linux/net/ipv4, branch v4.11

tcp: do not underestimate skb->truesize in tcp_trim_head()

2017-04-28T20:05:22Z

Andrey found a way to trigger the WARN_ON_ONCE(delta < len) in skb_try_coalesce() using syzkaller and a filter attached to a TCP socket over loopback interface. I believe one issue with looped skbs is that tcp_trim_head() can end up producing skb with under estimated truesize. It hardly matters for normal conditions, since packets sent over loopback are never truncated. Bytes trimmed from skb->head should not change skb truesize, since skb->head is not reallocated. Signed-off-by: Eric Dumazet Reported-by: Andrey Konovalov Tested-by: Andrey Konovalov Signed-off-by: David S. Miller

ipv4: Don't pass IP fragments to upper layer GRO handlers.

2017-04-28T20:00:38Z

Upper layer GRO handlers can not handle IP fragments, so exit GRO processing in this case. This fixes ESP GRO because the packet must be reassembled before we can decapsulate, otherwise we get authentication failures. It also aligns IPv4 to IPv6 where packets with fragmentation headers are not passed to upper layer GRO handlers. Fixes: 7785bba299a8 ("esp: Add a software GRO codepath") Signed-off-by: Steffen Klassert Signed-off-by: David S. Miller

tcp: memset ca_priv data to 0 properly

2017-04-26T18:58:32Z

Always zero out ca_priv data in tcp_assign_congestion_control() so that ca_priv data is cleared out during socket creation. Also always zero out ca_priv data in tcp_reinit_congestion_control() so that when cc algorithm is changed, ca_priv data is cleared out as well. We should still zero out ca_priv data even in TCP_CLOSE state because user could call connect() on AF_UNSPEC to disconnect the socket and leave it in TCP_CLOSE state and later call setsockopt() to switch cc algorithm on this socket. Fixes: 2b0a8c9ee ("tcp: add CDG congestion control") Reported-by: Andrey Konovalov Signed-off-by: Wei Wang Acked-by: Eric Dumazet Acked-by: Yuchung Cheng Acked-by: Neal Cardwell Signed-off-by: David S. Miller

udp: disable inner UDP checksum offloads in IPsec case

2017-04-24T17:48:54Z

Otherwise, UDP checksum offloads could corrupt ESP packets by attempting to calculate UDP checksum when this inner UDP packet is already protected by IPsec. One way to reproduce this bug is to have a VM with virtio_net driver (UFO set to ON in the guest VM); and then encapsulate all guest's Ethernet frames in Geneve; and then further encrypt Geneve with IPsec. In this case following symptoms are observed: 1. If using ixgbe NIC, then it will complain with following error message: ixgbe 0000:01:00.1: partial checksum but l4 proto=32! 2. Receiving IPsec stack will drop all the corrupted ESP packets and increase XfrmInStateProtoError counter in /proc/net/xfrm_stat. 3. iperf UDP test from the VM with packet sizes above MTU will not work at all. 4. iperf TCP test from the VM will get ridiculously low performance because. Signed-off-by: Ansis Atteka Co-authored-by: Steffen Klassert Signed-off-by: David S. Miller

ipv4: Avoid caching l3mdev dst on mismatched local route

2017-04-24T16:50:29Z

David reported that doing the following: ip li add red type vrf table 10 ip link set dev eth1 vrf red ip addr add 127.0.0.1/8 dev red ip link set dev eth1 up ip li set red up ping -c1 -w1 -I red 127.0.0.1 ip li del red when either policy routing IP rules are present or the local table lookup ip rule is before the l3mdev lookup results in a hang with these messages: unregister_netdevice: waiting for red to become free. Usage count = 1 The problem is caused by caching the dst used for sending the packet out of the specified interface on a local route with a different nexthop interface. Thus the dst could stay around until the route in the table the lookup was done is deleted which may be never. Address the problem by not forcing output device to be the l3mdev in the flow's output interface if the lookup didn't use the l3mdev. This then results in the dst using the right device according to the route. Changes in v2: - make the dev_out passed in by __ip_route_output_key_hash correct instead of checking the nh dev if FLOWI_FLAG_SKIP_NH_OIF is set as suggested by David. Fixes: 5f02ce24c2696 ("net: l3mdev: Allow the l3mdev to be a loopback") Reported-by: David Ahern Suggested-by: David Ahern Signed-off-by: Robert Shearman Acked-by: David Ahern Tested-by: David Ahern Signed-off-by: David S. Miller

