linux.git/net/ipv6, branch v4.9-rc5

ip6_tunnel: Update skb->protocol to ETH_P_IPV6 in ip6_tnl_xmit()

2016-10-29T18:49:31+00:00

This patch updates skb->protocol to ETH_P_IPV6 in ip6_tnl_xmit() when an
IPv6 header is installed to a socket buffer.

This is not a cosmetic change.  Without updating this value, GSO packets
transmitted through an ipip6 tunnel have the protocol of ETH_P_IP and
skb_mac_gso_segment() will attempt to call gso_segment() for IPv4,
which results in the packets being dropped.

Fixes: b8921ca83eed ("ip4ip6: Support for GSO/GRO")
Signed-off-by: Eli Cooper 
Signed-off-by: David S. Miller

inet: Fix missing return value in inet6_hash

2016-10-29T16:01:49+00:00

As part of a series to implement faster SO_REUSEPORT lookups,
commit 086c653f5862 ("sock: struct proto hash function may error")
added return values to protocol hash functions and
commit 496611d7b5ea ("inet: create IPv6-equivalent inet_hash function")
implemented a new hash function for IPv6.  However, the latter does
not respect the former's convention.

This properly propagates the hash errors in the IPv6 case.

Fixes: 496611d7b5ea ("inet: create IPv6-equivalent inet_hash function")
Reported-by: Soheil Hassas Yeganeh 
Signed-off-by: Craig Gallek 
Acked-by: Soheil Hassas Yeganeh 
Signed-off-by: David S. Miller

net: ipv6: Do not consider link state for nexthop validation

2016-10-27T20:33:12+00:00

Similar to IPv4, do not consider link state when validating next hops.

Currently, if the link is down default routes can fail to insert:
 $ ip -6 ro add vrf blue default via 2100:2::64 dev eth2
 RTNETLINK answers: No route to host

With this patch the command succeeds.

Fixes: 8c14586fc320 ("net: ipv6: Use passed in table for nexthop lookups")
Signed-off-by: David Ahern 
Signed-off-by: David S. Miller

net: ipv6: Fix processing of RAs in presence of VRF

2016-10-27T20:30:52+00:00

rt6_add_route_info and rt6_add_dflt_router were updated to pull the FIB
table from the device index, but the corresponding rt6_get_route_info
and rt6_get_dflt_router functions were not leading to the failure to
process RA's:

    ICMPv6: RA: ndisc_router_discovery failed to add default route

Fix the 'get' functions by using the table id associated with the
device when applicable.

Also, now that default routes can be added to tables other than the
default table, rt6_purge_dflt_routers needs to be updated as well to
look at all tables. To handle that efficiently, add a flag to the table
denoting if it is has a default route via RA.

Fixes: ca254490c8dfd ("net: Add VRF support to IPv6 stack")
Signed-off-by: David Ahern 
Signed-off-by: David S. Miller

udp: fix IP_CHECKSUM handling

2016-10-26T21:33:22+00:00

First bug was added in commit ad6f939ab193 ("ip: Add offset parameter to
ip_cmsg_recv") : Tom missed that ipv4 udp messages could be received on
AF_INET6 socket. ip_cmsg_recv(msg, skb) should have been replaced by
ip_cmsg_recv_offset(msg, skb, sizeof(struct udphdr));

Then commit e6afc8ace6dd ("udp: remove headers from UDP packets before
queueing") forgot to adjust the offsets now UDP headers are pulled
before skb are put in receive queue.

Fixes: ad6f939ab193 ("ip: Add offset parameter to ip_cmsg_recv")
Fixes: e6afc8ace6dd ("udp: remove headers from UDP packets before queueing")
Signed-off-by: Eric Dumazet 
Cc: Sam Kumar 
Cc: Willem de Bruijn 
Tested-by: Willem de Bruijn 
Signed-off-by: David S. Miller

ipv6: do not increment mac header when it's unset

2016-10-23T21:38:58+00:00

Otherwise we'll overflow the integer. This occurs when layer 3 tunneled
packets are handed off to the IPv6 layer.

