From patchwork Mon Nov 16 20:01:13 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Martin KaFai Lau X-Patchwork-Id: 11910649 X-Patchwork-Delegate: bpf@iogearbox.net 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=-12.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham 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 3F38AC4742C for ; Mon, 16 Nov 2020 20:01:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E1A2F20E65 for ; Mon, 16 Nov 2020 20:01:18 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=fb.com header.i=@fb.com header.b="b9iO7bY3" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727943AbgKPUBS (ORCPT ); Mon, 16 Nov 2020 15:01:18 -0500 Received: from mx0b-00082601.pphosted.com ([67.231.153.30]:29776 "EHLO mx0a-00082601.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726575AbgKPUBS (ORCPT ); Mon, 16 Nov 2020 15:01:18 -0500 Received: from pps.filterd (m0001303.ppops.net [127.0.0.1]) by m0001303.ppops.net (8.16.0.42/8.16.0.42) with SMTP id 0AGJqV6T001431 for ; Mon, 16 Nov 2020 12:01:16 -0800 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fb.com; h=from : to : cc : subject : date : message-id : mime-version : content-transfer-encoding : content-type; s=facebook; bh=W1Yp867SWEe170iVg6tuyuN/HjciEy/s51B7qWAP3jU=; b=b9iO7bY3cMXVf0XoLa65qhsudZRc0r6aKVam5bxQ/BjXwiJYL95QqmYrAmzi8laWyDIF 92WqjRdHxvRH2o3jB78KwfS8GOOP1zYeC1hZWmcuWLuEoSI1BtCOK3E+e2uUrbFPd1BU mPrtv4gqQ9TWmeSnORHBFed+FUJb16mBgyE= Received: from mail.thefacebook.com ([163.114.132.120]) by m0001303.ppops.net with ESMTP id 34tbss9udh-8 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Mon, 16 Nov 2020 12:01:16 -0800 Received: from intmgw002.08.frc2.facebook.com (2620:10d:c085:108::8) by mail.thefacebook.com (2620:10d:c085:21d::7) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.1979.3; Mon, 16 Nov 2020 12:01:14 -0800 Received: by devbig005.ftw2.facebook.com (Postfix, from userid 6611) id 79F7F2945F03; Mon, 16 Nov 2020 12:01:13 -0800 (PST) From: Martin KaFai Lau To: CC: Alexei Starovoitov , Daniel Borkmann , Jakub Kicinski , , Subject: [PATCH bpf-next] bpf: Fix the irq and nmi check in bpf_sk_storage for tracing usage Date: Mon, 16 Nov 2020 12:01:13 -0800 Message-ID: <20201116200113.2868539-1-kafai@fb.com> X-Mailer: git-send-email 2.24.1 MIME-Version: 1.0 X-FB-Internal: Safe X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.312,18.0.737 definitions=2020-11-16_10:2020-11-13,2020-11-16 signatures=0 X-Proofpoint-Spam-Details: rule=fb_default_notspam policy=fb_default score=0 mlxscore=0 suspectscore=13 impostorscore=0 adultscore=0 priorityscore=1501 phishscore=0 lowpriorityscore=0 spamscore=0 bulkscore=0 mlxlogscore=412 malwarescore=0 clxscore=1015 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2009150000 definitions=main-2011160116 X-FB-Internal: deliver Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net The intention of the current check is to avoid using bpf_sk_storage in irq and nmi. Jakub pointed out that the current check cannot do that. For example, in_serving_softirq() returns true if the softirq handling is interrupted by hard irq. Fixes: 8e4597c627fb ("bpf: Allow using bpf_sk_storage in FENTRY/FEXIT/RAW_TP") Suggested-by: Jakub Kicinski Signed-off-by: Martin KaFai Lau --- net/core/bpf_sk_storage.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/net/core/bpf_sk_storage.c b/net/core/bpf_sk_storage.c index 359908a7d3c1..a32037daa933 100644 --- a/net/core/bpf_sk_storage.c +++ b/net/core/bpf_sk_storage.c @@ -415,7 +415,7 @@ static bool bpf_sk_storage_tracing_allowed(const struct bpf_prog *prog) BPF_CALL_4(bpf_sk_storage_get_tracing, struct bpf_map *, map, struct sock *, sk, void *, value, u64, flags) { - if (!in_serving_softirq() && !in_task()) + if (in_irq() || in_nmi()) return (unsigned long)NULL; return (unsigned long)____bpf_sk_storage_get(map, sk, value, flags); @@ -424,7 +424,7 @@ BPF_CALL_4(bpf_sk_storage_get_tracing, struct bpf_map *, map, struct sock *, sk, BPF_CALL_2(bpf_sk_storage_delete_tracing, struct bpf_map *, map, struct sock *, sk) { - if (!in_serving_softirq() && !in_task()) + if (in_irq() || in_nmi()) return -EPERM; return ____bpf_sk_storage_delete(map, sk);