From patchwork Mon Mar 9 22:40:17 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrii Nakryiko X-Patchwork-Id: 1251850 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Original-To: incoming-bpf@patchwork.ozlabs.org Delivered-To: patchwork-incoming-bpf@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=none (no SPF record) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=bpf-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=pass (p=none dis=none) header.from=fb.com Authentication-Results: ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=fb.com header.i=@fb.com header.a=rsa-sha256 header.s=facebook header.b=WzF4cotm; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 48btTq3mzmz9sPF for ; Tue, 10 Mar 2020 09:40:31 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727273AbgCIWk1 (ORCPT ); Mon, 9 Mar 2020 18:40:27 -0400 Received: from mx0a-00082601.pphosted.com ([67.231.145.42]:13008 "EHLO mx0a-00082601.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726656AbgCIWk1 (ORCPT ); Mon, 9 Mar 2020 18:40:27 -0400 Received: from pps.filterd (m0109334.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id 029MaIwc017040 for ; Mon, 9 Mar 2020 15:40:26 -0700 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fb.com; h=from : to : cc : subject : date : message-id : mime-version : content-type; s=facebook; bh=Ot3yvsJGq05LFkk2MrG+kC5EWFHLX7V2T/GeJ6X5cuU=; b=WzF4cotmn8FATKyjbwtTto9cmNnhb+IWirgTHOI4L0znLULFwDuX28KFrB5Mu5BPTnia ROE+qQaCjVZoz6t6osDKAbYonQ3tMYcS16cxdQuUZ8Zg62UHLhf0O/vUm/OFe6Eg3u0r I06v4n8ki/MOUGuLXiFRSJKWJ+zJCQCubG8= Received: from maileast.thefacebook.com ([163.114.130.16]) by mx0a-00082601.pphosted.com with ESMTP id 2ynu7js4nj-4 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Mon, 09 Mar 2020 15:40:26 -0700 Received: from intmgw003.08.frc2.facebook.com (2620:10d:c0a8:1b::d) by mail.thefacebook.com (2620:10d:c0a8:82::d) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.1847.3; Mon, 9 Mar 2020 15:40:24 -0700 Received: by devbig012.ftw2.facebook.com (Postfix, from userid 137359) id 7B9442EC2D75; Mon, 9 Mar 2020 15:40:23 -0700 (PDT) Smtp-Origin-Hostprefix: devbig From: Andrii Nakryiko Smtp-Origin-Hostname: devbig012.ftw2.facebook.com To: , , , , CC: , , Andrii Nakryiko Smtp-Origin-Cluster: ftw2c04 Subject: [PATCH bpf] bpf: fix cgroup ref leak in cgroup_bpf_inherit on out-of-memory Date: Mon, 9 Mar 2020 15:40:17 -0700 Message-ID: <20200309224017.1063297-1-andriin@fb.com> X-Mailer: git-send-email 2.17.1 X-FB-Internal: Safe MIME-Version: 1.0 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.138, 18.0.572 definitions=2020-03-09_11:2020-03-09,2020-03-09 signatures=0 X-Proofpoint-Spam-Details: rule=fb_default_notspam policy=fb_default score=0 spamscore=0 lowpriorityscore=0 mlxlogscore=468 priorityscore=1501 impostorscore=0 clxscore=1015 adultscore=0 phishscore=0 mlxscore=0 malwarescore=0 bulkscore=0 suspectscore=25 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2001150001 definitions=main-2003090136 X-FB-Internal: deliver Sender: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org There is no compensating cgroup_bpf_put() for each ancestor cgroup in cgroup_bpf_inherit(). If compute_effective_progs returns error, those cgroups won't be freed ever. Fix it by putting them in cleanup code path. Fixes: e10360f815ca ("bpf: cgroup: prevent out-of-order release of cgroup bpf") Signed-off-by: Andrii Nakryiko Acked-by: Roman Gushchin --- kernel/bpf/cgroup.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/kernel/bpf/cgroup.c b/kernel/bpf/cgroup.c index 9a500fadbef5..5220a67392fc 100644 --- a/kernel/bpf/cgroup.c +++ b/kernel/bpf/cgroup.c @@ -227,6 +227,9 @@ int cgroup_bpf_inherit(struct cgroup *cgrp) for (i = 0; i < NR; i++) bpf_prog_array_free(arrays[i]); + for (p = cgroup_parent(cgrp); p; p = cgroup_parent(p)) + cgroup_bpf_put(p); + percpu_ref_exit(&cgrp->bpf.refcnt); return -ENOMEM;