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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7FDA1C3DA7A for ; Wed, 28 Dec 2022 16:38:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233589AbiL1Qhi (ORCPT ); Wed, 28 Dec 2022 11:37:38 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53668 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234981AbiL1Qgh (ORCPT ); Wed, 28 Dec 2022 11:36:37 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BF4CF19C3A for ; Wed, 28 Dec 2022 08:33:01 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 5CC8D61541 for ; Wed, 28 Dec 2022 16:33:01 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6E65BC433D2; Wed, 28 Dec 2022 16:33:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1672245180; bh=pm5Zv/Er1KLMVxZNDI/ktZnJaPYbszTji8K/IG4IT1M=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=QAQ2VmWvTeBl/0I1RhsB2CUVudHuK5nGc1wIAcvLTirSq9uZyiT8/7UK8PWEeatxa F433eXqbahXy0XVUzPtq8zvsanXtxKKCzzZlKdw39+VqJQrCl9hkRQ9bQqkLUq5Yrs o8fNTD6J+R1p+iDdvirMnBP0FD8ZVS5lB6Uvpjz0= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Milan Landaverde , Martin KaFai Lau , Daniel Borkmann , Stanislav Fomichev , Sasha Levin Subject: [PATCH 6.0 0846/1073] bpf: prevent leak of lsm program after failed attach Date: Wed, 28 Dec 2022 15:40:34 +0100 Message-Id: <20221228144351.000064682@linuxfoundation.org> X-Mailer: git-send-email 2.39.0 In-Reply-To: <20221228144328.162723588@linuxfoundation.org> References: <20221228144328.162723588@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Milan Landaverde [ Upstream commit e89f3edffb860a0f54a9ed16deadb7a4a1fa3862 ] In [0], we added the ability to bpf_prog_attach LSM programs to cgroups, but in our validation to make sure the prog is meant to be attached to BPF_LSM_CGROUP, we return too early if the check fails. This results in lack of decrementing prog's refcnt (through bpf_prog_put) leaving the LSM program alive past the point of the expected lifecycle. This fix allows for the decrement to take place. [0] https://lore.kernel.org/all/20220628174314.1216643-4-sdf@google.com/ Fixes: 69fd337a975c ("bpf: per-cgroup lsm flavor") Signed-off-by: Milan Landaverde Signed-off-by: Martin KaFai Lau Signed-off-by: Daniel Borkmann Reviewed-by: Stanislav Fomichev Link: https://lore.kernel.org/r/20221213175714.31963-1-milan@mdaverde.com Signed-off-by: Sasha Levin --- kernel/bpf/syscall.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index 0e758911d963..6b6fb7237ebe 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -3505,9 +3505,9 @@ static int bpf_prog_attach(const union bpf_attr *attr) case BPF_PROG_TYPE_LSM: if (ptype == BPF_PROG_TYPE_LSM && prog->expected_attach_type != BPF_LSM_CGROUP) - return -EINVAL; - - ret = cgroup_bpf_prog_attach(attr, ptype, prog); + ret = -EINVAL; + else + ret = cgroup_bpf_prog_attach(attr, ptype, prog); break; default: ret = -EINVAL; -- 2.35.1