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=-15.7 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,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 7541FC4338F for ; Sat, 31 Jul 2021 08:13:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5E1EB60F94 for ; Sat, 31 Jul 2021 08:13:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232622AbhGaINh (ORCPT ); Sat, 31 Jul 2021 04:13:37 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47232 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230338AbhGaINe (ORCPT ); Sat, 31 Jul 2021 04:13:34 -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 4CB19C06175F; Sat, 31 Jul 2021 01:13:28 -0700 (PDT) Received: by mail-pl1-x634.google.com with SMTP id t3so11731463plg.9; Sat, 31 Jul 2021 01:13:28 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=pSqWDBwjSHpo0CpUmYzJgqTp6C8xaprSXoTH68RUk9A=; b=uByXvFJLrQigPJrd54cWKzjfeHhmv/59d2ORQVsOva+5sc8NUkvICieZBg18ItO2Bl H+jyxMqxtR0naDcAwKzLvkcaHmdzHLlTRV2Qd5tSi0sHOfJJSg7jY/ebFfZeOmmti3qi 1vVVuxwkQwYobrzkHkFpnjjzAjyaH6FXU2fi77dkQQkKugCrqjK1T9MFCse+PXzQRtIY XP0TZajX/Rxe7SI2zQ5gYjE3+38td6o/gj0n5cl9efRbBGYGQYjXqzIiEadVQx9HQlGx ta+9+0HadNRRG8JvzJnzj1NnY2ljjQUf+MbJ1vsR007GS4MkFmVY6+qUL3xODTt8ppuZ CEMw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=pSqWDBwjSHpo0CpUmYzJgqTp6C8xaprSXoTH68RUk9A=; b=STnuAzggIMj5UrjyYlZ1U99BvLdaKf9JGUJjJINNIpX9V9+IrmX+JeDwRajezaNLm2 F9dF6VrAyDrqRbtisLEgWV90ZaDhmd5tsS4IQWaq9Q3cAmsZMUvPoEamMAH0fzFtQiAy yqR4Ec2gmHpUTvArVtnHQr1iP6ngsdHXdcSP+fNX/QHynTocRugN5nPkEFUJG53sVml2 e1JgcDIvebXjFQh1ac3kgBv8CMI3uPArlqtBQUt3cdbEh4G4BXmQakWnKJ1LdkWqPve5 xTzHrnHhCqAbMYrV0W2+/MD3cPVC7cYFndFNHbVJaw1hc+jvlnSbMDR9OE6HpKXmZLu3 GNKQ== X-Gm-Message-State: AOAM531W/XkuHX44ZXHZx6oQazFRqr4nlVaBK8W3cirYk4CGsRqsxwUn /Wk3iMHeJDo/WQ/ZrV1tWwc= X-Google-Smtp-Source: ABdhPJw3sUv7SWXCtHAKD2+0aZD/9TU7DS9fJq1J3MW2qhUDFcv1S/rMnj/DfvR5PrG6iihq7vzA3Q== X-Received: by 2002:a62:30c5:0:b029:31e:fa6d:1738 with SMTP id w188-20020a6230c50000b029031efa6d1738mr6786010pfw.55.1627719207841; Sat, 31 Jul 2021 01:13:27 -0700 (PDT) Received: from localhost.localdomain ([45.135.186.29]) by smtp.gmail.com with ESMTPSA id c7sm5314475pgq.22.2021.07.31.01.13.23 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 31 Jul 2021 01:13:27 -0700 (PDT) From: Tuo Li To: alexander.deucher@amd.com, christian.koenig@amd.com, Xinhui.Pan@amd.com, airlied@linux.ie, daniel@ffwll.ch, sumit.semwal@linaro.org, airlied@redhat.com, Felix.Kuehling@amd.com, Oak.Zeng@amd.com, nirmoy.das@amd.com, tzimmermann@suse.de, Philip.Yang@amd.com Cc: amd-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, linux-media@vger.kernel.org, linaro-mm-sig@lists.linaro.org, baijiaju1990@gmail.com, Tuo Li , TOTE Robot Subject: [PATCH] drm/amdgpu: fix possible null-pointer dereference in amdgpu_ttm_tt_unpopulate() Date: Sat, 31 Jul 2021 01:13:06 -0700 Message-Id: <20210731081306.86523-1-islituo@gmail.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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_free() which is called in: return ttm_pool_free(&adev->mman.bdev.pool, ttm); To fix these possible null-pointer dereferences, the function returns when ttm is NULL. 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..0216ca085f11 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c @@ -1146,7 +1146,10 @@ static void amdgpu_ttm_tt_unpopulate(struct ttm_device *bdev, struct amdgpu_ttm_tt *gtt = (void *)ttm; struct amdgpu_device *adev; - if (gtt && gtt->userptr) { + if (ttm == NULL) + return; + + if (gtt->userptr) { amdgpu_ttm_tt_set_user_pages(ttm, NULL); kfree(ttm->sg); ttm->sg = NULL; -- 2.25.1