linux-stable.git/net, branch v3.10.76

netfilter: conntrack: disable generic tracking for known protocols

2015-04-29T08:33:59+00:00

commit db29a9508a9246e77087c5531e45b2c88ec6988b upstream.

Given following iptables ruleset:

-P FORWARD DROP
-A FORWARD -m sctp --dport 9 -j ACCEPT
-A FORWARD -p tcp --dport 80 -j ACCEPT
-A FORWARD -p tcp -m conntrack -m state ESTABLISHED,RELATED -j ACCEPT

One would assume that this allows SCTP on port 9 and TCP on port 80.
Unfortunately, if the SCTP conntrack module is not loaded, this allows
*all* SCTP communication, to pass though, i.e. -p sctp -j ACCEPT,
which we think is a security issue.

This is because on the first SCTP packet on port 9, we create a dummy
"generic l4" conntrack entry without any port information (since
conntrack doesn't know how to extract this information).

All subsequent packets that are unknown will then be in established
state since they will fallback to proto_generic and will match the
'generic' entry.

Our originally proposed version [1] completely disabled generic protocol
tracking, but Jozsef suggests to not track protocols for which a more
suitable helper is available, hence we now mitigate the issue for in
tree known ct protocol helpers only, so that at least NAT and direction
information will still be preserved for others.

 [1] http://www.spinics.net/lists/netfilter-devel/msg33430.html

Joint work with Daniel Borkmann.

Fixes CVE-2014-8160.

Signed-off-by: Florian Westphal 
Signed-off-by: Daniel Borkmann 
Acked-by: Jozsef Kadlecsik 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Zhiqiang Zhang 
Signed-off-by: Greg Kroah-Hartman

tcp: tcp_make_synack() should clear skb->tstamp

2015-04-29T08:33:55+00:00

[ Upstream commit b50edd7812852d989f2ef09dcfc729690f54a42d ]

I noticed tcpdump was giving funky timestamps for locally
generated SYNACK messages on loopback interface.

11:42:46.938990 IP 127.0.0.1.48245 > 127.0.0.2.23850: S
945476042:945476042(0) win 43690 

20:28:58.502209 IP 127.0.0.2.23850 > 127.0.0.1.48245: S
3160535375:3160535375(0) ack 945476043 win 43690 

This is because we need to clear skb->tstamp before
entering lower stack, otherwise net_timestamp_check()
does not set skb->tstamp.

Fixes: 7faee5c0d514 ("tcp: remove TCP_SKB_CB(skb)->when")
Signed-off-by: Eric Dumazet 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

tcp: fix FRTO undo on cumulative ACK of SACKed range

2015-04-29T08:33:55+00:00

[ Upstream commit 666b805150efd62f05810ff0db08f44a2370c937 ]

On processing cumulative ACKs, the FRTO code was not checking the
SACKed bit, meaning that there could be a spurious FRTO undo on a
cumulative ACK of a previously SACKed skb.

The FRTO code should only consider a cumulative ACK to indicate that
an original/unretransmitted skb is newly ACKed if the skb was not yet
SACKed.

The effect of the spurious FRTO undo would typically be to make the
connection think that all previously-sent packets were in flight when
they really weren't, leading to a stall and an RTO.

Signed-off-by: Neal Cardwell 
Signed-off-by: Yuchung Cheng 
Fixes: e33099f96d99c ("tcp: implement RFC5682 F-RTO")
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

ipv6: Don't reduce hop limit for an interface

2015-04-29T08:33:55+00:00

[ Upstream commit 6fd99094de2b83d1d4c8457f2c83483b2828e75a ]

A local route may have a lower hop_limit set than global routes do.

RFC 3756, Section 4.2.7, "Parameter Spoofing"

>   1.  The attacker includes a Current Hop Limit of one or another small
>       number which the attacker knows will cause legitimate packets to
>       be dropped before they reach their destination.

>   As an example, one possible approach to mitigate this threat is to
>   ignore very small hop limits.  The nodes could implement a
>   configurable minimum hop limit, and ignore attempts to set it below
>   said limit.

