From patchwork Tue Mar 15 12:39:16 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Liu Jian X-Patchwork-Id: 12781386 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 D6711C433EF for ; Tue, 15 Mar 2022 12:35:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1348368AbiCOMhJ (ORCPT ); Tue, 15 Mar 2022 08:37:09 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49408 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235413AbiCOMhI (ORCPT ); Tue, 15 Mar 2022 08:37:08 -0400 Received: from szxga03-in.huawei.com (szxga03-in.huawei.com [45.249.212.189]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 22C1B53B4A; Tue, 15 Mar 2022 05:35:56 -0700 (PDT) Received: from canpemm500010.china.huawei.com (unknown [172.30.72.57]) by szxga03-in.huawei.com (SkyGuard) with ESMTP id 4KHt864HwHz9sYl; Tue, 15 Mar 2022 20:32:06 +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 15.1.2308.21; Tue, 15 Mar 2022 20:35:53 +0800 From: Liu Jian To: , , , , , , , , , , , , CC: Subject: [PATCH bpf-next] net: Use skb->len to check the validity of the parameters in bpf_skb_load_bytes Date: Tue, 15 Mar 2022 20:39:16 +0800 Message-ID: <20220315123916.110409-1-liujian56@huawei.com> X-Mailer: git-send-email 2.17.1 MIME-Version: 1.0 X-Originating-IP: [10.175.101.6] X-ClientProxiedBy: dggems705-chm.china.huawei.com (10.3.19.182) 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, so here use skb->len to check the validity of the parameters. And modify bpf_flow_dissector_load_bytes and bpf_skb_load_bytes_relative in the same way. Fixes: 05c74e5e53f6 ("bpf: add bpf_skb_load_bytes helper") Fixes: 4e1ec56cdc59 ("bpf: add skb_load_bytes_relative helper") Fixes: 089b19a9204f ("flow_dissector: switch kernel context to struct bpf_flow_dissector") Signed-off-by: Liu Jian --- net/core/filter.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/net/core/filter.c b/net/core/filter.c index 9eb785842258..61c353caf141 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -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 >= skb->len)) goto err_clear; ptr = skb_header_pointer(skb, offset, len, to); @@ -1753,10 +1753,10 @@ BPF_CALL_4(bpf_flow_dissector_load_bytes, { void *ptr; - if (unlikely(offset > 0xffff)) + if (unlikely(!ctx->skb)) goto err_clear; - if (unlikely(!ctx->skb)) + if (unlikely(offset >= ctx->skb->len)) goto err_clear; ptr = skb_header_pointer(ctx->skb, offset, len, to); @@ -1787,7 +1787,7 @@ BPF_CALL_5(bpf_skb_load_bytes_relative, const struct sk_buff *, skb, u8 *end = skb_tail_pointer(skb); u8 *start, *ptr; - if (unlikely(offset > 0xffff)) + if (unlikely(offset >= skb->len)) goto err_clear; switch (start_header) {