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=-9.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham 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 C6A42C5DF62 for ; Wed, 6 Nov 2019 09:15:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9251A217F5 for ; Wed, 6 Nov 2019 09:15:14 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=163.com header.i=@163.com header.b="LuKoXVvY" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731613AbfKFJPN (ORCPT ); Wed, 6 Nov 2019 04:15:13 -0500 Received: from mail-m972.mail.163.com ([123.126.97.2]:40242 "EHLO mail-m972.mail.163.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726755AbfKFJPN (ORCPT ); Wed, 6 Nov 2019 04:15:13 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=163.com; s=s110527; h=From:Subject:Date:Message-Id; bh=sVdTflIE+iXOvcN6Wo Co4qaadEnEkJvxlkUvIsF0664=; b=LuKoXVvYBTHDB35390tz/PmzS63L14Czxp YffOwccsl12O3nTXjjBNyxg1uUOghBPiyU4jOs/3x/3/eAfI/4nsDVEg8E85ko55 Uxigc19ZUFHZy0yBILc9qstlxkVmXQTLDCnia55Ax4zKX4UO8m0mFrWuqim1tRWe zxuTErRKQ= Received: from localhost.localdomain (unknown [202.112.113.212]) by smtp2 (Coremail) with SMTP id GtxpCgCXOxEGj8Jd3sZmBA--.31S3; Wed, 06 Nov 2019 17:14:48 +0800 (CST) From: Pan Bian To: Alex Deucher , christian.koenig@amd.com, "David (ChunMing) Zhou" , David Airlie , Daniel Vetter , Sam Ravnborg Cc: amd-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, Pan Bian Subject: [PATCH] drm/amdgpu: fix potential double drop fence reference Date: Wed, 6 Nov 2019 17:14:45 +0800 Message-Id: <1573031685-25969-1-git-send-email-bianpan2016@163.com> X-Mailer: git-send-email 2.7.4 X-CM-TRANSID: GtxpCgCXOxEGj8Jd3sZmBA--.31S3 X-Coremail-Antispam: 1Uf129KBjvdXoW7JFWfKF1xur1kCrW8Zr47urg_yoWDCwb_uF WUXFn3Cw13CFn0gF17Zr45Za9rt345Za1kWr1ft39YyryUZ3yjq34Uurn5Xa18uayxWasr X3WqgFyYkwnrCjkaLaAFLSUrUUUUUb8apTn2vfkv8UJUUUU8Yxn0WfASr-VFAUDa7-sFnT 9fnUUvcSsGvfC2KfnxnUUI43ZEXa7IUjXdb7UUUUU== X-Originating-IP: [202.112.113.212] X-CM-SenderInfo: held01tdqsiiqw6rljoofrz/1tbiQAhlclSIdIDGYwAAsS Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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. Signed-off-by: Pan Bian --- 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 b66d29d5ffa2..b158230af8db 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) { -- 2.7.4