Signed-off-by: Jason A. Donenfeld 
Signed-off-by: David S. Miller

ipv6: fix a potential deadlock in do_ipv6_setsockopt()

2016-10-21T15:29:02+00:00

Baozeng reported this deadlock case:

       CPU0                    CPU1
       ----                    ----
  lock([  165.136033] sk_lock-AF_INET6);
                               lock([  165.136033] rtnl_mutex);
                               lock([  165.136033] sk_lock-AF_INET6);
  lock([  165.136033] rtnl_mutex);

Similar to commit 87e9f0315952
("ipv4: fix a potential deadlock in mcast getsockopt() path")
this is due to we still have a case, ipv6_sock_mc_close(),
where we acquire sk_lock before rtnl_lock. Close this deadlock
with the similar solution, that is always acquire rtnl lock first.

Fixes: baf606d9c9b1 ("ipv4,ipv6: grab rtnl before locking the socket")
Reported-by: Baozeng Ding 
Tested-by: Baozeng Ding 
Cc: Marcelo Ricardo Leitner 
Signed-off-by: Cong Wang 
Reviewed-by: Marcelo Ricardo Leitner 
Signed-off-by: David S. Miller

udp: must lock the socket in udp_disconnect()

2016-10-20T18:45:52+00:00

Baozeng Ding reported KASAN traces showing uses after free in
udp_lib_get_port() and other related UDP functions.

A CONFIG_DEBUG_PAGEALLOC=y kernel would eventually crash.

I could write a reproducer with two threads doing :

static int sock_fd;
static void *thr1(void *arg)
{
	for (;;) {
		connect(sock_fd, (const struct sockaddr *)arg,
			sizeof(struct sockaddr_in));
	}
}

static void *thr2(void *arg)
{
	struct sockaddr_in unspec;

	for (;;) {
		memset(&unspec, 0, sizeof(unspec));
	        connect(sock_fd, (const struct sockaddr *)&unspec,
			sizeof(unspec));
        }
}

Problem is that udp_disconnect() could run without holding socket lock,
and this was causing list corruptions.

Signed-off-by: Eric Dumazet 
Reported-by: Baozeng Ding 
Signed-off-by: David S. Miller

net: add recursion limit to GRO

2016-10-20T18:32:22+00:00

Currently, GRO can do unlimited recursion through the gro_receive
handlers.  This was fixed for tunneling protocols by limiting tunnel GRO
to one level with encap_mark, but both VLAN and TEB still have this
problem.  Thus, the kernel is vulnerable to a stack overflow, if we
receive a packet composed entirely of VLAN headers.

This patch adds a recursion counter to the GRO layer to prevent stack
overflow.  When a gro_receive function hits the recursion limit, GRO is
aborted for this skb and it is processed normally.  This recursion
counter is put in the GRO CB, but could be turned into a percpu counter
if we run out of space in the CB.

Thanks to Vladimír Beneš  for the initial bug report.

Fixes: CVE-2016-7039
Fixes: 9b174d88c257 ("net: Add Transparent Ethernet Bridging GRO support.")
Fixes: 66e5133f19e9 ("vlan: Add GRO support for non hardware accelerated vlan")
Signed-off-by: Sabrina Dubroca 
Reviewed-by: Jiri Benc 
Acked-by: Hannes Frederic Sowa 
Acked-by: Tom Herbert 
Signed-off-by: David S. Miller

ipv6: properly prevent temp_prefered_lft sysctl race

2016-10-20T18:29:11+00:00

The check for an underflow of tmp_prefered_lft is always false
because tmp_prefered_lft is unsigned. The intention of the check
was to guard against racing with an update of the
temp_prefered_lft sysctl, potentially resulting in an underflow.

As suggested by David Miller, the best way to prevent the race is
by reading the sysctl variable using READ_ONCE.

Signed-off-by: Jiri Bohac 
Reported-by: Julia Lawall 
Fixes: 76506a986dc3 ("IPv6: fix DESYNC_FACTOR")
Signed-off-by: David S. Miller