From patchwork Wed Apr 13 06:21:30 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "liujian (CE)" X-Patchwork-Id: 12811605 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 AC858C4332F for ; Wed, 13 Apr 2022 06:19:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232111AbiDMGVu (ORCPT ); Wed, 13 Apr 2022 02:21:50 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48944 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231998AbiDMGVs (ORCPT ); Wed, 13 Apr 2022 02:21:48 -0400 Received: from szxga03-in.huawei.com (szxga03-in.huawei.com [45.249.212.189]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C61DA35DE8; Tue, 12 Apr 2022 23:19:26 -0700 (PDT) Received: from canpemm500010.china.huawei.com (unknown [172.30.72.56]) by szxga03-in.huawei.com (SkyGuard) with ESMTP id 4KdXPl1GVnzBsJX; Wed, 13 Apr 2022 14:15:07 +0800 (CST) Received: from huawei.com (10.175.101.6) by canpemm500010.china.huawei.com (7.192.105.118) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Wed, 13 Apr 2022 14:19:23 +0800 From: Liu Jian To: , , , , , , , , , , , , CC: Subject: [PATCH bpf v2 1/2] net: Enlarge offset check value from 0xffff to INT_MAX in bpf_skb_load_bytes Date: Wed, 13 Apr 2022 14:21:30 +0800 Message-ID: <20220413062131.363740-2-liujian56@huawei.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20220413062131.363740-1-liujian56@huawei.com> References: <20220413062131.363740-1-liujian56@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.175.101.6] X-ClientProxiedBy: dggems703-chm.china.huawei.com (10.3.19.180) To canpemm500010.china.huawei.com (7.192.105.118) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net The data length of skb frags + frag_list may be greater than 0xffff, and skb_header_pointer can not handle negative offset and negative len. So here INT_MAX is used to check the validity of offset and len. Add the same change to the related function skb_store_bytes. Fixes: 05c74e5e53f6 ("bpf: add bpf_skb_load_bytes helper") Signed-off-by: Liu Jian Acked-by: Song Liu --- v1->v2: change nothing, only add Acked-by tag net/core/filter.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/net/core/filter.c b/net/core/filter.c index 64470a727ef7..1571b6bc51ea 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -1687,7 +1687,7 @@ BPF_CALL_5(bpf_skb_store_bytes, struct sk_buff *, skb, u32, offset, if (unlikely(flags & ~(BPF_F_RECOMPUTE_CSUM | BPF_F_INVALIDATE_HASH))) return -EINVAL; - if (unlikely(offset > 0xffff)) + if (unlikely(offset > INT_MAX || len > INT_MAX)) return -EFAULT; if (unlikely(bpf_try_make_writable(skb, offset + len))) return -EFAULT; @@ -1722,7 +1722,7 @@ BPF_CALL_4(bpf_skb_load_bytes, const struct sk_buff *, skb, u32, offset, { void *ptr; - if (unlikely(offset > 0xffff)) + if (unlikely(offset > INT_MAX || len > INT_MAX)) goto err_clear; ptr = skb_header_pointer(skb, offset, len, to); From patchwork Wed Apr 13 06:21:31 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "liujian (CE)" X-Patchwork-Id: 12811606 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 DBCBBC433FE for ; Wed, 13 Apr 2022 06:19:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232014AbiDMGVt (ORCPT ); Wed, 13 Apr 2022 02:21:49 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48940 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231915AbiDMGVs (ORCPT ); Wed, 13 Apr 2022 02:21:48 -0400 Received: from szxga03-in.huawei.com (szxga03-in.huawei.com [45.249.212.189]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C0E0935DD4; Tue, 12 Apr 2022 23:19:26 -0700 (PDT) Received: from