linux-stable.git/net/ipv4, branch v3.16.50

netfilter: Fix switch statement warnings with recent gcc.

2017-11-11T13:33:54+00:00

commit c1f866767777d1c6abae0ec57effffcb72017c00 upstream.

More recent GCC warns about two kinds of switch statement uses:

1) Switching on an enumeration, but not having an explicit case
   statement for all members of the enumeration.  To show the
   compiler this is intentional, we simply add a default case
   with nothing more than a break statement.

2) Switching on a boolean value.  I think this warning is dumb
   but nevertheless you get it wholesale with -Wswitch.

This patch cures all such warnings in netfilter.

Signed-off-by: David S. Miller 
Acked-by: Pablo Neira Ayuso 
Signed-off-by: Arnd Bergmann 
Signed-off-by: Ben Hutchings

ipv4: fix NULL dereference in free_fib_info_rcu()

2017-11-11T13:33:21+00:00

commit 187e5b3ac84d3421d2de3aca949b2791fbcad554 upstream.

If fi->fib_metrics could not be allocated in fib_create_info()
we attempt to dereference a NULL pointer in free_fib_info_rcu() :

    m = fi->fib_metrics;
    if (m != &dst_default_metrics && atomic_dec_and_test(&m->refcnt))
            kfree(m);

Before my recent patch, we used to call kfree(NULL) and nothing wrong
happened.

Instead of using RCU to defer freeing while we are under memory stress,
it seems better to take immediate action.

This was reported by syzkaller team.

Fixes: 3fb07daff8e9 ("ipv4: add reference counting to metrics")
Signed-off-by: Eric Dumazet 
Reported-by: Dmitry Vyukov 
Signed-off-by: David S. Miller 
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings

ipv4: add reference counting to metrics

2017-11-11T13:33:21+00:00

commit 3fb07daff8e99243366a081e5129560734de4ada upstream.

Andrey Konovalov reported crashes in ipv4_mtu()

I could reproduce the issue with KASAN kernels, between
10.246.7.151 and 10.246.7.152 :

1) 20 concurrent netperf -t TCP_RR -H 10.246.7.152 -l 1000 &

2) At the same time run following loop :
while :
do
 ip ro add 10.246.7.152 dev eth0 src 10.246.7.151 mtu 1500
 ip ro del 10.246.7.152 dev eth0 src 10.246.7.151 mtu 1500
done

Cong Wang attempted to add back rt->fi in commit
82486aa6f1b9 ("ipv4: restore rt->fi for reference counting")
but this proved to add some issues that were complex to solve.

Instead, I suggested to add a refcount to the metrics themselves,
being a standalone object (in particular, no reference to other objects)

I tried to make this patch as small as possible to ease its backport,
instead of being super clean. Note that we believe that only ipv4 dst
need to take care of the metric refcount. But if this is wrong,
this patch adds the basic infrastructure to extend this to other
families.

Many thanks to Julian Anastasov for reviewing this patch, and Cong Wang
for his efforts on this problem.

Fixes: 2860583fe840 ("ipv4: Kill rt->fi")
Signed-off-by: Eric Dumazet 
Reported-by: Andrey Konovalov 
Reviewed-by: Julian Anastasov 
Acked-by: Cong Wang 
Signed-off-by: David S. Miller 
[bwh: Backported to 3.16:
 - Give DST_METRICS_REFCOUNTED a value of 4 and struct dst_metrics an
   alignment of 8
 - Update dst_metrics cache size
 - Adjust context]
Signed-off-by: Ben Hutchings

dst: Increase alignment of metrics to allow extra flag on pointers

2017-11-11T13:33:20+00:00

For the backport of "ipv4: add reference counting to metrics", we will
need a third flag on metrics pointers.  This was not needed upstream
as the DST_METRICS_FORCE_OVERWRITE flag has been eliminated there.
In order to use three flag bits we need to increase the alignment of
metrics from 4 to 8 bytes.

Signed-off-by: Ben Hutchings

net: avoid skb_warn_bad_offload false positives on UFO

2017-11-11T13:33:18+00:00

commit 8d63bee643f1fb53e472f0e135cae4eb99d62d19 upstream.

skb_warn_bad_offload triggers a warning when an skb enters the GSO
stack at __skb_gso_segment that does not have CHECKSUM_PARTIAL
checksum offload set.

Commit b2504a5dbef3 ("net: reduce skb_warn_bad_offload() noise")
observed that SKB_GSO_DODGY producers can trigger the check and
that passing those packets through the GSO handlers will fix it
up. But, the software UFO handler will set ip_summed to
CHECKSUM_NONE.

When __skb_gso_segment is called from the receive path, this
triggers the warning again.

Make UFO set CHECKSUM_UNNECESSARY instead of CHECKSUM_NONE. On
Tx these two are equivalent. On Rx, this better matches the
skb state (checksum computed), as CHECKSUM_NONE here means no
checksum computed.

See also this thread for context:
http://patchwork.ozlabs.org/patch/799015/

Fixes: b2504a5dbef3 ("net: reduce skb_warn_bad_offload() noise")
Signed-off-by: Willem de Bruijn 
Signed-off-by: David S. Miller 
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings

ipv4: initialize fib_trie prior to register_netdev_notifier call.

2017-11-11T13:33:05+00:00

commit 8799a221f5944a7d74516ecf46d58c28ec1d1f75 upstream.

