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 3CBD012C48B; Tue, 30 Apr 2024 11:22:10 +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=1714476130; cv=none; b=SyPy/OEAGFbrwrGZvQ1afECieyNhEQ9ssZcVgTXhZW9kdRE2pJU5dCTpUV8XDSp4t1Q77IKjceyDcJMFNnFjkVHDtE9LFOm/ksbRBdNPU4m1hUKF4uxYFbgKwd9scXl6QGhyBKh8TK5hbr8VkixI6K21QWnC2JglvOMUbnirD00= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714476130; c=relaxed/simple; bh=xhFP+WbYin6OXddjjiIBBvzmjTamYtef+8+IlOy3usQ=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=s95BaElv790/NMZxBdSHHsTrpgYTRCHO41B93JJFobwFDTPJNVGmFR6RMDyC+zvtcRZcdUYWdeTbSQcs0ogcPboUKmcTKjC4lG8qlg88Vy24c/MtqdYT3aeww6coN6M7UJnS4/3PBPdxS9YXBqw2/3G2pTl8gmEDuMwOgG2Bg14= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=bKnaB/Je; 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="bKnaB/Je" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B4B88C2BBFC; Tue, 30 Apr 2024 11:22:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1714476130; bh=xhFP+WbYin6OXddjjiIBBvzmjTamYtef+8+IlOy3usQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=bKnaB/JeA0ZB3zubc8TxAhQPq/uPmfe/TOOh8edi/vCooiwaso1oikJK8ys41ElGM +sWvuWNYeN+ftRc7DOpTfhVN6kPcw0a02dhrPKDk4ZPWvOx3GWryBZo+21E840CECg cbPADIs0LMMWQC8jQAljGddyPj0rvGFoFnl6zZqc= 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 5.4 006/107] geneve: fix header validation in geneve[6]_xmit_skb Date: Tue, 30 Apr 2024 12:39:26 +0200 Message-ID: <20240430103044.845509492@linuxfoundation.org> X-Mailer: git-send-email 2.44.0 In-Reply-To: <20240430103044.655968143@linuxfoundation.org> References: <20240430103044.655968143@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 5.4-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 f932e4120cb6c..961cbd2b377d1 100644 --- a/drivers/net/geneve.c +++ b/drivers/net/geneve.c @@ -904,7 +904,7 @@ static int geneve_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); @@ -970,7 +970,7 @@ 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 36376f8b84dac..3a04e2ccfb393 100644 --- a/include/net/ip_tunnels.h +++ b/include/net/ip_tunnels.h @@ -329,6 +329,39 @@ 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