From patchwork Wed Aug 30 23:59:31 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pablo Neira Ayuso X-Patchwork-Id: 13370833 X-Patchwork-Delegate: kuba@kernel.org Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 48EE98C05 for ; Wed, 30 Aug 2023 23:59:42 +0000 (UTC) Received: from mail.netfilter.org (mail.netfilter.org [217.70.188.207]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 71A85CD2; Wed, 30 Aug 2023 16:59:41 -0700 (PDT) From: Pablo Neira Ayuso To: netfilter-devel@vger.kernel.org Cc: davem@davemloft.net, netdev@vger.kernel.org, kuba@kernel.org, pabeni@redhat.com, edumazet@google.com Subject: [PATCH net 1/5] netfilter: nft_exthdr: Fix non-linear header modification Date: Thu, 31 Aug 2023 01:59:31 +0200 Message-Id: <20230830235935.465690-2-pablo@netfilter.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20230830235935.465690-1-pablo@netfilter.org> References: <20230830235935.465690-1-pablo@netfilter.org> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00,SPF_HELO_NONE, SPF_PASS autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net X-Patchwork-Delegate: kuba@kernel.org From: Xiao Liang Fix skb_ensure_writable() size. Don't use nft_tcp_header_pointer() to make it explicit that pointers point to the packet (not local buffer). Fixes: 99d1712bc41c ("netfilter: exthdr: tcp option set support") Fixes: 7890cbea66e7 ("netfilter: exthdr: add support for tcp option removal") Cc: stable@vger.kernel.org Signed-off-by: Xiao Liang Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nft_exthdr.c | 20 ++++++++------------ 1 file changed, 8 insertions(+), 12 deletions(-) diff --git a/net/netfilter/nft_exthdr.c b/net/netfilter/nft_exthdr.c index 7f856ceb3a66..a9844eefedeb 100644 --- a/net/netfilter/nft_exthdr.c +++ b/net/netfilter/nft_exthdr.c @@ -238,7 +238,12 @@ static void nft_exthdr_tcp_set_eval(const struct nft_expr *expr, if (!tcph) goto err; + if (skb_ensure_writable(pkt->skb, nft_thoff(pkt) + tcphdr_len)) + goto err; + + tcph = (struct tcphdr *)(pkt->skb->data + nft_thoff(pkt)); opt = (u8 *)tcph; + for (i = sizeof(*tcph); i < tcphdr_len - 1; i += optl) { union { __be16 v16; @@ -253,15 +258,6 @@ static void nft_exthdr_tcp_set_eval(const struct nft_expr *expr, if (i + optl > tcphdr_len || priv->len + priv->offset > optl) goto err; - if (skb_ensure_writable(pkt->skb, - nft_thoff(pkt) + i + priv->len)) - goto err; - - tcph = nft_tcp_header_pointer(pkt, sizeof(buff), buff, - &tcphdr_len); - if (!tcph) - goto err; - offset = i + priv->offset; switch (priv->len) { @@ -325,9 +321,9 @@ static void nft_exthdr_tcp_strip_eval(const struct nft_expr *expr, if (skb_ensure_writable(pkt->skb, nft_thoff(pkt) + tcphdr_len)) goto drop; - opt = (u8 *)nft_tcp_header_pointer(pkt, sizeof(buff), buff, &tcphdr_len); - if (!opt) - goto err; + tcph = (struct tcphdr *)(pkt->skb->data + nft_thoff(pkt)); + opt = (u8 *)tcph; + for (i = sizeof(*tcph); i < tcphdr_len - 1; i += optl) { unsigned int j;