From nobody Fri Sep 25 01:20:32 2026 Received: from cstnet.cn (smtp25.cstnet.cn [159.226.251.25]) (using TLSv1.2 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C5B0D542EE5; Thu, 17 Sep 2026 16:41:46 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=159.226.251.25 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789663309; cv=none; b=ihbN1apHgCig/6spz07j91SfpThh20ZoODMNZslBKdS3nLFzO3gHcTzpZVBvWFQlG0ks4SoJ5U4zqSMoOFvMBIUEivhy0MZiwpY5Gz32wasdxZhPKaAH/wi5T3pqHUWB3c9w8D8C4DmD5jnoRPlpYLZutLmlkjPedXv+fZo8FWg= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789663309; c=relaxed/simple; bh=iiXBV5MgplOvJ91LHs1htrM3/RFloTnXRtR+u/xWX5U=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version; b=U3a/IjttzLTZU6kbNtsCU27NrD77mSHNVO5vYSfKChlrrWl7XKdTR1bVRoW1Kwn3RzlucrvBXjbog4O+Ge7l2NfrBqJks/etPlBNPHyS9V1/xd6pzIhqQKO73FUaa/JmhaQjKXITNFxioa3wFuKpJ4nIzAAsF5ZG+oBl6xskSbs= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=iscas.ac.cn; spf=pass smtp.mailfrom=iscas.ac.cn; arc=none smtp.client-ip=159.226.251.25 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=iscas.ac.cn Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=iscas.ac.cn Received: from dfae2b116770.home.arpa (unknown [36.110.52.2]) by APP-05 (Coremail) with SMTP id zQCowAB34jxAGKxqLa+ECA--.7061S2; Fri, 18 Sep 2026 00:41:36 +0800 (CST) From: Wentao Liang To: apparmor@lists.ubuntu.com Cc: jmorris@namei.org, john.johansen@canonical.com, linux-kernel@vger.kernel.org, linux-security-module@vger.kernel.org, paul@paul-moore.com, serge@hallyn.com, Wentao Liang , stable@vger.kernel.org Subject: [PATCH] apparmor: Fix label reference leak in aa_unix_file_perm() Date: Thu, 17 Sep 2026 16:41:36 +0000 Message-Id: <20260917164136.2162858-1-vulab@iscas.ac.cn> X-Mailer: git-send-email 2.34.1 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-CM-TRANSID: zQCowAB34jxAGKxqLa+ECA--.7061S2 X-Coremail-Antispam: 1UD129KBjvdXoWrZry7tr1rKw17ur4ktr4UCFg_yoWktFcE9a s7ArnrWrWxZFs0yanFyFWI9F929a4DGFyFqa4j9FZ7G348Gr4fAF9rAr1rXrZxXw4xK345 t3WDW3sxtwnrXjkaLaAFLSUrUUUUjb8apTn2vfkv8UJUUUU8Yxn0WfASr-VFAUDa7-sFnT 9fnUUIcSsGvfJTRUUUbVkFc2x0x2IEx4CE42xK8VAvwI8IcIk0rVWrJVCq3wAFIxvE14AK wVWUJVWUGwA2ocxC64kIII0Yj41l84x0c7CEw4AK67xGY2AK021l84ACjcxK6xIIjxv20x vE14v26ryj6F1UM28EF7xvwVC0I7IYx2IY6xkF7I0E14v26r4UJVWxJr1l84ACjcxK6I8E 87Iv67AKxVWxJVW8Jr1l84ACjcxK6I8E87Iv6xkF7I0E14v26r4UJVWxJr1le2I262IYc4 CY6c8Ij28IcVAaY2xG8wAqx4xG64xvF2IEw4CE5I8CrVC2j2WlYx0E2Ix0cI8IcVAFwI0_ Jw0_WrylYx0Ex4A2jsIE14v26r4j6F4UMcvjeVCFs4IE7xkEbVWUJVW8JwACjcxG0xvY0x 0EwIxGrwACjI8F5VA0II8E6IAqYI8I648v4I1lc7CjxVAaw2AFwI0_Jw0_GFyl42xK82IY c2Ij64vIr41l42xK82IY6x8ErcxFaVAv8VW8GFyrJr1UJwCFx2IqxVCFs4IE7xkEbVWUJV W8JwC20s026c02F40E14v26r1j6r18MI8I3I0E7480Y4vE14v26r106r1rMI8E67AF67kF 1VAFwI0_Jw0_GFylIxkGc2Ij64vIr41lIxAIcVC0I7IYx2IY67AKxVWUCVW8JwCI42IY6x IIjxv20xvEc7CjxVAFwI0_Cr0_Gr1UMIIF0xvE42xK8VAvwI8IcIk0rVWUJVWUCwCI42IY 6I8E87Iv67AKxVW8JVWxJwCI42IY6I8E87Iv6xkF7I0E14v26r4UJVWxJrUvcSsGvfC2Kf nxnUUI43ZEXa7VUbUPEDUUUUU== X-CM-SenderInfo: pyxotu46lvutnvoduhdfq/1tbiCRUNA2qr9LZUgwAAsG Content-Type: text/plain; charset="utf-8" The inner block in aa_unix_file_perm() re-declares plabel, shadowing the outer variable that is released at the out label. The reference taken by aa_get_label_rcu() is thus lost when the block exits, and aa_put_label() at out is a no-op on the still NULL outer plabel, leaking one label per permission check on a non-filesystem unix socket. Drop the shadowing declaration so the outer plabel is used and released. Fixes: 88fec3526e84 ("apparmor: make sure unix socket labeling is correctly= updated.") Cc: stable@vger.kernel.org Signed-off-by: Wentao Liang --- security/apparmor/af_unix.c | 1 - 1 file changed, 1 deletion(-) diff --git a/security/apparmor/af_unix.c b/security/apparmor/af_unix.c index fdb4a9f212c3..ecb40cfe7e14 100644 --- a/security/apparmor/af_unix.c +++ b/security/apparmor/af_unix.c @@ -758,7 +758,6 @@ int aa_unix_file_perm(const struct cred *subj_cred, str= uct aa_label *label, unix_fs_perm(op, request, subj_cred, label, is_unix_fs(peer_sk) ? &peer_path : NULL)); } else if (!is_sk_fs) { - struct aa_label *plabel; struct aa_sk_ctx *pctx =3D aa_sock(peer_sk); =20 rcu_read_lock(); --=20 2.34.1