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=-8.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, HK_RANDOM_FROM,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 70AE8C2BA17 for ; Sun, 5 Apr 2020 05:13:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4B7942074F for ; Sun, 5 Apr 2020 05:13:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726352AbgDEFNA (ORCPT ); Sun, 5 Apr 2020 01:13:00 -0400 Received: from mail.fudan.edu.cn ([202.120.224.10]:60366 "EHLO fudan.edu.cn" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726046AbgDEFNA (ORCPT ); Sun, 5 Apr 2020 01:13:00 -0400 Received: from localhost.localdomain (unknown [120.229.255.226]) by app1 (Coremail) with SMTP id XAUFCgA3XDjGaIlemdXLAA--.46630S3; Sun, 05 Apr 2020 13:12:41 +0800 (CST) From: Xiyu Yang To: John Johansen , James Morris , "Serge E. Hallyn" , linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org Cc: xiyuyang19@fudan.edu.cn, yuanxzhang@fudan.edu.cn, kjlu@umn.edu, Xin Tan Subject: [PATCH v2] apparmor: fix potential label refcnt leak in aa_change_profile Date: Sun, 5 Apr 2020 13:11:55 +0800 Message-Id: <1586063515-15682-1-git-send-email-xiyuyang19@fudan.edu.cn> X-Mailer: git-send-email 2.7.4 X-CM-TRANSID: XAUFCgA3XDjGaIlemdXLAA--.46630S3 X-Coremail-Antispam: 1UD129KBjvJXoW7KryfGF47WF4fCr45WrW5trb_yoW8Xw13pF 47KF1UJa1DtFy7Ka1Dta15urWak3yxJr1Yvasxu3y5Zrs8JrWUXw17ur1Uur1rZrykArsF qa43tFsYvw1UCa7anT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUkK14x267AKxVW8JVW5JwAFc2x0x2IEx4CE42xK8VAvwI8IcIk0 rVWrJVCq3wAFIxvE14AKwVWUJVWUGwA2ocxC64kIII0Yj41l84x0c7CEw4AK67xGY2AK02 1l84ACjcxK6xIIjxv20xvE14v26w1j6s0DM28EF7xvwVC0I7IYx2IY6xkF7I0E14v26r4U JVWxJr1l84ACjcxK6I8E87Iv67AKxVW0oVCq3wA2z4x0Y4vEx4A2jsIEc7CjxVAFwI0_Gc CE3s1lnxkEFVAIw20F6cxK64vIFxWle2I262IYc4CY6c8Ij28IcVAaY2xG8wAqx4xG64xv F2IEw4CE5I8CrVC2j2WlYx0E2Ix0cI8IcVAFwI0_Jr0_Jr4lYx0Ex4A2jsIE14v26r1j6r 4UMcvjeVCFs4IE7xkEbVWUJVW8JwACjcxG0xvY0x0EwIxGrwACjI8F5VA0II8E6IAqYI8I 648v4I1l42xK82IYc2Ij64vIr41l4I8I3I0E4IkC6x0Yz7v_Jr0_Gr1lx2IqxVAqx4xG67 AKxVWUJVWUGwC20s026x8GjcxK67AKxVWUGVWUWwC2zVAF1VAY17CE14v26r1q6r43MIIY rxkI7VAKI48JMIIF0xvE2Ix0cI8IcVAFwI0_Jr0_JF4lIxAIcVC0I7IYx2IY6xkF7I0E14 v26r1j6r4UMIIF0xvE42xK8VAvwI8IcIk0rVWrZr1j6s0DMIIF0xvEx4A2jsIE14v26r1j 6r4UMIIF0xvEx4A2jsIEc7CjxVAFwI0_Jr0_GrUvcSsGvfC2KfnxnUUI43ZEXa7VUbHa0D UUUUU== X-CM-SenderInfo: irzsiiysuqikmy6i3vldqovvfxof0/ Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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(). Signed-off-by: Xiyu Yang Signed-off-by: Xin Tan --- Changes in v2: - Remove unnecessary aa_get_current_label() because it gets called earlier in the fn --- security/apparmor/domain.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/security/apparmor/domain.c b/security/apparmor/domain.c index 6ceb74e0f789..a84ef030fbd7 100644 --- a/security/apparmor/domain.c +++ b/security/apparmor/domain.c @@ -1328,6 +1328,7 @@ int aa_change_profile(const char *fqname, int flags) ctx->nnp = aa_get_label(label); if (!fqname || !*fqname) { + aa_put_label(label); AA_DEBUG("no profile name"); return -EINVAL; } @@ -1346,8 +1347,6 @@ int aa_change_profile(const char *fqname, int flags) op = OP_CHANGE_PROFILE; } - label = aa_get_current_label(); - if (*fqname == '&') { stack = true; /* don't have label_parse() do stacking */ -- 2.7.4