From patchwork Tue Nov 2 10:15:36 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hou Tao X-Patchwork-Id: 12598397 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 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3202BC433EF for ; Tue, 2 Nov 2021 10:00:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1E1AB6023E for ; Tue, 2 Nov 2021 10:00:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231145AbhKBKC6 (ORCPT ); Tue, 2 Nov 2021 06:02:58 -0400 Received: from szxga08-in.huawei.com ([45.249.212.255]:27096 "EHLO szxga08-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230362AbhKBKC5 (ORCPT ); Tue, 2 Nov 2021 06:02:57 -0400 Received: from dggemv711-chm.china.huawei.com (unknown [172.30.72.57]) by szxga08-in.huawei.com (SkyGuard) with ESMTP id 4Hk5202dJZz1DJ6Q; Tue, 2 Nov 2021 17:58:16 +0800 (CST) Received: from dggpeml500025.china.huawei.com (7.185.36.35) by dggemv711-chm.china.huawei.com (10.1.198.66) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.15; Tue, 2 Nov 2021 18:00:18 +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; Tue, 2 Nov 2021 18:00:18 +0800 From: Hou Tao To: Alexei Starovoitov CC: Martin KaFai Lau , Yonghong Song , "Daniel Borkmann" , Andrii Nakryiko , , , Subject: [PATCH bpf-next v3 2/2] bpf: disallow BPF_LOG_KERNEL log level for bpf(BPF_BTF_LOAD) Date: Tue, 2 Nov 2021 18:15:36 +0800 Message-ID: <20211102101536.2958763-3-houtao1@huawei.com> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20211102101536.2958763-1-houtao1@huawei.com> References: <20211102101536.2958763-1-houtao1@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.175.124.27] X-ClientProxiedBy: dggems701-chm.china.huawei.com (10.3.19.178) To dggpeml500025.china.huawei.com (7.185.36.35) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net 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. Fixes: 8580ac9404f6 ("bpf: Process in-kernel BTF") Signed-off-by: Hou Tao Acked-by: Yonghong Song --- include/linux/bpf_verifier.h | 7 +++++++ kernel/bpf/btf.c | 3 +-- kernel/bpf/verifier.c | 6 +++--- 3 files changed, 11 insertions(+), 5 deletions(-) diff --git a/include/linux/bpf_verifier.h b/include/linux/bpf_verifier.h index c8a78e830fca..a3d17601a5a7 100644 --- a/include/linux/bpf_verifier.h +++ b/include/linux/bpf_verifier.h @@ -396,6 +396,13 @@ 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, u32 max_total) +{ + return log->len_total >= 128 && log->len_total <= max_total && + 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..657c6b48c616 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, UINT_MAX >> 8)) { err = -EINVAL; goto errout; } diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 77beaa46329a..19a52ff384ec 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, UINT_MAX >> 2)) { + ret = -EINVAL; goto err_unlock; + } } if (IS_ERR(btf_vmlinux)) {