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 D5DA815ADBC; Sun, 24 Mar 2024 23:15:37 +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=1711322138; cv=none; b=Z24M3aIl0DLFx/LTFgd7qeZl6O9KyRyRY1BNZCodqDeE6Ofg4+QdgTwRdG64BppXrpCuvAUgLQx7HBpN4EV8VIVY2MfRXzNVjwqWqV05KWz1lxY3UByctMEVrWpIwh/McSu8rbwWB6rwoUzY2W8Gmx+p9IoOBG2Zk9G+dGn8i4w= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711322138; c=relaxed/simple; bh=ReSb+PURtghOe59gp1kwYuKIhFFT+cRPnByasQcJXdY=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Udw6CAluPCKiSAgPG5wDzFeMkEUgNoe5OdILWVoeQ1BdBc2yAocH8vl2OlKsnpEHhREQknX7tJDKs5WzG4kFpNqiufiPW/HFjbgNurSiSjbuXjCiMMHRhOUeShAMx/k64k0uavV33yTk6bR3itVmNfIgz7ydeG8n3eOB3hkJxn8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=iv4HOnVJ; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="iv4HOnVJ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0815CC433C7; Sun, 24 Mar 2024 23:15:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1711322137; bh=ReSb+PURtghOe59gp1kwYuKIhFFT+cRPnByasQcJXdY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=iv4HOnVJDO0jShGTRZKb4rCmvaQqJ1dOdvmC8NbEDIhIOv2b0vXOFHMKIYhqgXEAD iwgK01ZlyhkjSp0vR2pfZg8TshVoKXn5T8ffJd96PaKLcPq3pDAXl5yYo2KCcozxPL wQZX2hfJuVBRdW4RshntriJJSJtofT1UO6G+UWA6lokzuP0lU/5v1zxchFJKpqPdyK bSKNBeE/U0OQN1miqY36uhZz7SB9g3xift7WQgfI1Zov2mzKMX+n59BBlxjtEhUj2Z 4uvBg5cHHVkW+cLBWLoOgVPSn1xssTnySekvcuYgrfH6u1VI9xoL8nHBbEgnjsVkWb ftH1bv4f+QGAA== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Eric Dumazet , syzbot , "David S . Miller" , Sasha Levin Subject: [PATCH 6.1 214/451] net: ip_tunnel: make sure to pull inner header in ip_tunnel_rcv() Date: Sun, 24 Mar 2024 19:08:10 -0400 Message-ID: <20240324231207.1351418-215-sashal@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240324231207.1351418-1-sashal@kernel.org> References: <20240324231207.1351418-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit From: Eric Dumazet [ Upstream commit b0ec2abf98267f14d032102551581c833b0659d3 ] Apply the same fix than ones found in : 8d975c15c0cd ("ip6_tunnel: make sure to pull inner header in __ip6_tnl_rcv()") 1ca1ba465e55 ("geneve: make sure to pull inner header in geneve_rx()") We have to save skb->network_header in a temporary variable in order to be able to recompute the network_header pointer after a pskb_inet_may_pull() call. pskb_inet_may_pull() makes sure the needed headers are in skb->head. syzbot reported: BUG: KMSAN: uninit-value in __INET_ECN_decapsulate include/net/inet_ecn.h:253 [inline] BUG: KMSAN: uninit-value in INET_ECN_decapsulate include/net/inet_ecn.h:275 [inline] BUG: KMSAN: uninit-value in IP_ECN_decapsulate include/net/inet_ecn.h:302 [inline] BUG: KMSAN: uninit-value in ip_tunnel_rcv+0xed9/0x2ed0 net/ipv4/ip_tunnel.c:409 __INET_ECN_decapsulate include/net/inet_ecn.h:253 [inline] INET_ECN_decapsulate include/net/inet_ecn.h:275 [inline] IP_ECN_decapsulate include/net/inet_ecn.h:302 [inline] ip_tunnel_rcv+0xed9/0x2ed0 net/ipv4/ip_tunnel.c:409 __ipgre_rcv+0x9bc/0xbc0 net/ipv4/ip_gre.c:389 ipgre_rcv net/ipv4/ip_gre.c:411 [inline] gre_rcv+0x423/0x19f0 net/ipv4/ip_gre.c:447 gre_rcv+0x2a4/0x390 net/ipv4/gre_demux.c:163 ip_protocol_deliver_rcu+0x264/0x1300 net/ipv4/ip_input.c:205 ip_local_deliver_finish+0x2b8/0x440 