From patchwork Wed Aug 30 23:59:32 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: 13370835 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 C0085111BE for ; Wed, 30 Aug 2023 23:59:43 +0000 (UTC) Received: from mail.netfilter.org (mail.netfilter.org [217.70.188.207]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id E5386CC9; 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 2/5] netfilter: xt_sctp: validate the flag_info count Date: Thu, 31 Aug 2023 01:59:32 +0200 Message-Id: <20230830235935.465690-3-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: Wander Lairson Costa sctp_mt_check doesn't validate the flag_count field. An attacker can take advantage of that to trigger a OOB read and leak memory information. Add the field validation in the checkentry function. Fixes: 2e4e6a17af35 ("[NETFILTER] x_tables: Abstraction layer for {ip,ip6,arp}_tables") Cc: stable@vger.kernel.org Reported-by: Lucas Leong Signed-off-by: Wander Lairson Costa Signed-off-by: Pablo Neira Ayuso --- net/netfilter/xt_sctp.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/net/netfilter/xt_sctp.c b/net/netfilter/xt_sctp.c index e8961094a282..b46a6a512058 100644 --- a/net/netfilter/xt_sctp.c +++ b/net/netfilter/xt_sctp.c @@ -149,6 +149,8 @@ static int sctp_mt_check(const struct xt_mtchk_param *par) { const struct xt_sctp_info *info = par->matchinfo; + if (info->flag_count > ARRAY_SIZE(info->flag_info)) + return -EINVAL; if (info->flags & ~XT_SCTP_VALID_FLAGS) return -EINVAL; if (info->invflags & ~XT_SCTP_VALID_FLAGS)