linux.git/net, branch v4.13.13

netfilter: nft_set_hash: disable fast_ops for 2-len keys

2017-11-15T09:09:15+00:00

commit 0414c78f14861cb704d6e6888efd53dd36e3bdde upstream.

jhash_1word of a u16 is a different value from jhash of the same u16 with
length 2.
Since elements are always inserted in sets using jhash over the actual
klen, this would lead to incorrect lookups on fixed-size sets with a key
length of 2, as they would be inserted with hash value jhash(key, 2) and
looked up with hash value jhash_1word(key), which is different.

Example reproducer(v4.13+), using anonymous sets which always have a
fixed size:

  table inet t {
      chain c {
                  type filter hook output priority 0; policy accept;
                  tcp dport { 10001, 10003, 10005, 10007, 10009 } counter packets 4 bytes 240 reject
                  tcp dport 10001 counter packets 4 bytes 240 reject
                  tcp dport 10003 counter packets 4 bytes 240 reject
                  tcp dport 10005 counter packets 4 bytes 240 reject
                  tcp dport 10007 counter packets 0 bytes 0 reject
                  tcp dport 10009 counter packets 4 bytes 240 reject
          }
  }

then use nc -z localhost  to probe; incorrectly hashed ports will
pass through the set lookup and increment the counter of an individual
rule.

jhash being seeded with a random value, it is not deterministic which
ports will incorrectly hash, but in testing with 5 ports in the set I
always had 4 or 5 with an incorrect hash value.

Signed-off-by: Anatole Denis 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Greg Kroah-Hartman

netfilter: nat: Revert "netfilter: nat: convert nat bysrc hash to rhashtable"

2017-11-15T09:09:15+00:00

commit e1bf1687740ce1a3598a1c5e452b852ff2190682 upstream.

This reverts commit 870190a9ec9075205c0fa795a09fa931694a3ff1.

It was not a good idea. The custom hash table was a much better
fit for this purpose.

A fast lookup is not essential, in fact for most cases there is no lookup
at all because original tuple is not taken and can be used as-is.
What needs to be fast is insertion and deletion.

rhlist removal however requires a rhlist walk.
We can have thousands of entries in such a list if source port/addresses
are reused for multiple flows, if this happens removal requests are so
expensive that deletions of a few thousand flows can take several
seconds(!).

The advantages that we got from rhashtable are:
1) table auto-sizing
2) multiple locks

1) would be nice to have, but it is not essential as we have at
most one lookup per new flow, so even a million flows in the bysource
table are not a problem compared to current deletion cost.
2) is easy to add to custom hash table.

I tried to add hlist_node to rhlist to speed up rhltable_remove but this
isn't doable without changing semantics.  rhltable_remove_fast will
check that the to-be-deleted object is part of the table and that
requires a list walk that we want to avoid.

Furthermore, using hlist_node increases size of struct rhlist_head, which
in turn increases nf_conn size.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=196821
Reported-by: Ivan Babrou 
Signed-off-by: Florian Westphal 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Greg Kroah-Hartman

ipsec: Fix aborted xfrm policy dump crash

2017-11-02T08:54:49+00:00

commit 1137b5e2529a8f5ca8ee709288ecba3e68044df2 upstream.

An independent security researcher, Mohamed Ghannam, has reported
this vulnerability to Beyond Security's SecuriTeam Secure Disclosure
program.

The xfrm_dump_policy_done function expects xfrm_dump_policy to
have been called at least once or it will crash.  This can be
triggered if a dump fails because the target socket's receive
buffer is full.

This patch fixes it by using the cb->start mechanism to ensure that
the initialisation is always done regardless of the buffer situation.

Fixes: 12a169e7d8f4 ("ipsec: Put dumpers on the dump list")
Signed-off-by: Herbert Xu 
Signed-off-by: Steffen Klassert 
Signed-off-by: Greg Kroah-Hartman

cfg80211: fix connect/disconnect edge cases

2017-11-02T08:54:49+00:00

commit 51e13359cd5ea34acc62c90627603352956380af upstream.

If we try to connect while already connected/connecting, but
this fails, we set ssid_len=0 but leave current_bss hanging,
leading to errors.

Check all of this better, first of all ensuring that we can't
try to connect to a different SSID while connected/ing; ensure
that prev_bssid is set for re-association attempts even in the
case of the driver supporting the connect() method, and don't
reset ssid_len in the failure cases.

While at it, also reset ssid_len while disconnecting unless we
were connected and expect a disconnected event, and warn on a
successful connection without ssid_len being set.

Signed-off-by: Johannes Berg 
Signed-off-by: Greg Kroah-Hartman

KEYS: Fix race between updating and finding a negative key

2017-10-27T08:39:15+00:00

commit 363b02dab09b3226f3bd1420dad9c72b79a42a76 upstream.

Consolidate KEY_FLAG_INSTANTIATED, KEY_FLAG_NEGATIVE and the rejection
error into one field such that:

 (1) The instantiation state can be modified/read atomically.

 (2) The error can be accessed atomically with the state.

 (3) The error isn't stored unioned with the payload pointers.

This deals with the problem that the state is spread over three different
objects (two bits and a separate variable) and reading or updating them
atomically isn't practical, given that not only can uninstantiated keys
change into instantiated or rejected keys, but rejected keys can also turn
into instantiated keys - and someone accessing the key might not be using
any locking.

