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=-19.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,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 2965CC433B4 for ; Mon, 12 Apr 2021 16:24:31 +0000 (UTC) Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id E99D3611AD for ; Mon, 12 Apr 2021 16:24:30 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E99D3611AD Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=xen-devel-bounces@lists.xenproject.org Received: from list by lists.xenproject.org with outflank-mailman.109371.208790 (Exim 4.92) (envelope-from ) id 1lVzMM-0004Pt-5T; Mon, 12 Apr 2021 16:24:22 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 109371.208790; Mon, 12 Apr 2021 16:24:22 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1lVzMM-0004Pm-2X; Mon, 12 Apr 2021 16:24:22 +0000 Received: by outflank-mailman (input) for mailman id 109371; Mon, 12 Apr 2021 16:24:20 +0000 Received: from us1-rack-iad1.inumbo.com ([172.99.69.81]) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1lVzMK-0004Pe-Ii for xen-devel@lists.xenproject.org; Mon, 12 Apr 2021 16:24:20 +0000 Received: from mail.kernel.org (unknown [198.145.29.99]) by us1-rack-iad1.inumbo.com (Halon) with ESMTPS id f49a0939-51e5-4899-b89a-2ac2edfc5232; Mon, 12 Apr 2021 16:24:20 +0000 (UTC) Received: by mail.kernel.org (Postfix) with ESMTPSA id ACE4C6136C; Mon, 12 Apr 2021 16:24:18 +0000 (UTC) X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" X-Inumbo-ID: f49a0939-51e5-4899-b89a-2ac2edfc5232 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1618244659; bh=KgQAhTj6sUm8dp2+WQQSK3nP7Y2J/NZ4Vx5xWPL84os=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=WAZ2k0TGS7fcDzgO/l5cyt1+kbKIy3KOprSX+Oof1qwOrQCqJn43qurWJL572xnrK d82uakrXnbB80Jy76TzMAjVnhqPE7BRhwIGGFCfAFQS7Nq2juLriWg8PGlo5cEFTIZ KV8v4Km5NOb05qGIXSRPuRMsKkw6h1cq7x0l1+YHlTs78GS+1EgsHoHpDxWDxO5rBI S1u+a8NWXYIpag04iTlSOAB9XQErsgbvGyiTEl/Z55EAYkcy6ZXjeUH5UQ2hesV6ur 7zUSKR0ZWJ18lliDhKkftbu+HqySGyAKqwa1jXjESPPuif6M3pzaP/dBBaPDuAoGAC /NZlAew11qndQ== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Lv Yunlong , Oleksandr Andrushchenko , Sasha Levin , dri-devel@lists.freedesktop.org, xen-devel@lists.xenproject.org Subject: [PATCH AUTOSEL 5.10 14/46] gpu/xen: Fix a use after free in xen_drm_drv_init Date: Mon, 12 Apr 2021 12:23:29 -0400 Message-Id: <20210412162401.314035-14-sashal@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210412162401.314035-1-sashal@kernel.org> References: <20210412162401.314035-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit From: Lv Yunlong [ Upstream commit 52762efa2b256ed1c5274e5177cbd52ee11a2f6a ] In function displback_changed, has the call chain displback_connect(front_info)->xen_drm_drv_init(front_info). We can see that drm_info is assigned to front_info->drm_info and drm_info is freed in fail branch in xen_drm_drv_init(). Later displback_disconnect(front_info) is called and it calls xen_drm_drv_fini(front_info) cause a use after free by drm_info = front_info->drm_info statement. My patch has done two things. First fixes the fail label which drm_info = kzalloc() failed and still free the drm_info. Second sets front_info->drm_info to NULL to avoid uaf. Signed-off-by: Lv Yunlong Reviewed-by: Oleksandr Andrushchenko Signed-off-by: Oleksandr Andrushchenko Link: https://patchwork.freedesktop.org/patch/msgid/20210323014656.10068-1-lyl2019@mail.ustc.edu.cn Signed-off-by: Sasha Levin --- drivers/gpu/drm/xen/xen_drm_front.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/xen/xen_drm_front.c b/drivers/gpu/drm/xen/xen_drm_front.c index cc93a8c9547b..8ea91542b567 100644 --- a/drivers/gpu/drm/xen/xen_drm_front.c +++ b/drivers/gpu/drm/xen/xen_drm_front.c @@ -531,7 +531,7 @@ static int xen_drm_drv_init(struct xen_drm_front_info *front_info) drm_dev = drm_dev_alloc(&xen_drm_driver, dev); if (IS_ERR(drm_dev)) { ret = PTR_ERR(drm_dev); - goto fail; + goto fail_dev; } drm_info->drm_dev = drm_dev; @@ -561,8 +561,10 @@ static int xen_drm_drv_init(struct xen_drm_front_info *front_info) drm_kms_helper_poll_fini(drm_dev); drm_mode_config_cleanup(drm_dev); drm_dev_put(drm_dev); -fail: +fail_dev: kfree(drm_info); + front_info->drm_info = NULL; +fail: return ret; } -- 2.30.2