From patchwork Thu Mar 17 13:59:40 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "liujian (CE)" X-Patchwork-Id: 12784047 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 874D5C433FE for ; Thu, 17 Mar 2022 13:56:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233971AbiCQN5m (ORCPT ); Thu, 17 Mar 2022 09:57:42 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44400 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229562AbiCQN5l (ORCPT ); Thu, 17 Mar 2022 09:57:41 -0400 Received: from szxga01-in.huawei.com (szxga01-in.huawei.com [45.249.212.187]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8ED2E11CF77; Thu, 17 Mar 2022 06:56:25 -0700 (PDT) Received: from canpemm500010.china.huawei.com (unknown [172.30.72.56]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4KK7tl0p89zfYwD; Thu, 17 Mar 2022 21:54:55 +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; Thu, 17 Mar 2022 21:56:23 +0800 From: Liu Jian To: , , , , , , , , , , , , CC: Subject: [PATCH bpf-next] net: Enlarge offset check value from 0xffff to 0x7fffffff in bpf_skb_load_bytes Date: Thu, 17 Mar 2022 21:59:40 +0800 Message-ID: <20220317135940.358774-1-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, and skb_header_pointer can not handle negative offset and negative len. So here 0x7ffffff is used to check the validity of offset and len. Fixes: 05c74e5e53f6 ("bpf: add bpf_skb_load_bytes helper") Signed-off-by: Liu Jian --- net/core/filter.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/core/filter.c b/net/core/filter.c index 9eb785842258..236578e1b618 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 > 0x7ffffffff || len > 0x7fffffff)) goto err_clear; ptr = skb_header_pointer(skb, offset, len, to);