The main side effect of this problem is that what was held in the payload
may change, depending on the state.  For instance, you might observe the
key to be in the rejected state.  You then read the cached error, but if
the key semaphore wasn't locked, the key might've become instantiated
between the two reads - and you might now have something in hand that isn't
actually an error code.

The state is now KEY_IS_UNINSTANTIATED, KEY_IS_POSITIVE or a negative error
code if the key is negatively instantiated.  The key_is_instantiated()
function is replaced with key_is_positive() to avoid confusion as negative
keys are also 'instantiated'.

Additionally, barriering is included:

 (1) Order payload-set before state-set during instantiation.

 (2) Order state-read before payload-read when using the key.

Further separate barriering is necessary if RCU is being used to access the
payload content after reading the payload pointers.

Fixes: 146aa8b1453b ("KEYS: Merge the type-specific data with the payload data")
Reported-by: Eric Biggers 
Signed-off-by: David Howells 
Reviewed-by: Eric Biggers 
Signed-off-by: Greg Kroah-Hartman

can: af_can: can_pernet_init(): add missing error handling for kzalloc returning NULL

2017-10-27T08:39:11+00:00

commit 5a606223c6b5b7560da253ed52e62c67fa18e29b upstream.

This patch adds the missing check and error handling for out-of-memory
situations, when kzalloc cannot allocate memory.

Fixes: cb5635a36776 ("can: complete initial namespace support")
Acked-by: Oliver Hartkopp 
Signed-off-by: Marc Kleine-Budde 
Signed-off-by: Greg Kroah-Hartman

udp: fix bcast packet reception

2017-10-12T09:56:19+00:00

commit 996b44fcef8f216ea0b6b6e74468c5a77b5e341f upstream.

The commit bc044e8db796 ("udp: perform source validation for
mcast early demux") does not take into account that broadcast packets
lands in the same code path and they need different checks for the
source address - notably, zero source address are valid for bcast
and invalid for mcast.

As a result, 2nd and later broadcast packets with 0 source address
landing to the same socket are dropped. This breaks dhcp servers.

Since we don't have stringent performance requirements for ingress
broadcast traffic, fix it by disabling UDP early demux such traffic.

Reported-by: Hannes Frederic Sowa 
Fixes: bc044e8db796 ("udp: perform source validation for mcast early demux")
Signed-off-by: Paolo Abeni 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

udp: perform source validation for mcast early demux

2017-10-12T09:56:19+00:00

[ Upstream commit bc044e8db7962e727a75b591b9851ff2ac5cf846 ]

The UDP early demux can leverate the rx dst cache even for
multicast unconnected sockets.

In such scenario the ipv4 source address is validated only on
the first packet in the given flow. After that, when we fetch
the dst entry  from the socket rx cache, we stop enforcing
the rp_filter and we even start accepting any kind of martian
addresses.

Disabling the dst cache for unconnected multicast socket will
cause large performace regression, nearly reducing by half the
max ingress tput.

Instead we factor out a route helper to completely validate an
skb source address for multicast packets and we call it from
the UDP early demux for mcast packets landing on unconnected
sockets, after successful fetching the related cached dst entry.

This still gives a measurable, but limited performance
regression:

		rp_filter = 0		rp_filter = 1
edmux disabled:	1182 Kpps		1127 Kpps
edmux before:	2238 Kpps		2238 Kpps
edmux after:	2037 Kpps		2019 Kpps

The above figures are on top of current net tree.
Applying the net-next commit 6e617de84e87 ("net: avoid a full
fib lookup when rp_filter is disabled.") the delta with
rp_filter == 0 will decrease even more.

Fixes: 421b3885bf6d ("udp: ipv4: Add udp early demux")
Signed-off-by: Paolo Abeni 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

nl80211: Define policy for packet pattern attributes

2017-10-12T09:56:19+00:00

commit ad670233c9e1d5feb365d870e30083ef1b889177 upstream.

Define a policy for packet pattern attributes in order to fix a
potential read over the end of the buffer during nla_get_u32()
of the NL80211_PKTPAT_OFFSET attribute.

Note that the data there can always be read due to SKB allocation
(with alignment and struct skb_shared_info at the end), but the
data might be uninitialized. This could be used to leak some data
from uninitialized vmalloc() memory, but most drivers don't allow
an offset (so you'd just get -EINVAL if the data is non-zero) or
just allow it with a fixed value - 100 or 128 bytes, so anything
above that would get -EINVAL. With brcmfmac the limit is 1500 so
(at least) one byte could be obtained.

Signed-off-by: Peng Xu 
Signed-off-by: Jouni Malinen 
[rewrite description based on SKB allocation knowledge]
Signed-off-by: Johannes Berg 
Signed-off-by: Greg Kroah-Hartman

net: rtnetlink: fix info leak in RTM_GETSTATS call

2017-10-12T09:56:07+00:00

[ Upstream commit ce024f42c2e28b6bce4ecc1e891b42f57f753892 ]

When RTM_GETSTATS was added the fields of its header struct were not all
initialized when returning the result thus leaking 4 bytes of information
to user-space per rtnl_fill_statsinfo call, so initialize them now. Thanks
to Alexander Potapenko for the detailed report and bisection.

Reported-by: Alexander Potapenko 
Fixes: 10c9ead9f3c6 ("rtnetlink: add new RTM_GETSTATS message to dump link stats")
Signed-off-by: Nikolay Aleksandrov 
Acked-by: Roopa Prabhu 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman