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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 93CEFC433EF for ; Fri, 29 Oct 2021 13:38:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7978861056 for ; Fri, 29 Oct 2021 13:38:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231458AbhJ2Nkn (ORCPT ); Fri, 29 Oct 2021 09:40:43 -0400 Received: from szxga02-in.huawei.com ([45.249.212.188]:25325 "EHLO szxga02-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229692AbhJ2Nkh (ORCPT ); Fri, 29 Oct 2021 09:40:37 -0400 Received: from dggemv703-chm.china.huawei.com (unknown [172.30.72.55]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4Hgk0313G1zbhK0; Fri, 29 Oct 2021 21:33:23 +0800 (CST) Received: from dggpeml500025.china.huawei.com (7.185.36.35) by dggemv703-chm.china.huawei.com (10.3.19.46) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.15; Fri, 29 Oct 2021 21:38:03 +0800 Received: from huawei.com (10.175.124.27) by dggpeml500025.china.huawei.com (7.185.36.35) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.15; Fri, 29 Oct 2021 21:38:03 +0800 From: Hou Tao To: Alexei Starovoitov CC: Martin KaFai Lau , Yonghong Song , "Daniel Borkmann" , Andrii Nakryiko , , , Subject: [PATCH bpf-next v2 2/2] bpf: disallow BPF_LOG_KERNEL log level for sys(BPF_BTF_LOAD) Date: Fri, 29 Oct 2021 21:53:21 +0800 Message-ID: <20211029135321.94065-3-houtao1@huawei.com> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20211029135321.94065-1-houtao1@huawei.com> References: <20211029135321.94065-1-houtao1@huawei.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7BIT Content-Type: text/plain; charset=US-ASCII X-Originating-IP: [10.175.124.27] X-ClientProxiedBy: dggems705-chm.china.huawei.com (10.3.19.182) To dggpeml500025.china.huawei.com (7.185.36.35) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org BPF_LOG_KERNEL is only used internally, so disallow bpf_btf_load() to set log level as BPF_LOG_KERNEL. The same checking has already been done in bpf_check(), so factor out a helper to check the validity of log attributes and use it in both places. Signed-off-by: Hou Tao --- include/linux/bpf_verifier.h | 6 ++++++ kernel/bpf/btf.c | 3 +-- kernel/bpf/verifier.c | 6 +++--- 3 files changed, 10 insertions(+), 5 deletions(-) diff --git a/include/linux/bpf_verifier.h b/include/linux/bpf_verifier.h index c8a78e830fca..b36a0da8d5cf 100644 --- a/include/linux/bpf_verifier.h +++ b/include/linux/bpf_verifier.h @@ -396,6 +396,12 @@ static inline bool bpf_verifier_log_needed(const struct bpf_verifier_log *log) log->level == BPF_LOG_KERNEL); } +static inline bool bpf_verifier_log_attr_valid(const struct bpf_verifier_log *log) +{ + return (log->len_total >= 128 && log->len_total <= UINT_MAX >> 2 && + log->level && log->ubuf && !(log->level & ~BPF_LOG_MASK)); +} + #define BPF_MAX_SUBPROGS 256 struct bpf_subprog_info { diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c index dbc3ad07e21b..ea8874eaedac 100644 --- a/kernel/bpf/btf.c +++ b/kernel/bpf/btf.c @@ -4460,8 +4460,7 @@ static struct btf *btf_parse(bpfptr_t btf_data, u32 btf_data_size, log->len_total = log_size; /* log attributes have to be sane */ - if (log->len_total < 128 || log->len_total > UINT_MAX >> 8 || - !log->level || !log->ubuf) { + if (!bpf_verifier_log_attr_valid(log)) { err = -EINVAL; goto errout; } diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 22f0d2292c2c..47ad91cea7e9 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -13935,11 +13935,11 @@ int bpf_check(struct bpf_prog **prog, union bpf_attr *attr, bpfptr_t uattr) log->ubuf = (char __user *) (unsigned long) attr->log_buf; log->len_total = attr->log_size; - ret = -EINVAL; /* log attributes have to be sane */ - if (log->len_total < 128 || log->len_total > UINT_MAX >> 2 || - !log->level || !log->ubuf || log->level & ~BPF_LOG_MASK) + if (!bpf_verifier_log_attr_valid(log)) { + ret = -EINVAL; goto err_unlock; + } } if (IS_ERR(btf_vmlinux)) { -- 2.29.2