canpemm500010.china.huawei.com (unknown [172.30.72.56]) by szxga03-in.huawei.com (SkyGuard) with ESMTP id 4KdXPl2C26zBsJD; Wed, 13 Apr 2022 14:15:07 +0800 (CST) Received: from huawei.com (10.175.101.6) by canpemm500010.china.huawei.com (7.192.105.118) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Wed, 13 Apr 2022 14:19:24 +0800 From: Liu Jian To: , , , , , , , , , , , , CC: Subject: [PATCH bpf v2 2/2] selftests: bpf: add test for skb_load_bytes Date: Wed, 13 Apr 2022 14:21:31 +0800 Message-ID: <20220413062131.363740-3-liujian56@huawei.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20220413062131.363740-1-liujian56@huawei.com> References: <20220413062131.363740-1-liujian56@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.175.101.6] X-ClientProxiedBy: dggems703-chm.china.huawei.com (10.3.19.180) To canpemm500010.china.huawei.com (7.192.105.118) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net Use bpf_prog_test_run_opts to test the skb_load_bytes function. Tests the behavior when offset is greater than INT_MAX or a normal value. Signed-off-by: Liu Jian --- v1->v2: As Liu Song's review comments, use bpf skeleton and global variable. .../selftests/bpf/prog_tests/skb_load_bytes.c | 45 +++++++++++++++++++ .../selftests/bpf/progs/skb_load_bytes.c | 19 ++++++++ 2 files changed, 64 insertions(+) create mode 100644 tools/testing/selftests/bpf/prog_tests/skb_load_bytes.c create mode 100644 tools/testing/selftests/bpf/progs/skb_load_bytes.c diff --git a/tools/testing/selftests/bpf/prog_tests/skb_load_bytes.c b/tools/testing/selftests/bpf/prog_tests/skb_load_bytes.c new file mode 100644 index 000000000000..81cc224a0c69 --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/skb_load_bytes.c @@ -0,0 +1,45 @@ +// SPDX-License-Identifier: GPL-2.0 +#include +#include +#include "skb_load_bytes.skel.h" + +void test_skb_load_bytes(void) +{ + struct skb_load_bytes *skel; + int err, prog_fd, test_result; + struct __sk_buff skb = { 0 }; + + LIBBPF_OPTS(bpf_test_run_opts, tattr, + .data_in = &pkt_v4, + .data_size_in = sizeof(pkt_v4), + .ctx_in = &skb, + .ctx_size_in = sizeof(skb), + ); + + skel = skb_load_bytes__open_and_load(); + if (!ASSERT_OK_PTR(skel, "skel_open_and_load")) + return; + + prog_fd = bpf_program__fd(skel->progs.skb_process); + if (prog_fd < 0) + goto out; + + skel->bss->load_offset = (uint32_t)(-1); + tattr.data_out = NULL; + tattr.data_size_out = 0; + err = bpf_prog_test_run_opts(prog_fd, &tattr); + CHECK_ATTR(err != 0, "offset -1", "err %d errno %d\n", err, errno); + test_result = skel->bss->test_result; + CHECK_ATTR(test_result != -EFAULT, "offset -1", "test error\n"); + + skel->bss->load_offset = (uint32_t)10; + tattr.data_out = NULL; + tattr.data_size_out = 0; + err = bpf_prog_test_run_opts(prog_fd, &tattr); + CHECK_ATTR(err != 0, "offset 10", "err %d errno %d\n", err, errno); + test_result = skel->bss->test_result; + CHECK_ATTR(test_result != 0, "offset 10", "test error\n"); + +out: + skb_load_bytes__destroy(skel); +} diff --git a/tools/testing/selftests/bpf/progs/skb_load_bytes.c b/tools/testing/selftests/bpf/progs/skb_load_bytes.c new file mode 100644 index 000000000000..e4252fd973be --- /dev/null +++ b/tools/testing/selftests/bpf/progs/skb_load_bytes.c @@ -0,0 +1,19 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include +#include + +char _license[] SEC("license") = "GPL"; + +__u32 load_offset = 0; +int test_result = 0; + +SEC("tc") +int skb_process(struct __sk_buff *skb) +{ + char buf[16]; + + test_result = bpf_skb_load_bytes(skb, load_offset, buf, 10); + + return 0; +}