFrGtbg== X-Google-Smtp-Source: ABdhPJy51Lb+MAwQ+byf24AEh2DP5jP8rj5VHu5rcUu4pEdw0ULIAaT7cZjaXYbs9Ol1mcprLfnklA== X-Received: by 2002:a1c:7e45:: with SMTP id z66mr8189532wmc.126.1615468218741; Thu, 11 Mar 2021 05:10:18 -0800 (PST) Received: from phenom.ffwll.local ([2a02:168:57f4:0:efd0:b9e5:5ae6:c2fa]) by smtp.gmail.com with ESMTPSA id g5sm3782504wrq.30.2021.03.11.05.10.17 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 11 Mar 2021 05:10:18 -0800 (PST) Date: Thu, 11 Mar 2021 14:10:16 +0100 From: Daniel Vetter To: Christian =?iso-8859-1?Q?K=F6nig?= Cc: Colin King , Alex Deucher , David Airlie , Daniel Vetter , Marek =?utf-8?B?T2zFocOhaw==?= , amd-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, kernel-janitors@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] drm/radeon: fix copy of uninitialized variable back to userspace Message-ID: Mail-Followup-To: Christian =?iso-8859-1?Q?K=F6nig?= , Colin King , Alex Deucher , David Airlie , Marek =?utf-8?B?T2zFocOhaw==?= , amd-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, kernel-janitors@vger.kernel.org, linux-kernel@vger.kernel.org References: <20210303002759.28752-1-colin.king@canonical.com> <490409f2-9fcb-d402-a6ae-b45c80bae3d2@amd.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <490409f2-9fcb-d402-a6ae-b45c80bae3d2@amd.com> X-Operating-System: Linux phenom 5.7.0-1-amd64 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Mar 03, 2021 at 08:42:31AM +0100, Christian König wrote: > Am 03.03.21 um 01:27 schrieb Colin King: > > From: Colin Ian King > > > > Currently the ioctl command RADEON_INFO_SI_BACKEND_ENABLED_MASK can > > copy back uninitialised data in value_tmp that pointer *value points > > to. This can occur when rdev->family is less than CHIP_BONAIRE and > > less than CHIP_TAHITI. Fix this by adding in a missing -EINVAL > > so that no invalid value is copied back to userspace. > > > > Addresses-Coverity: ("Uninitialized scalar variable) > > Cc: stable@vger.kernel.org # 3.13+ > > Fixes: 439a1cfffe2c ("drm/radeon: expose render backend mask to the userspace") > > Signed-off-by: Colin Ian King > > Reviewed-by: Christian König > > Let's hope that this doesn't break UAPI. If it does I think the only difference would be errno userspace sees (aside from the stack garbage, which we could also emulate). Switching to return 0; is easy. So no worries this would be a problem :-) -Daniel > > Christian. > > > --- > > drivers/gpu/drm/radeon/radeon_kms.c | 1 + > > 1 file changed, 1 insertion(+) > > > > diff --git a/drivers/gpu/drm/radeon/radeon_kms.c b/drivers/gpu/drm/radeon/radeon_kms.c > > index 2479d6ab7a36..58876bb4ef2a 100644 > > --- a/drivers/gpu/drm/radeon/radeon_kms.c > > +++ b/drivers/gpu/drm/radeon/radeon_kms.c > > @@ -518,6 +518,7 @@ int radeon_info_ioctl(struct drm_device *dev, void *data, struct drm_file *filp) > > *value = rdev->config.si.backend_enable_mask; > > } else { > > DRM_DEBUG_KMS("BACKEND_ENABLED_MASK is si+ only!\n"); > > + return -EINVAL; > > } > > break; > > case RADEON_INFO_MAX_SCLK: > -- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch