From patchwork Wed Dec 1 07:34:57 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hou Tao X-Patchwork-Id: 12649259 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9B71AC4332F for ; Wed, 1 Dec 2021 07:19:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1347212AbhLAHXE (ORCPT ); Wed, 1 Dec 2021 02:23:04 -0500 Received: from szxga02-in.huawei.com ([45.249.212.188]:16330 "EHLO szxga02-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1347208AbhLAHXD (ORCPT ); Wed, 1 Dec 2021 02:23:03 -0500 Received: from dggpeml500025.china.huawei.com (unknown [172.30.72.57]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4J3r7165kqz91V7; Wed, 1 Dec 2021 15:19:09 +0800 (CST) 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 15.1.2308.20; Wed, 1 Dec 2021 15:19:42 +0800 From: Hou Tao To: Alexei Starovoitov CC: Martin KaFai Lau , Yonghong Song , Daniel Borkmann , Andrii Nakryiko , , , Subject: [PATCH bpf-next v4 1/2] bpf: clean-up bpf_verifier_vlog() for BPF_LOG_KERNEL log level Date: Wed, 1 Dec 2021 15:34:57 +0800 Message-ID: <20211201073458.2731595-2-houtao1@huawei.com> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20211201073458.2731595-1-houtao1@huawei.com> References: <20211201073458.2731595-1-houtao1@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.175.124.27] X-ClientProxiedBy: dggems706-chm.china.huawei.com (10.3.19.183) 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 An extra newline will output for bpf_log() with BPF_LOG_KERNEL level as shown below: [ 52.095704] BPF:The function test_3 has 12 arguments. Too many. [ 52.095704] [ 52.096896] Error in parsing func ptr test_3 in struct bpf_dummy_ops Now all bpf_log() are ended by newline, but not all btf_verifier_log() are ended by newline, so checking whether or not the log message has the trailing newline and adding a newline if not. Also there is no need to calculate the left userspace buffer size for kernel log output and to truncate the output by '\0' which has already been done by vscnprintf(), so only do these for userspace log output. Signed-off-by: Hou Tao Acked-by: Yonghong Song Acked-by: Martin KaFai Lau --- kernel/bpf/verifier.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 6cfd628ae3e4..722aea00d44e 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -293,13 +293,15 @@ void bpf_verifier_vlog(struct bpf_verifier_log *log, const char *fmt, WARN_ONCE(n >= BPF_VERIFIER_TMP_LOG_SIZE - 1, "verifier log line truncated - local buffer too short\n"); - n = min(log->len_total - log->len_used - 1, n); - log->kbuf[n] = '\0'; - if (log->level == BPF_LOG_KERNEL) { - pr_err("BPF:%s\n", log->kbuf); + bool newline = n > 0 && log->kbuf[n - 1] == '\n'; + + pr_err("BPF: %s%s", log->kbuf, newline ? "" : "\n"); return; } + + n = min(log->len_total - log->len_used - 1, n); + log->kbuf[n] = '\0'; if (!copy_to_user(log->ubuf + log->len_used, log->kbuf, n + 1)) log->len_used += n; else From patchwork Wed Dec 1 07:34:58 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hou Tao X-Patchwork-Id: 12649261 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1C378C433EF for ; Wed, 1 Dec 2021 07:19:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1347221AbhLAHXF (ORCPT ); Wed, 1 Dec 2021 02:23:05 -0500 Received: from szxga03-in.huawei.com ([45.249.212.189]:28204 "EHLO szxga03-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1347211AbhLAHXE (ORCPT ); Wed, 1 Dec 2021 02:23:04 -0500 Received: from dggpeml500025.china.huawei.com (unknown [172.30.72.54]) by szxga03-in.huawei.com (SkyGuard) with ESMTP id 4J3r5N4Gtwz8vkc; Wed, 1 Dec 2021 15:17:44 +0800 (CST) 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 15.1.2308.20; Wed, 1 Dec 2021 15:19:42 +0800 From: Hou Tao To: Alexei Starovoitov CC: Martin KaFai Lau , Yonghong Song , Daniel Borkmann , Andrii Nakryiko , , , Subject: [PATCH bpf-next v4 2/2] bpf: disallow BPF_LOG_KERNEL log level for bpf(BPF_BTF_LOAD) Date: Wed, 1 Dec 2021 15:34:58 +0800 Message-ID: <20211201073458.2731595-3-houtao1@huawei.com> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20211201073458.2731595-1-houtao1@huawei.com> References: <20211201073458.2731595-1-houtao1@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.175.124.27] X-ClientProxiedBy: dggems706-chm.china.huawei.com (10.3.19.183) 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 Acked-by: Martin KaFai Lau --- 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 6b9d23be1e99..308c345cd811 100644 --- a/kernel/bpf/btf.c +++ b/kernel/bpf/btf.c @@ -4472,8 +4472,7 @@ 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 722aea00d44e..f128e6799cb5 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -13969,11 +13969,11 @@ 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)) {