net-timestamp: avoid use-after-free in ip_recv_error

2017-04-17T16:59:22Z

Syzkaller reported a use-after-free in ip_recv_error at line info->ipi_ifindex = skb->dev->ifindex; This function is called on dequeue from the error queue, at which point the device pointer may no longer be valid. Save ifindex on enqueue in __skb_complete_tx_timestamp, when the pointer is valid or NULL. Store it in temporary storage skb->cb. It is safe to reference skb->dev here, as called from device drivers or dev_queue_xmit. The exception is when called from tcp_ack_tstamp; in that case it is NULL and ifindex is set to 0 (invalid). Do not return a pktinfo cmsg if ifindex is 0. This maintains the current behavior of not returning a cmsg if skb->dev was NULL. On dequeue, the ipv4 path will cast from sock_exterr_skb to in_pktinfo. Both have ifindex as their first element, so no explicit conversion is needed. This is by design, introduced in commit 0b922b7a829c ("net: original ingress device index in PKTINFO"). For ipv6 ip6_datagram_support_cmsg converts to in6_pktinfo. Fixes: 829ae9d61165 ("net-timestamp: allow reading recv cmsg on errqueue with origin tstamp") Reported-by: Andrey Konovalov Signed-off-by: Willem de Bruijn Signed-off-by: David S. Miller

ipv4: fix a deadlock in ip_ra_control

2017-04-17T16:46:50Z

Similar to commit 87e9f0315952 ("ipv4: fix a potential deadlock in mcast getsockopt() path"), there is a deadlock scenario for IP_ROUTER_ALERT too: CPU0 CPU1 ---- ---- lock(rtnl_mutex); lock(sk_lock-AF_INET); lock(rtnl_mutex); lock(sk_lock-AF_INET); Fix this by always locking RTNL first on all setsockopt() paths. Note, after this patch ip_ra_lock is no longer needed either. Reported-by: Dmitry Vyukov Tested-by: Andrey Konovalov Signed-off-by: Cong Wang Signed-off-by: David S. Miller

Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf

2017-04-14T14:47:13Z

Pablo Neira Ayuso says: ==================== Netfilter fixes for net The following patchset contains Netfilter fixes for your net tree, they are: 1) Missing TCP header sanity check in TCPMSS target, from Eric Dumazet. 2) Incorrect event message type for related conntracks created via ctnetlink, from Liping Zhang. 3) Fix incorrect rcu locking when handling helpers from ctnetlink, from Gao feng. 4) Fix missing rcu locking when updating helper, from Liping Zhang. 5) Fix missing read_lock_bh when iterating over list of device addresses from TPROXY and redirect, also from Liping. 6) Fix crash when trying to dump expectations from conntrack with no helper via ctnetlink, from Liping. 7) Missing RCU protection to expecation list update given ctnetlink iterates over the list under rcu read lock side, from Liping too. 8) Don't dump autogenerated seed in nft_hash to userspace, this is very confusing to the user, again from Liping. 9) Fix wrong conntrack netns module refcount in ipt_CLUSTERIP, from Gao feng. ==================== Signed-off-by: David S. Miller

netfilter: ipt_CLUSTERIP: Fix wrong conntrack netns refcnt usage

2017-04-13T21:21:40Z

Current codes invoke wrongly nf_ct_netns_get in the destroy routine, it should use nf_ct_netns_put, not nf_ct_netns_get. It could cause some modules could not be unloaded. Fixes: ecb2421b5ddf ("netfilter: add and use nf_ct_netns_get/put") Signed-off-by: Gao Feng Signed-off-by: Pablo Neira Ayuso

tcp: clear saved_syn in tcp_disconnect()

2017-04-10T01:27:28Z

In the (very unlikely) case a passive socket becomes a listener, we do not want to duplicate its saved SYN headers. This would lead to double frees, use after free, and please hackers and various fuzzers Tested: 0 socket(..., SOCK_STREAM, IPPROTO_TCP) = 3 +0 setsockopt(3, IPPROTO_TCP, TCP_SAVE_SYN, [1], 4) = 0 +0 fcntl(3, F_SETFL, O_RDWR|O_NONBLOCK) = 0 +0 bind(3, ..., ...) = 0 +0 listen(3, 5) = 0 +0 < S 0:0(0) win 32972 +0 > S. 0:0(0) ack 1 <...> +.1 < . 1:1(0) ack 1 win 257 +0 accept(3, ..., ...) = 4 +0 connect(4, AF_UNSPEC, ...) = 0 +0 close(3) = 0 +0 bind(4, ..., ...) = 0 +0 listen(4, 5) = 0 +0 < S 0:0(0) win 32972 +0 > S. 0:0(0) ack 1 <...> +.1 < . 1:1(0) ack 1 win 257 Fixes: cd8ae85299d5 ("tcp: provide SYN headers for passive connections") Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller