From patchwork Tue May 26 18:53:19 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 225242 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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, 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 D8BA9C433DF for ; Tue, 26 May 2020 19:27:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B4B7720721 for ; Tue, 26 May 2020 19:27:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1590521251; bh=eUVjV3AP6pVxx9BUy2BWXmtarhggMcNmDp9jlExEm9A=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=qgl0Y3YY7Xo4ErpyZNCVC3nszOTL4sL6dUIHf74tLSw9IPPIkNaKUf46qx2u1tqX6 yx+AtMjglnCVYXpHTFhmyQqqxwrtcGGpaoRD+EsnUZPcB1FDHyMs3AR55RySFqtDZT ugOjMp9RBIB2Xt8oW7ZBRLp/gu+NS2nfI/+BS/gY= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389763AbgEZT11 (ORCPT ); Tue, 26 May 2020 15:27:27 -0400 Received: from mail.kernel.org ([198.145.29.99]:59930 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2391342AbgEZTEU (ORCPT ); Tue, 26 May 2020 15:04:20 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 98A9C20849; Tue, 26 May 2020 19:04:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1590519860; bh=eUVjV3AP6pVxx9BUy2BWXmtarhggMcNmDp9jlExEm9A=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=KBLvqerzmeDSSJvdJyYUOf98KYmqS91U1PfOftr/VUWytMo2fHlh8HjxLms7oEYw5 2LrrDfeblR0V5QRkZ+5uTe+15CWvZIdyBXxIBFJtXSAQ9A7r9gKI7Wq6Y/gp1PGd0y tQ19mtAxsEInNmx1SkeXo3v0SWKubNW5pgkQMGcg= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Xiyu Yang , Xin Tan , John Johansen Subject: [PATCH 4.19 44/81] apparmor: fix potential label refcnt leak in aa_change_profile Date: Tue, 26 May 2020 20:53:19 +0200 Message-Id: <20200526183931.948240214@linuxfoundation.org> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200526183923.108515292@linuxfoundation.org> References: <20200526183923.108515292@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Xiyu Yang commit a0b845ffa0d91855532b50fc040aeb2d8338dca4 upstream. aa_change_profile() invokes aa_get_current_label(), which returns a reference of the current task's label. According to the comment of aa_get_current_label(), the returned reference must be put with aa_put_label(). However, when the original object pointed by "label" becomes unreachable because aa_change_profile() returns or a new object is assigned to "label", reference count increased by aa_get_current_label() is not decreased, causing a refcnt leak. Fix this by calling aa_put_label() before aa_change_profile() return and dropping unnecessary aa_get_current_label(). Fixes: 9fcf78cca198 ("apparmor: update domain transitions that are subsets of confinement at nnp") Signed-off-by: Xiyu Yang Signed-off-by: Xin Tan Signed-off-by: John Johansen Signed-off-by: Greg Kroah-Hartman --- security/apparmor/domain.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) --- a/security/apparmor/domain.c +++ b/security/apparmor/domain.c @@ -1338,6 +1338,7 @@ int aa_change_profile(const char *fqname ctx->nnp = aa_get_label(label); if (!fqname || !*fqname) { + aa_put_label(label); AA_DEBUG("no profile name"); return -EINVAL; } @@ -1356,8 +1357,6 @@ int aa_change_profile(const char *fqname op = OP_CHANGE_PROFILE; } - label = aa_get_current_label(); - if (*fqname == '&') { stack = true; /* don't have label_parse() do stacking */