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,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 16E4AC433DF for ; Tue, 9 Jun 2020 00:32:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DD69C2072F for ; Tue, 9 Jun 2020 00:32:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1591662735; bh=RIaJwXAv2CIPY/0FDHuz4E1BrCH0mzjtH5iCXkOJkoI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=KC7FX5NbQVR6LVOCbPTg8NTv9j2+RhxKogotRCrmuiVwqBSX+CTbPOiRQlt1UbyGp Bem9OTT57RzXO+0flA6RpxuCCt1/EKSTUnST6/8Z6BfnMZean/+/N3JyH2kYJ5k88k uyQiQ7RzS5aKY07De7GjrJNLvS8LtvaHYd1QdNpw= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730298AbgFIAcN (ORCPT ); Mon, 8 Jun 2020 20:32:13 -0400 Received: from mail.kernel.org ([198.145.29.99]:36160 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728805AbgFHXPR (ORCPT ); Mon, 8 Jun 2020 19:15:17 -0400 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 C7D742068D; Mon, 8 Jun 2020 23:15:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1591658117; bh=RIaJwXAv2CIPY/0FDHuz4E1BrCH0mzjtH5iCXkOJkoI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=AjwWNXoMZKjYf98c456Ce2Ewf8zo+umypbZTMXzBKfyiQ2gC5Vj5ELWuolMICNn8L +ysvti6pqY+o5yw9MWOUK2vN+cuPaJrIWLbdUITy6ZT43RlYJC/8cPjR6CP75eO8G6 ynlEMYx3oJW6he7IdbBYtYcpVzyQeg0hp2kCsh4Y= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Xiyu Yang , Xin Tan , John Johansen , Greg Kroah-Hartman , linux-security-module@vger.kernel.org Subject: [PATCH AUTOSEL 5.6 155/606] apparmor: Fix aa_label refcnt leak in policy_update Date: Mon, 8 Jun 2020 19:04:40 -0400 Message-Id: <20200608231211.3363633-155-sashal@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200608231211.3363633-1-sashal@kernel.org> References: <20200608231211.3363633-1-sashal@kernel.org> MIME-Version: 1.0 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: Xiyu Yang commit c6b39f070722ea9963ffe756bfe94e89218c5e63 upstream. policy_update() invokes begin_current_label_crit_section(), which returns a reference of the updated aa_label object to "label" with increased refcount. When policy_update() returns, "label" becomes invalid, so the refcount should be decreased to keep refcount balanced. The reference counting issue happens in one exception handling path of policy_update(). When aa_may_manage_policy() returns not NULL, the refcnt increased by begin_current_label_crit_section() is not decreased, causing a refcnt leak. Fix this issue by jumping to "end_section" label when aa_may_manage_policy() returns not NULL. Fixes: 5ac8c355ae00 ("apparmor: allow introspecting the loaded policy pre internal transform") Signed-off-by: Xiyu Yang Signed-off-by: Xin Tan Signed-off-by: John Johansen Signed-off-by: Greg Kroah-Hartman --- security/apparmor/apparmorfs.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/security/apparmor/apparmorfs.c b/security/apparmor/apparmorfs.c index 280741fc0f5f..f6a3ecfadf80 100644 --- a/security/apparmor/apparmorfs.c +++ b/security/apparmor/apparmorfs.c @@ -454,7 +454,7 @@ static ssize_t policy_update(u32 mask, const char __user *buf, size_t size, */ error = aa_may_manage_policy(label, ns, mask); if (error) - return error; + goto end_section; data = aa_simple_write_to_buffer(buf, size, size, pos); error = PTR_ERR(data); @@ -462,6 +462,7 @@ static ssize_t policy_update(u32 mask, const char __user *buf, size_t size, error = aa_replace_profiles(ns, label, mask, data); aa_put_loaddata(data); } +end_section: end_current_label_crit_section(label); return error; -- 2.25.1