net/ipv4/ip_input.c:233 NF_HOOK include/linux/netfilter.h:314 [inline] ip_local_deliver+0x21f/0x490 net/ipv4/ip_input.c:254 dst_input include/net/dst.h:461 [inline] ip_rcv_finish net/ipv4/ip_input.c:449 [inline] NF_HOOK include/linux/netfilter.h:314 [inline] ip_rcv+0x46f/0x760 net/ipv4/ip_input.c:569 __netif_receive_skb_one_core net/core/dev.c:5534 [inline] __netif_receive_skb+0x1a6/0x5a0 net/core/dev.c:5648 netif_receive_skb_internal net/core/dev.c:5734 [inline] netif_receive_skb+0x58/0x660 net/core/dev.c:5793 tun_rx_batched+0x3ee/0x980 drivers/net/tun.c:1556 tun_get_user+0x53b9/0x66e0 drivers/net/tun.c:2009 tun_chr_write_iter+0x3af/0x5d0 drivers/net/tun.c:2055 call_write_iter include/linux/fs.h:2087 [inline] new_sync_write fs/read_write.c:497 [inline] vfs_write+0xb6b/0x1520 fs/read_write.c:590 ksys_write+0x20f/0x4c0 fs/read_write.c:643 __do_sys_write fs/read_write.c:655 [inline] __se_sys_write fs/read_write.c:652 [inline] __x64_sys_write+0x93/0xd0 fs/read_write.c:652 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcf/0x1e0 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x63/0x6b Uninit was created at: __alloc_pages+0x9a6/0xe00 mm/page_alloc.c:4590 alloc_pages_mpol+0x62b/0x9d0 mm/mempolicy.c:2133 alloc_pages+0x1be/0x1e0 mm/mempolicy.c:2204 skb_page_frag_refill+0x2bf/0x7c0 net/core/sock.c:2909 tun_build_skb drivers/net/tun.c:1686 [inline] tun_get_user+0xe0a/0x66e0 drivers/net/tun.c:1826 tun_chr_write_iter+0x3af/0x5d0 drivers/net/tun.c:2055 call_write_iter include/linux/fs.h:2087 [inline] new_sync_write fs/read_write.c:497 [inline] vfs_write+0xb6b/0x1520 fs/read_write.c:590 ksys_write+0x20f/0x4c0 fs/read_write.c:643 __do_sys_write fs/read_write.c:655 [inline] __se_sys_write fs/read_write.c:652 [inline] __x64_sys_write+0x93/0xd0 fs/read_write.c:652 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcf/0x1e0 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x63/0x6b Fixes: c54419321455 ("GRE: Refactor GRE tunneling code.") Reported-by: syzbot Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- net/ipv4/ip_tunnel.c | 15 ++++++++++++++- 1 file changed, 14 insertions(+), 1 deletion(-) diff --git a/net/ipv4/ip_tunnel.c b/net/ipv4/ip_tunnel.c index 328f9068c6a43..3445e576b05bc 100644 --- a/net/ipv4/ip_tunnel.c +++ b/net/ipv4/ip_tunnel.c @@ -364,7 +364,7 @@ int ip_tunnel_rcv(struct ip_tunnel *tunnel, struct sk_buff *skb, bool log_ecn_error) { const struct iphdr *iph = ip_hdr(skb); - int err; + int nh, err; #ifdef CONFIG_NET_IPGRE_BROADCAST if (ipv4_is_multicast(iph->daddr)) { @@ -390,8 +390,21 @@ int ip_tunnel_rcv(struct ip_tunnel *tunnel, struct sk_buff *skb, tunnel->i_seqno = ntohl(tpi->seq) + 1; } + /* Save offset of outer header relative to skb->head, + * because we are going to reset the network header to the inner header + * and might change skb->head. + */ + nh = skb_network_header(skb) - skb->head; + skb_set_network_header(skb, (tunnel->dev->type == ARPHRD_ETHER) ? ETH_HLEN : 0); + if (!pskb_inet_may_pull(skb)) { + DEV_STATS_INC(tunnel->dev, rx_length_errors); + DEV_STATS_INC(tunnel->dev, rx_errors); + goto drop; + } + iph = (struct iphdr *)(skb->head + nh); + err = IP_ECN_decapsulate(iph, skb); if (unlikely(err)) { if (log_ecn_error) -- 2.43.0