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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,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 F0BC6C43603 for ; Tue, 10 Dec 2019 21:39:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B9FBF2073B for ; Tue, 10 Dec 2019 21:39:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1576013961; bh=b/KjiDjETamHW9Y/8FNozm/dGxjife84uORnLJ/QAO0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=bEpDT2OFldBavN50IpDN3eN6IvTLnNI6pjsDledcu8giKtaEd1MpP5AcodVTp0YbD DeSjUtSy/GTIrjI7BQ4w7Q1MGtfq+dz23CEnDxcTUc4ezo7O8V7qMKyXBm8IxxjIrX aWigpXPs/4jpBeDs4Q64gOoF3PnItKXVsI2wS/5Y= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730150AbfLJVe6 (ORCPT ); Tue, 10 Dec 2019 16:34:58 -0500 Received: from mail.kernel.org ([198.145.29.99]:40142 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730094AbfLJVer (ORCPT ); Tue, 10 Dec 2019 16:34:47 -0500 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id D8B91207FF; Tue, 10 Dec 2019 21:34:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1576013686; bh=b/KjiDjETamHW9Y/8FNozm/dGxjife84uORnLJ/QAO0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=u405EaP1BZTq8noYYF8BaS8zTwV42211rlTiRHlfmyEt2mUf8xd4eWv+y+w/Cf3hd CRDqY441KJpIMNd4WLzpBIwtmBliv61QDz9a0V1OxFS7eEm6IVhr6jQKGUCWtyQAl8 mH9zNFSRfZs0xfcS8KGdVC/C6Q9yPMIzVMhoVc1c= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Pan Bian , =?UTF-8?q?Christian=20K=C3=B6nig?= , Alex Deucher , Sasha Levin , amd-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org Subject: [PATCH AUTOSEL 4.19 119/177] drm/amdgpu: fix potential double drop fence reference Date: Tue, 10 Dec 2019 16:31:23 -0500 Message-Id: <20191210213221.11921-119-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20191210213221.11921-1-sashal@kernel.org> References: <20191210213221.11921-1-sashal@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Pan Bian [ Upstream commit 946ab8db6953535a3a88c957db8328beacdfed9d ] The object fence is not set to NULL after its reference is dropped. As a result, its reference may be dropped again if error occurs after that, which may lead to a use after free bug. To avoid the issue, fence is explicitly set to NULL after dropping its reference. Acked-by: Christian König Signed-off-by: Pan Bian Signed-off-by: Alex Deucher Signed-off-by: Sasha Levin --- drivers/gpu/drm/amd/amdgpu/amdgpu_test.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_test.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_test.c index 8904e62dca7ae..41d3142ef3cf0 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_test.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_test.c @@ -138,6 +138,7 @@ static void amdgpu_do_test_moves(struct amdgpu_device *adev) } dma_fence_put(fence); + fence = NULL; r = amdgpu_bo_kmap(vram_obj, &vram_map); if (r) { @@ -183,6 +184,7 @@ static void amdgpu_do_test_moves(struct amdgpu_device *adev) } dma_fence_put(fence); + fence = NULL; r = amdgpu_bo_kmap(gtt_obj[i], >t_map); if (r) { -- 2.20.1