Net stack initialization currently initializes fib-trie after the
first call to netdevice_notifier() call. In fact fib_trie initialization
needs to happen before first rtnl_register(). It does not cause any problem
since there are no devices UP at this moment, but trying to bring 'lo'
UP at initialization would make this assumption wrong and exposes the issue.

Fixes following crash

 Call Trace:
  ? alternate_node_alloc+0x76/0xa0
  fib_table_insert+0x1b7/0x4b0
  fib_magic.isra.17+0xea/0x120
  fib_add_ifaddr+0x7b/0x190
  fib_netdev_event+0xc0/0x130
  register_netdevice_notifier+0x1c1/0x1d0
  ip_fib_init+0x72/0x85
  ip_rt_init+0x187/0x1e9
  ip_init+0xe/0x1a
  inet_init+0x171/0x26c
  ? ipv4_offload_init+0x66/0x66
  do_one_initcall+0x43/0x160
  kernel_init_freeable+0x191/0x219
  ? rest_init+0x80/0x80
  kernel_init+0xe/0x150
  ret_from_fork+0x22/0x30
 Code: f6 46 23 04 74 86 4c 89 f7 e8 ae 45 01 00 49 89 c7 4d 85 ff 0f 85 7b ff ff ff 31 db eb 08 4c 89 ff e8 16 47 01 00 48 8b 44 24 38 <45> 8b 6e 14 4d 63 76 74 48 89 04 24 0f 1f 44 00 00 48 83 c4 08
 RIP: kmem_cache_alloc+0xcf/0x1c0 RSP: ffff9b1500017c28
 CR2: 0000000000000014

Fixes: 7b1a74fdbb9e ("[NETNS]: Refactor fib initialization so it can handle multiple namespaces.")
Fixes: 7f9b80529b8a ("[IPV4]: fib hash|trie initialization")

Signed-off-by: Mahesh Bandewar 
Acked-by: "Eric W. Biederman" 
Signed-off-by: David S. Miller 
Signed-off-by: Ben Hutchings

netfilter: ipt_CLUSTERIP: fix use-after-free of proc entry

2017-11-11T13:33:00+00:00

commit 3840538ad384fb7891adeeaf36624f870c51fc0e upstream.

When we delete a netns with a CLUSTERIP rule, clusterip_net_exit() is
called first, removing /proc/net/ipt_CLUSTERIP.
Then clusterip_config_entry_put() is called from clusterip_tg_destroy(),
and tries to remove its entry under /proc/net/ipt_CLUSTERIP/.

Fix this by checking that the parent directory of the entry to remove
hasn't already been deleted.

The following triggers a KASAN splat (stealing the reproducer from
202f59afd441, thanks to Jianlin Shi and Xin Long):

    ip netns add test
    ip link add veth0_in type veth peer name veth0_out
    ip link set veth0_in netns test
    ip netns exec test ip link set lo up
    ip netns exec test ip link set veth0_in up
    ip netns exec test iptables -I INPUT -d 1.2.3.4 -i veth0_in -j     \
        CLUSTERIP --new --clustermac 89:d4:47:eb:9a:fa --total-nodes 3 \
        --local-node 1 --hashmode sourceip-sourceport
    ip netns del test

Fixes: ce4ff76c15a8 ("netfilter: ipt_CLUSTERIP: make proc directory per net namespace")
Signed-off-by: Sabrina Dubroca 
Reviewed-by: Xin Long 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Ben Hutchings

ipv4/fib: don't warn when primary address is missing if in_dev is dead

2017-10-12T14:28:12+00:00

[ Upstream commit 391a20333b8393ef2e13014e6e59d192c5594471 ]

After commit fbd40ea0180a ("ipv4: Don't do expensive useless work
during inetdev destroy.") when deleting an interface,
fib_del_ifaddr() can be executed without any primary address
present on the dead interface.

The above is safe, but triggers some "bug: prim == NULL" warnings.

This commit avoids warning if the in_dev is dead

Signed-off-by: Paolo Abeni 
Signed-off-by: David S. Miller 
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings

net/route: enforce hoplimit max value

2017-10-12T14:28:12+00:00

[ Upstream commit 626abd59e51d4d8c6367e03aae252a8aa759ac78 ]

Currently, when creating or updating a route, no check is performed
in both ipv4 and ipv6 code to the hoplimit value.

The caller can i.e. set hoplimit to 256, and when such route will
 be used, packets will be sent with hoplimit/ttl equal to 0.

This commit adds checks for the RTAX_HOPLIMIT value, in both ipv4
ipv6 route code, substituting any value greater than 255 with 255.

This is consistent with what is currently done for ADVMSS and MTU
in the ipv4 code.

Signed-off-by: Paolo Abeni 
Signed-off-by: David S. Miller 
[bwh: Backported to 3.16: for IPv6, add the check to fib6_commit_metrics()]
Signed-off-by: Ben Hutchings

net: reflect mark on tcp syn ack packets

2017-10-12T14:28:01+00:00

commit e05a90ec9e1680952454ea9510da9a761a5baac9 upstream.

SYN-ACK responses on a server in response to a SYN from a client
did not get the injected skb mark that was tagged on the SYN packet.

Fixes: 84f39b08d786 ("net: support marking accepting TCP sockets")
Reviewed-by: Lorenzo Colitti 
Signed-off-by: Jamal Hadi Salim 
Signed-off-by: David S. Miller 
Signed-off-by: Ben Hutchings