From patchwork Thu Aug 22 10:18:42 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pablo Neira Ayuso X-Patchwork-Id: 13773177 X-Patchwork-Delegate: kuba@kernel.org Received: from mail.netfilter.org (mail.netfilter.org [217.70.188.207]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 3D5B8176FA5; Thu, 22 Aug 2024 10:18:48 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.70.188.207 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1724321931; cv=none; b=gqYRhbz06q2yuatLUQL+iCdM6fCNl9H8sKVLjWOOp0wFh0FWDNwNu48ibbh8eiPR4emZrwrDqG2RsgWXV6PzPFadL3lTRZx0fF8UnxPZJtUSUOfLg5fq5trVvMihbpIczC/PTuTBylDxq6vwU78LzUPe9O9hnAKiP4dbUhnQsH4= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1724321931; c=relaxed/simple; bh=xDzSyLXoIJrkZXMua97tNHmvv5A088sFUZ3zo0Sc0Os=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=tMTYlkD/PRGl0OngMBJpMgoU7ELoSrABCaEXl/afFnXYaakaASaguMvQEe0GIPp8dVJAUZqjrIkgipr094GT4tkDxPEmiG1OZOTz2MElNqWR8b3u5O2dIHO4UFILTPrLUzv3/W8kuJlLcoX/f1iUbaz/yHWJFlFhcD9DYFZWUD4= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=netfilter.org; spf=pass smtp.mailfrom=netfilter.org; arc=none smtp.client-ip=217.70.188.207 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=netfilter.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=netfilter.org 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, fw@strlen.de Subject: [PATCH net 3/3] netfilter: flowtable: validate vlan header Date: Thu, 22 Aug 2024 12:18:42 +0200 Message-Id: <20240822101842.4234-4-pablo@netfilter.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20240822101842.4234-1-pablo@netfilter.org> References: <20240822101842.4234-1-pablo@netfilter.org> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Patchwork-Delegate: kuba@kernel.org Ensure there is sufficient room to access the protocol field of the VLAN header, validate it once before the flowtable lookup. ===================================================== BUG: KMSAN: uninit-value in nf_flow_offload_inet_hook+0x45a/0x5f0 net/netfilter/nf_flow_table_inet.c:32 nf_flow_offload_inet_hook+0x45a/0x5f0 net/netfilter/nf_flow_table_inet.c:32 nf_hook_entry_hookfn include/linux/netfilter.h:154 [inline] nf_hook_slow+0xf4/0x400 net/netfilter/core.c:626 nf_hook_ingress include/linux/netfilter_netdev.h:34 [inline] nf_ingress net/core/dev.c:5440 [inline] Fixes: 4cd91f7c290f ("netfilter: flowtable: add vlan support") Reported-by: syzbot+8407d9bb88cd4c6bf61a@syzkaller.appspotmail.com Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nf_flow_table_inet.c | 3 +++ net/netfilter/nf_flow_table_ip.c | 3 +++ 2 files changed, 6 insertions(+) diff --git a/net/netfilter/nf_flow_table_inet.c b/net/netfilter/nf_flow_table_inet.c index 88787b45e30d..8b541a080342 100644 --- a/net/netfilter/nf_flow_table_inet.c +++ b/net/netfilter/nf_flow_table_inet.c @@ -17,6 +17,9 @@ nf_flow_offload_inet_hook(void *priv, struct sk_buff *skb, switch (skb->protocol) { case htons(ETH_P_8021Q): + if (!pskb_may_pull(skb, skb_mac_offset(skb) + sizeof(*veth))) + return NF_ACCEPT; + veth = (struct vlan_ethhdr *)skb_mac_header(skb); proto = veth->h_vlan_encapsulated_proto; break; diff --git a/net/netfilter/nf_flow_table_ip.c b/net/netfilter/nf_flow_table_ip.c index c2c005234dcd..98edcaa37b38 100644 --- a/net/netfilter/nf_flow_table_ip.c +++ b/net/netfilter/nf_flow_table_ip.c @@ -281,6 +281,9 @@ static bool nf_flow_skb_encap_protocol(struct sk_buff *skb, __be16 proto, switch (skb->protocol) { case htons(ETH_P_8021Q): + if (!pskb_may_pull(skb, skb_mac_offset(skb) + sizeof(*veth))) + return false; + veth = (struct vlan_ethhdr *)skb_mac_header(skb); if (veth->h_vlan_encapsulated_proto == proto) { *offset += VLAN_HLEN;