From patchwork Thu Aug 22 00:17:07 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: 13772246 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 3C1F04C99; Thu, 22 Aug 2024 00:17:16 +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=1724285838; cv=none; b=FQI/oyoU8Y6JOd6VELrkgb/OqjtDXk2Zh1x3y/iFISAByNCMLN4uQhsr/3Ehj52vDlaCP9hyw9zzTYcDriCTceSqb4nBwfeNFtkbIAJOdIHkyDTA+VDYk/6ARFRwqm5obD2hExu3EvN/3DrgTsii4trUhd8/AhgSOh4BVwVxos8= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1724285838; c=relaxed/simple; bh=QlkbnX3So7ybXk9gnLxo2Ib8PM6TvzIwAyY14gZWxEU=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=ZYzPLOCZQcHZnNgRR0SIYlaFTx5sBguLaX/5BTdA7Ad2pRshJwTg1bMdGjZr7S6cbGIAn1Li1R9CJOiDkrYtpqan5huf300mbFFHXppwNYmcYj7urevl3pUB6E5M/U9pH32ycu3VY8kADkhIYVaCRfN5KbVg/ToG5CQbJQi2qg4= 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 02:17:07 +0200 Message-Id: <20240822001707.2116-4-pablo@netfilter.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20240822001707.2116-1-pablo@netfilter.org> References: <20240822001707.2116-1-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..dd9a392052ee 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, VLAN_HLEN)) + 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..9a9031e9ea1c 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, VLAN_HLEN)) + return false; + veth = (struct vlan_ethhdr *)skb_mac_header(skb); if (veth->h_vlan_encapsulated_proto == proto) { *offset += VLAN_HLEN;