Signed-off-by: D.S. Ljungmark 
Acked-by: Hannes Frederic Sowa 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

tcp: prevent fetching dst twice in early demux code

2015-04-29T08:33:54+00:00

[ Upstream commit d0c294c53a771ae7e84506dfbd8c18c30f078735 ]

On s390x, gcc 4.8 compiles this part of tcp_v6_early_demux()

        struct dst_entry *dst = sk->sk_rx_dst;

        if (dst)
                dst = dst_check(dst, inet6_sk(sk)->rx_dst_cookie);

to code reading sk->sk_rx_dst twice, once for the test and once for
the argument of ip6_dst_check() (dst_check() is inline). This allows
ip6_dst_check() to be called with null first argument, causing a crash.

Protect sk->sk_rx_dst access by ACCESS_ONCE() both in IPv4 and IPv6
TCP early demux code.

Fixes: 41063e9dd119 ("ipv4: Early TCP socket demux.")
Fixes: c7109986db3c ("ipv6: Early TCP socket demux")
Signed-off-by: Michal Kubecek 
Acked-by: Eric Dumazet 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

remove extra definitions of U32_MAX

2015-04-29T08:33:54+00:00

commit 04f9b74e4d96d349de12fdd4e6626af4a9f75e09 upstream.

Now that the definition is centralized in , the
definitions of U32_MAX (and related) elsewhere in the kernel can be
removed.

Signed-off-by: Alex Elder 
Acked-by: Sage Weil 
Acked-by: David S. Miller 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

conditionally define U32_MAX

2015-04-29T08:33:54+00:00

commit 77719536dc00f8fd8f5abe6dadbde5331c37f996 upstream.

The symbol U32_MAX is defined in several spots.  Change these
definitions to be conditional.  This is in preparation for the next
patch, which centralizes the definition in .

Signed-off-by: Alex Elder 
Cc: Sage Weil 
Cc: David Miller 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

net: llc: use correct size for sysctl timeout entries

2015-04-19T08:10:50+00:00

commit 6b8d9117ccb4f81b1244aafa7bc70ef8fa45fc49 upstream.

The timeout entries are sizeof(int) rather than sizeof(long), which
means that when they were getting read we'd also leak kernel memory
to userspace along with the timeout values.

Signed-off-by: Sasha Levin 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

net: rds: use correct size for max unacked packets and bytes

2015-04-19T08:10:50+00:00

commit db27ebb111e9f69efece08e4cb6a34ff980f8896 upstream.

Max unacked packets/bytes is an int while sizeof(long) was used in the
sysctl table.

This means that when they were getting read we'd also leak kernel memory
to userspace along with the timeout values.

Signed-off-by: Sasha Levin 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

core, nfqueue, openvswitch: fix compilation warning

2015-04-19T08:10:50+00:00

Stable commit "core, nfqueue, openvswitch: Orphan frags in
skb_zerocopy and handle errors", upstream commit
36d5fe6a000790f56039afe26834265db0a3ad4c, was not correctly backported
and missed to change a const 'from' parameter to non-const.  This
results in a new batch of warnings:

net/netfilter/nfnetlink_queue_core.c: In function ‘nfqnl_zcopy’:
net/netfilter/nfnetlink_queue_core.c:272:2: warning: passing argument 1 of ‘skb_orphan_frags’ discards ‘const’ qualifier from pointer target type [enabled by default]
  if (unlikely(skb_orphan_frags(from, GFP_ATOMIC))) {
  ^
In file included from net/netfilter/nfnetlink_queue_core.c:18:0:
include/linux/skbuff.h:1822:19: note: expected ‘struct sk_buff *’ but argument is of type ‘const struct sk_buff *’
 static inline int skb_orphan_frags(struct sk_buff *skb, gfp_t gfp_mask)
                   ^
net/netfilter/nfnetlink_queue_core.c:273:3: warning: passing argument 1 of ‘skb_tx_error’ discards ‘const’ qualifier from pointer target type [enabled by default]
   skb_tx_error(from);
   ^
In file included from net/netfilter/nfnetlink_queue_core.c:18:0:
include/linux/skbuff.h:630:13: note: expected ‘struct sk_buff *’ but argument is of type ‘const struct sk_buff *’
 extern void skb_tx_error(struct sk_buff *skb);

Remove const from the 'from' parameter, the same as in the upstream
commit.

As far as I can see, this leaked into 3.10, 3.12, and 3.13 already.

Cc: Zoltan Kiss 
Cc: David S. Miller 
Cc: Ben Hutchings 
Cc: Greg Kroah-Hartman 
Cc: Kamal Mostafa 
Signed-off-by: Jiri Slaby 
Signed-off-by: Greg Kroah-Hartman