From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 CCB3212C461; Tue, 30 Apr 2024 10:41:59 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714473719; cv=none; b=jiDwqmrN5Uz6j+jo1546XccAyNWWuTia8bSxh7aYHDk3m5rWFa39YPzPTZb0q4Jq03YI4utz0CXEbzPeYcIfZ7ukDWi963j5HzcR6cl7JsyrlRc8XbuRtcYLj/yGyVA12g8vJe7p2K9ZGHNmIek/Nm7vZrh+tZls3TuFb5bK71U= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714473719; c=relaxed/simple; bh=xQrmP4PA57/0H7Md8nkzWWGWtcMpqawG/BO9VEPjcc4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=r/WyT1UfvBgpPrjMd8q44Rm7Z6bpR7WuFq4B4lHxSDmZonkqXsJHG6HooEgjWrkBF+MhQ0kAeGgLYGyikA6OVqADObUR9roOKoIRTFAJM9y5VGSK72E4Wk0Iik8PqukVQw5jWaN4XHEZk5TJEJOH/Zvyx6Pvb+97k3rnmyBuB5c= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=A00XqGZ9; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="A00XqGZ9" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1427DC2BBFC; Tue, 30 Apr 2024 10:41:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1714473719; bh=xQrmP4PA57/0H7Md8nkzWWGWtcMpqawG/BO9VEPjcc4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=A00XqGZ9e6qqm9XeQpLbPh9QNNm0T75rXws7k/VIaCty93u1cdRuHYhYItRv8qcBH 9WiUpCERpjtpbkA+5WHYyklvqjow34VPyZL4P6UNB9WOWZvgyPwe8X8q0jhMU/5/ot rUSKihyP6T69CQeLgfgQiS58Cw56v+njQURPxbZ8= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, syzbot+9ee20ec1de7b3168db09@syzkaller.appspotmail.com, Eric Dumazet , Phillip Potter , Sabrina Dubroca , "David S. Miller" , Sasha Levin Subject: [PATCH 4.19 04/77] geneve: fix header validation in geneve[6]_xmit_skb Date: Tue, 30 Apr 2024 12:38:43 +0200 Message-ID: <20240430103041.247832358@linuxfoundation.org> X-Mailer: git-send-email 2.44.0 In-Reply-To: <20240430103041.111219002@linuxfoundation.org> References: <20240430103041.111219002@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 4.19-stable review patch. If anyone has any objections, please let me know. ------------------ From: Eric Dumazet [ Upstream commit d8a6213d70accb403b82924a1c229e733433a5ef ] syzbot is able to trigger an uninit-value in geneve_xmit() [1] Problem : While most ip tunnel helpers (like ip_tunnel_get_dsfield()) uses skb_protocol(skb, true), pskb_inet_may_pull() is only using skb->protocol. If anything else than ETH_P_IPV6 or ETH_P_IP is found in skb->protocol, pskb_inet_may_pull() does nothing at all. If a vlan tag was provided by the caller (af_packet in the syzbot case), the network header might not point to the correct location, and skb linear part could be smaller than expected. Add skb_vlan_inet_prepare() to perform a complete mac validation. Use this in geneve for the moment, I suspect we need to adopt this more broadly. v4 - Jakub reported v3 broke l2_tos_ttl_inherit.sh selftest - Only call __vlan_get_protocol() for vlan types. Link: https://lore.kernel.org/netdev/20240404100035.3270a7d5@kernel.org/ v2,v3 - Addressed Sabrina comments on v1 and v2 Link: https://lore.kernel.org/netdev/Zg1l9L2BNoZWZDZG@hog/ [1] BUG: KMSAN: uninit-value in geneve_xmit_skb drivers/net/geneve.c:910 [inline] BUG: KMSAN: uninit-value in geneve_xmit+0x302d/0x5420 drivers/net/geneve.c:1030 geneve_xmit_skb drivers/net/geneve.c:910 [inline] geneve_xmit+0x302d/0x5420 drivers/net/geneve.c:1030 __netdev_start_xmit include/linux/netdevice.h:4903 [inline] netdev_start_xmit include/linux/netdevice.h:4917 [inline] xmit_one net/core/dev.c:3531 [inline] dev_hard_start_xmit+0x247/0xa20 net/core/dev.c:3547 __dev_queue_xmit+0x348d/0x52c0 net/core/dev.c:4335 dev_queue_xmit include/linux/netdevice.h:3091 [inline] packet_xmit+0x9c/0x6c0 net/packet/af_packet.c:276 packet_snd net/packet/af_packet.c:3081 [inline] packet_sendmsg+0x8bb0/0x9ef0 net/packet/af_packet.c:3113 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg+0x30f/0x380 