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=-14.3 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 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 93A1FC432BE for ; Mon, 2 Aug 2021 02:47:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7DC6160F35 for ; Mon, 2 Aug 2021 02:47:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231928AbhHBCrm (ORCPT ); Sun, 1 Aug 2021 22:47:42 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49822 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229908AbhHBCrk (ORCPT ); Sun, 1 Aug 2021 22:47:40 -0400 Received: from mail-pl1-x634.google.com (mail-pl1-x634.google.com [IPv6:2607:f8b0:4864:20::634]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3BCC1C06175F; Sun, 1 Aug 2021 19:47:31 -0700 (PDT) Received: by mail-pl1-x634.google.com with SMTP id u16so9499493ple.2; Sun, 01 Aug 2021 19:47:31 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-transfer-encoding:content-language; bh=XGbL8VwPWjiS4yy4Pnm/5ti4pl6SnxB74geqfXf2DB8=; b=LT7iIak5S9eMVKEPZD7f0f9GaeTpf9fgxki9F73OG5+doNYssSWZ0f3lw9FdaLyodW H+VftdRCAibeNawcMs/+wyMV07jxOnbL2d85GMVLWLny7/IBriAfc+cOb+mHA6nW71Sx +5e9Xv+cfGX0tEiE7nHyJMElLi5Km8LSwGXHcZwBfY9cpcGfgAR2+q2AjdJQ1aNq95mA ewqlpUaBT5mu9mYGHzlsh+9ZPR9mbnKe/5Nn193sVNPYJMVvCowTFjQMzJcfWdZF/BM9 ebe+OlZy1qPrEgPHdxuZBs0OXp5M+PrN3KdfC165JaM+goeJQfUbsVmboOQDq396IF8R 8SPw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-transfer-encoding :content-language; bh=XGbL8VwPWjiS4yy4Pnm/5ti4pl6SnxB74geqfXf2DB8=; b=TXwiFGK+YyKKO0U1DeuAgDPrB9bWGyDr+dPnvN8PcKMI1tGtOySLbb/YW6dk8IgMzf Bbtaegf2xGLNSIeW2QLF5uZaEJxYSGxrZ6yfMF2ojVuecz5TXBUxrWo0cVDn2dZmcLTF q28b42rRRLRx1kaabWpwmgMDZOHZoDnZuZbsMPGiOA4L6nvgEzr10QgapKvZGuxApen4 8OI/gWYHOkJdQr+aLJ1puao9+++1JosH3fwMTu6brqE1MQ+/nN1L4bU9kfY7RQnnoPVJ igVkB8guRG3y+aA2THRASBu3iqoswxxFb61ysr0d8txb2ErJVn+nVM6/3s89YW7wi84E lmFA== X-Gm-Message-State: AOAM531XJp2AzXwBL3a5QhLPUAAXLSEO8y8Q5mtViayCcfITtF7RqHGd vuo/1KkB/TwhJZxG1f0qt94= X-Google-Smtp-Source: ABdhPJxgLjle+X21msmkhScpohfSjneeqWivm7M3aHQYJvRXfoBdbPMfQOdSLJPQMzM3M/tZB5hKow== X-Received: by 2002:a17:903:20c1:b029:12c:4a37:5cbb with SMTP id i1-20020a17090320c1b029012c4a375cbbmr12001050plb.57.1627872450825; Sun, 01 Aug 2021 19:47:30 -0700 (PDT) Received: from [10.106.0.86] ([45.135.186.29]) by smtp.gmail.com with ESMTPSA id l14sm9517229pfd.58.2021.08.01.19.47.26 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Sun, 01 Aug 2021 19:47:30 -0700 (PDT) Subject: Re: [PATCH] drm/amdgpu: fix possible null-pointer dereference in amdgpu_ttm_tt_populate() To: =?UTF-8?Q?Christian_K=c3=b6nig?= Cc: amd-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, airlied@linux.ie, linux-media@vger.kernel.org, linaro-mm-sig@lists.linaro.org, Xinhui.Pan@amd.com, baijiaju1990@gmail.com, alexander.deucher@amd.com, Philip.Yang@amd.com, TOTE Robot , sumit.semwal@linaro.org, daniel@ffwll.ch, Felix.Kuehling@amd.com, airlied@redhat.com, Oak.Zeng@amd.com, nirmoy.das@amd.com, tzimmermann@suse.de References: <20210731080437.74539-1-islituo@gmail.com> <53ef6ff7-f793-5de4-4ab4-0efbfbfc0a54@amd.com> From: Li Tuo Message-ID: Date: Mon, 2 Aug 2021 10:47:24 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.12.0 MIME-Version: 1.0 In-Reply-To: <53ef6ff7-f793-5de4-4ab4-0efbfbfc0a54@amd.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Content-Language: en-US Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Thanks for your feedback! We will remove the null tests according to your advice and prepare a V2 patch. Best wishes, Tuo Li On 2021/8/2 1:19, Christian König wrote: > Am 31.07.21 um 10:04 schrieb Tuo Li: >> The variable ttm is assigned to the variable gtt, and the variable gtt >> is checked in: >>    if (gtt && gtt->userptr) >> >> This indicates that both ttm and gtt can be NULL. >> If so, a null-pointer dereference will occur: >>    if (ttm->page_flags & TTM_PAGE_FLAG_SG) >> >> Also, some null-pointer dereferences will occur in the function >> ttm_pool_alloc() which is called in: >>    return ttm_pool_alloc(&adev->mman.bdev.pool, ttm, ctx); >> >> To fix these possible null-pointer dereferences, the function returns >> -EINVAL when ttm is NULL. > > NAK, the NULL test is just a leftover from when the objects where > distinct. > > Please remove the NULL test instead. > > Regards, > Christian. > >> >> Reported-by: TOTE Robot >> Signed-off-by: Tuo Li >> --- >>   drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c | 5 ++++- >>   1 file changed, 4 insertions(+), 1 deletion(-) >> >> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c >> b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c >> index 3a55f08e00e1..80440f799c09 100644 >> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c >> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c >> @@ -1120,8 +1120,11 @@ static int amdgpu_ttm_tt_populate(struct >> ttm_device *bdev, >>       struct amdgpu_device *adev = amdgpu_ttm_adev(bdev); >>       struct amdgpu_ttm_tt *gtt = (void *)ttm; >>   +    if (ttm == NULL) >> +        return -EINVAL; >> + >>       /* user pages are bound by amdgpu_ttm_tt_pin_userptr() */ >> -    if (gtt && gtt->userptr) { >> +    if (gtt->userptr) { >>           ttm->sg = kzalloc(sizeof(struct sg_table), GFP_KERNEL); >>           if (!ttm->sg) >>               return -ENOMEM; >