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 98259C2D0BF for ; Tue, 10 Dec 2019 22:05:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 63E2A24656 for ; Tue, 10 Dec 2019 22:05:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1576015503; bh=E7/z7BY6qXc1wYTIEv4/qpE9spSJTtJDiNWaAiITXq0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=aK2kHq9edqY78yoSz0rb0baNjAAe14XEiLVSPUXWOo8NHPktqnRBjDTHsTwcWJ646 rIx9KKvH3kKNarte4668fI0QRCLwYnG/IeYW4HeAbFmetwmxXBsBSr29a/DZztzVu6 XXBawizFyb+StFKrO3vAv8tx3C7b6eLN/dDmEFfs= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729336AbfLJWFC (ORCPT ); Tue, 10 Dec 2019 17:05:02 -0500 Received: from mail.kernel.org ([198.145.29.99]:35774 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729152AbfLJWEs (ORCPT ); Tue, 10 Dec 2019 17:04:48 -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 A4FFB214D8; Tue, 10 Dec 2019 22:04:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1576015487; bh=E7/z7BY6qXc1wYTIEv4/qpE9spSJTtJDiNWaAiITXq0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=aBdq1XBk2fSS6QwpCQHIy/CAsde7X9KGDh41rOrzsSNck9/eJE8TgFHYdcnw/SXyU Tf6+wH28ObCUMM0oUdVGKY/yhjSFap0BJWNuw8Gj28bMdaXQ4r6nXHBy5s96AxDUpT 8K6j+nSXR7FzqOkzgDpcTPePncKy+PS8Fzljs0Pc= 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 4.14 090/130] drm/amdgpu: fix potential double drop fence reference Date: Tue, 10 Dec 2019 17:02:21 -0500 Message-Id: <20191210220301.13262-90-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20191210220301.13262-1-sashal@kernel.org> References: <20191210220301.13262-1-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 ed8c3739015be..b35b0741fd97e 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_test.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_test.c @@ -125,6 +125,7 @@ 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) { @@ -170,6 +171,7 @@ 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