net/socket.c:745 __sys_sendto+0x685/0x830 net/socket.c:2191 __do_sys_sendto net/socket.c:2203 [inline] __se_sys_sendto net/socket.c:2199 [inline] __x64_sys_sendto+0x125/0x1d0 net/socket.c:2199 do_syscall_64+0xd5/0x1f0 entry_SYSCALL_64_after_hwframe+0x6d/0x75 Uninit was created at: slab_post_alloc_hook mm/slub.c:3804 [inline] slab_alloc_node mm/slub.c:3845 [inline] kmem_cache_alloc_node+0x613/0xc50 mm/slub.c:3888 kmalloc_reserve+0x13d/0x4a0 net/core/skbuff.c:577 __alloc_skb+0x35b/0x7a0 net/core/skbuff.c:668 alloc_skb include/linux/skbuff.h:1318 [inline] alloc_skb_with_frags+0xc8/0xbf0 net/core/skbuff.c:6504 sock_alloc_send_pskb+0xa81/0xbf0 net/core/sock.c:2795 packet_alloc_skb net/packet/af_packet.c:2930 [inline] packet_snd net/packet/af_packet.c:3024 [inline] packet_sendmsg+0x722d/0x9ef0 net/packet/af_packet.c:3113 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg+0x30f/0x380 net/socket.c:745 __sys_sendto+0x685/0x830 net/socket.c:2191 __do_sys_sendto net/socket.c:2203 [inline] __se_sys_sendto net/socket.c:2199 [inline] __x64_sys_sendto+0x125/0x1d0 net/socket.c:2199 do_syscall_64+0xd5/0x1f0 entry_SYSCALL_64_after_hwframe+0x6d/0x75 CPU: 0 PID: 5033 Comm: syz-executor346 Not tainted 6.9.0-rc1-syzkaller-00005-g928a87efa423 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/29/2024 Fixes: d13f048dd40e ("net: geneve: modify IP header check in geneve6_xmit_skb and geneve_xmit_skb") Reported-by: syzbot+9ee20ec1de7b3168db09@syzkaller.appspotmail.com Closes: https://lore.kernel.org/netdev/000000000000d19c3a06152f9ee4@google.com/ Signed-off-by: Eric Dumazet Cc: Phillip Potter Cc: Sabrina Dubroca Reviewed-by: Sabrina Dubroca Reviewed-by: Phillip Potter Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- drivers/net/geneve.c | 4 ++-- include/net/ip_tunnels.h | 33 +++++++++++++++++++++++++++++++++ 2 files changed, 35 insertions(+), 2 deletions(-) diff --git a/drivers/net/geneve.c b/drivers/net/geneve.c index 8aa04b37c5fe0..d25879c1657d0 100644 --- a/drivers/net/geneve.c +++ b/drivers/net/geneve.c @@ -852,7 +852,7 @@ static int geneve_xmit_skb(struct sk_buff *skb, struct net_device *dev, __be16 df; int err; - if (!pskb_inet_may_pull(skb)) + if (!skb_vlan_inet_prepare(skb)) return -EINVAL; sport = udp_flow_src_port(geneve->net, skb, 1, USHRT_MAX, true); @@ -898,7 +898,7 @@ static int geneve6_xmit_skb(struct sk_buff *skb, struct net_device *dev, __be16 sport; int err; - if (!pskb_inet_may_pull(skb)) + if (!skb_vlan_inet_prepare(skb)) return -EINVAL; sport = udp_flow_src_port(geneve->net, skb, 1, USHRT_MAX, true); diff --git a/include/net/ip_tunnels.h b/include/net/ip_tunnels.h index bc2ae8ce5bd45..570287d3564bb 100644 --- a/include/net/ip_tunnels.h +++ b/include/net/ip_tunnels.h @@ -346,6 +346,39 @@ static inline bool pskb_inet_may_pull(struct sk_buff *skb) return pskb_network_may_pull(skb, nhlen); } +/* Variant of pskb_inet_may_pull(). + */ +static inline bool skb_vlan_inet_prepare(struct sk_buff *skb) +{ + int nhlen = 0, maclen = ETH_HLEN; + __be16 type = skb->protocol; + + /* Essentially this is skb_protocol(skb, true) + * And we get MAC len. + */ + if (eth_type_vlan(type)) + type = __vlan_get_protocol(skb, type, &maclen); + + switch (type) { +#if IS_ENABLED(CONFIG_IPV6) + case htons(ETH_P_IPV6): + nhlen = sizeof(struct ipv6hdr); + break; +#endif + case htons(ETH_P_IP): + nhlen = sizeof(struct iphdr); + break; + } + /* For ETH_P_IPV6/ETH_P_IP we make sure to pull + * a base network header in skb->head. + */ + if (!pskb_may_pull(skb, maclen + nhlen)) + return false; + + skb_set_network_header(skb, maclen); + return true; +} + static inline int ip_encap_hlen(struct ip_tunnel_encap *e) { const struct ip_tunnel_encap_ops *ops; -- 2.43.0