From patchwork Mon Apr 11 13:02:54 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "liujian (CE)" X-Patchwork-Id: 12809086 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 01926C4332F for ; Mon, 11 Apr 2022 13:00:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244175AbiDKNDA (ORCPT ); Mon, 11 Apr 2022 09:03:00 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54864 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231367AbiDKNDA (ORCPT ); Mon, 11 Apr 2022 09:03:00 -0400 Received: from szxga08-in.huawei.com (szxga08-in.huawei.com [45.249.212.255]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E04401A059; Mon, 11 Apr 2022 06:00:45 -0700 (PDT) Received: from canpemm500010.china.huawei.com (unknown [172.30.72.57]) by szxga08-in.huawei.com (SkyGuard) with ESMTP id 4KcTV2301Zz1HBjN; Mon, 11 Apr 2022 21:00:10 +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; Mon, 11 Apr 2022 21:00:42 +0800 From: Liu Jian To: , , , , , , , , , , , , CC: Subject: [PATCH bpf 1/2] net: Enlarge offset check value from 0xffff to INT_MAX in bpf_skb_load_bytes Date: Mon, 11 Apr 2022 21:02:54 +0800 Message-ID: <20220411130255.385520-2-liujian56@huawei.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20220411130255.385520-1-liujian56@huawei.com> References: <20220411130255.385520-1-liujian56@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.175.101.6] X-ClientProxiedBy: dggems702-chm.china.huawei.com (10.3.19.179) 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 --- 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 a7044e98765e..b0a3b6489701 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 Mon Apr 11 13:02:55 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "liujian (CE)" X-Patchwork-Id: 12809087 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 1B4B1C433F5 for ; Mon, 11 Apr 2022 13:00:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1346310AbiDKNDF (ORCPT ); Mon, 11 Apr 2022 09:03:05 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54896 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1346304AbiDKNDB (ORCPT ); Mon, 11 Apr 2022 09:03:01 -0400 Received: from szxga03-in.huawei.com (szxga03-in.huawei.com [45.249.212.189]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 81F451EC71; Mon, 11 Apr 2022 06:00:46 -0700 (PDT) Received: from canpemm500010.china.huawei.com (unknown [172.30.72.56]) by szxga03-in.huawei.com (SkyGuard) with ESMTP id 4KcTPm230gzBrx3; Mon, 11 Apr 2022 20:56:28 +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; Mon, 11 Apr 2022 21:00:43 +0800 From: Liu Jian To: , , , , , , , , , , , , CC: Subject: [PATCH bpf 2/2] selftests: bpf: add test for skb_load_bytes Date: Mon, 11 Apr 2022 21:02:55 +0800 Message-ID: <20220411130255.385520-3-liujian56@huawei.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20220411130255.385520-1-liujian56@huawei.com> References: <20220411130255.385520-1-liujian56@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.175.101.6] X-ClientProxiedBy: dggems702-chm.china.huawei.com (10.3.19.179) 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 behavior when offset is greater than INT_MAX or a normal value. Signed-off-by: Liu Jian --- .../selftests/bpf/prog_tests/skb_load_bytes.c | 65 +++++++++++++++++++ .../selftests/bpf/progs/skb_load_bytes.c | 37 +++++++++++ 2 files changed, 102 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..2e86f81d85f1 --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/skb_load_bytes.c @@ -0,0 +1,65 @@ +// SPDX-License-Identifier: GPL-2.0 +#include +#include + +void test_skb_load_bytes(void) +{ + struct bpf_map *test_result; + + __u32 map_key = 0; + __u32 map_value = 0; + + struct bpf_object *obj; + int err, map_fd, prog_fd; + + 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), + ); + + err = bpf_prog_test_load("./skb_load_bytes.o", BPF_PROG_TYPE_SCHED_CLS, &obj, + &prog_fd); + if (CHECK_ATTR(err, "load", "err %d errno %d\n", err, errno)) + return; + + test_result = bpf_object__find_map_by_name(obj, "test_result"); + if (CHECK_FAIL(!test_result)) + goto close_bpf_object; + + map_fd = bpf_map__fd(test_result); + if (map_fd < 0) + goto close_bpf_object; + + map_key = 0; + map_value = -1; + err = bpf_map_update_elem(map_fd, &map_key, &map_value, BPF_ANY); + if (CHECK_FAIL(err)) + goto close_bpf_object; + 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); + map_key = 1; + bpf_map_lookup_elem(map_fd, &map_key, &map_value); + CHECK_ATTR(map_value != -14, "offset -1", "get result error\n"); + + map_key = 0; + map_value = 10; + err = bpf_map_update_elem(map_fd, &map_key, &map_value, BPF_ANY); + if (CHECK_FAIL(err)) + goto close_bpf_object; + 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); + map_key = 1; + bpf_map_lookup_elem(map_fd, &map_key, &map_value); + CHECK_ATTR(map_value != 0, "offset 10", "get result error\n"); + +close_bpf_object: + bpf_object__close(obj); +} 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..1652540aa45d --- /dev/null +++ b/tools/testing/selftests/bpf/progs/skb_load_bytes.c @@ -0,0 +1,37 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include +#include + +char _license[] SEC("license") = "GPL"; + +struct { + __uint(type, BPF_MAP_TYPE_ARRAY); + __uint(max_entries, 2); + __type(key, __u32); + __type(value, __u32); +} test_result SEC(".maps"); + +SEC("tc") +int skb_process(struct __sk_buff *skb) +{ + char buf[16]; + int ret = 0; + __u32 map_key = 0; + __u32 *offset = NULL; + + offset = bpf_map_lookup_elem(&test_result, &map_key); + if (offset == NULL) { + bpf_printk("get offset failed\n"); + map_key = 1; + ret = -1; + bpf_map_update_elem(&test_result, &map_key, &ret, BPF_ANY); + return ret; + } + + ret = bpf_skb_load_bytes(skb, *offset, buf, 10); + map_key = 1; + bpf_map_update_elem(&test_result, &map_key, &ret, BPF_ANY); + + return 0; +}