From mboxrd@z Thu Jan 1 00:00:00 1970 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 ED218C46467 for ; Mon, 16 Jan 2023 16:26:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233166AbjAPQ0w (ORCPT ); Mon, 16 Jan 2023 11:26:52 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43144 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233076AbjAPQ0M (ORCPT ); Mon, 16 Jan 2023 11:26:12 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 78788274B1 for ; Mon, 16 Jan 2023 08:14:32 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id B907FB80DC7 for ; Mon, 16 Jan 2023 16:14:30 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 269B8C433EF; Mon, 16 Jan 2023 16:14:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1673885669; bh=nduDFTynn5+kV0dyGAArArcLX8kyf/qFN1DWJTvfPbs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=nuPV6FsvQP0AyhX/6mx/JWPAgkWXrAUpq7/g6nAyjWSV0mugLVgHCXpCrxjy+EysS qHKQcwRQyv9zBU5SlUgRFOKUm+4TDI9RyAGMOE8qmKVq+7Vy3z22Dfojyjmxc02I1t BYvFo7LIixLPMKQuahMBfUZUISCmD7nUJ+VRAqTQ= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Stanislav Fomichev , Martin KaFai Lau , Sasha Levin Subject: [PATCH 5.4 140/658] bpf: Move skb->len == 0 checks into __bpf_redirect Date: Mon, 16 Jan 2023 16:43:48 +0100 Message-Id: <20230116154915.856153392@linuxfoundation.org> X-Mailer: git-send-email 2.39.0 In-Reply-To: <20230116154909.645460653@linuxfoundation.org> References: <20230116154909.645460653@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Stanislav Fomichev [ Upstream commit 114039b342014680911c35bd6b72624180fd669a ] To avoid potentially breaking existing users. Both mac/no-mac cases have to be amended; mac_header >= network_header is not enough (verified with a new test, see next patch). Fixes: fd1894224407 ("bpf: Don't redirect packets with invalid pkt_len") Signed-off-by: Stanislav Fomichev Link: https://lore.kernel.org/r/20221121180340.1983627-1-sdf@google.com Signed-off-by: Martin KaFai Lau Signed-off-by: Sasha Levin --- net/bpf/test_run.c | 3 --- net/core/filter.c | 7 ++++++- 2 files changed, 6 insertions(+), 4 deletions(-) diff --git a/net/bpf/test_run.c b/net/bpf/test_run.c index d78c4cc30a28..591d146a5308 100644 --- a/net/bpf/test_run.c +++ b/net/bpf/test_run.c @@ -201,9 +201,6 @@ static int convert___skb_to_skb(struct sk_buff *skb, struct __sk_buff *__skb) { struct qdisc_skb_cb *cb = (struct qdisc_skb_cb *)skb->cb; - if (!skb->len) - return -EINVAL; - if (!__skb) return 0; diff --git a/net/core/filter.c b/net/core/filter.c index e81f7772161a..6fd9173e18b7 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -2071,6 +2071,11 @@ static int __bpf_redirect_no_mac(struct sk_buff *skb, struct net_device *dev, { unsigned int mlen = skb_network_offset(skb); + if (unlikely(skb->len <= mlen)) { + kfree_skb(skb); + return -ERANGE; + } + if (mlen) { __skb_pull(skb, mlen); @@ -2092,7 +2097,7 @@ static int __bpf_redirect_common(struct sk_buff *skb, struct net_device *dev, u32 flags) { /* Verify that a link layer header is carried */ - if (unlikely(skb->mac_header >= skb->network_header)) { + if (unlikely(skb->mac_header >= skb->network_header || skb->len == 0)) { kfree_skb(skb); return -ERANGE; } -- 2.35.1