<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-toradex.git/net/netfilter, branch v3.10.56</title>
<subtitle>Linux kernel for Apalis and Colibri modules</subtitle>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/'/>
<entry>
<title>netfilter: nf_conntrack: avoid large timeout for mid-stream pickup</title>
<updated>2014-10-05T21:54:15+00:00</updated>
<author>
<name>Florian Westphal</name>
<email>fw@strlen.de</email>
</author>
<published>2013-06-13T15:31:28+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=961a14671f6f79285672b76740eb87eb44ff5058'/>
<id>961a14671f6f79285672b76740eb87eb44ff5058</id>
<content type='text'>
commit 6547a221871f139cc56328a38105d47c14874cbe upstream.

When loose tracking is enabled (default), non-syn packets cause
creation of new conntracks in established state with default timeout for
established state (5 days).  This causes the table to fill up with UNREPLIED
when the 'new ack' packet happened to be the last-ack of a previous,
already timed-out connection.

Consider:

A 192.168.x.52792 &gt; 10.184.y.80: F, 426:426(0) ack 9237 win 255
B 10.184.y.80 &gt; 192.168.x.52792: ., ack 427 win 123
&lt;61 second pause&gt;
C 10.184.y.80 &gt; 192.168.x.52792: F, 9237:9237(0) ack 427 win 123
D 192.168.x.52792 &gt; 10.184.y.80: ., ack 9238 win 255

B moves conntrack to CLOSE_WAIT and will kill it after 60 second timeout,
C is ignored (FIN set), but last packet (D) causes new ct with 5-days timeout.

Use UNACK timeout (5 minutes) instead to get rid of these entries sooner
when in ESTABLISHED state without having seen traffic in both directions.

Signed-off-by: Florian Westphal &lt;fw@strlen.de&gt;
Acked-by: Jozsef Kadlecsik &lt;kadlec@blackhole.kfki.hu&gt;
Signed-off-by: Pablo Neira Ayuso &lt;pablo@netfilter.org&gt;
Cc: Florian Koch &lt;florian.koch1981@gmail.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 6547a221871f139cc56328a38105d47c14874cbe upstream.

When loose tracking is enabled (default), non-syn packets cause
creation of new conntracks in established state with default timeout for
established state (5 days).  This causes the table to fill up with UNREPLIED
when the 'new ack' packet happened to be the last-ack of a previous,
already timed-out connection.

Consider:

A 192.168.x.52792 &gt; 10.184.y.80: F, 426:426(0) ack 9237 win 255
B 10.184.y.80 &gt; 192.168.x.52792: ., ack 427 win 123
&lt;61 second pause&gt;
C 10.184.y.80 &gt; 192.168.x.52792: F, 9237:9237(0) ack 427 win 123
D 192.168.x.52792 &gt; 10.184.y.80: ., ack 9238 win 255

B moves conntrack to CLOSE_WAIT and will kill it after 60 second timeout,
C is ignored (FIN set), but last packet (D) causes new ct with 5-days timeout.

Use UNACK timeout (5 minutes) instead to get rid of these entries sooner
when in ESTABLISHED state without having seen traffic in both directions.

Signed-off-by: Florian Westphal &lt;fw@strlen.de&gt;
Acked-by: Jozsef Kadlecsik &lt;kadlec@blackhole.kfki.hu&gt;
Signed-off-by: Pablo Neira Ayuso &lt;pablo@netfilter.org&gt;
Cc: Florian Koch &lt;florian.koch1981@gmail.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>ipvs: fix ipv6 hook registration for local replies</title>
<updated>2014-10-05T21:54:15+00:00</updated>
<author>
<name>Julian Anastasov</name>
<email>ja@ssi.bg</email>
</author>
<published>2014-08-22T14:53:41+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=a1b7f13b63e431c141715ecc183d92409982ed63'/>
<id>a1b7f13b63e431c141715ecc183d92409982ed63</id>
<content type='text'>
commit eb90b0c734ad793d5f5bf230a9e9a4dcc48df8aa upstream.

commit fc604767613b6d2036cdc35b660bc39451040a47
("ipvs: changes for local real server") from 2.6.37
introduced DNAT support to local real server but the
IPv6 LOCAL_OUT handler ip_vs_local_reply6() is
registered incorrectly as IPv4 hook causing any outgoing
IPv4 traffic to be dropped depending on the IP header values.

Chris tracked down the problem to CONFIG_IP_VS_IPV6=y
Bug report: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1349768

Reported-by: Chris J Arges &lt;chris.j.arges@canonical.com&gt;
Tested-by: Chris J Arges &lt;chris.j.arges@canonical.com&gt;
Signed-off-by: Julian Anastasov &lt;ja@ssi.bg&gt;
Signed-off-by: Simon Horman &lt;horms@verge.net.au&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit eb90b0c734ad793d5f5bf230a9e9a4dcc48df8aa upstream.

commit fc604767613b6d2036cdc35b660bc39451040a47
("ipvs: changes for local real server") from 2.6.37
introduced DNAT support to local real server but the
IPv6 LOCAL_OUT handler ip_vs_local_reply6() is
registered incorrectly as IPv4 hook causing any outgoing
IPv4 traffic to be dropped depending on the IP header values.

Chris tracked down the problem to CONFIG_IP_VS_IPV6=y
Bug report: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1349768

Reported-by: Chris J Arges &lt;chris.j.arges@canonical.com&gt;
Tested-by: Chris J Arges &lt;chris.j.arges@canonical.com&gt;
Signed-off-by: Julian Anastasov &lt;ja@ssi.bg&gt;
Signed-off-by: Simon Horman &lt;horms@verge.net.au&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>ipvs: Maintain all DSCP and ECN bits for ipv6 tun forwarding</title>
<updated>2014-10-05T21:54:14+00:00</updated>
<author>
<name>Alex Gartrell</name>
<email>agartrell@fb.com</email>
</author>
<published>2014-07-16T22:57:34+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=787fcb84098e4f9fdea75d777f010229c393690d'/>
<id>787fcb84098e4f9fdea75d777f010229c393690d</id>
<content type='text'>
commit 76f084bc10004b3050b2cff9cfac29148f1f6088 upstream.

Previously, only the four high bits of the tclass were maintained in the
ipv6 case.  This matches the behavior of ipv4, though whether or not we
should reflect ECN bits may be up for debate.

Signed-off-by: Alex Gartrell &lt;agartrell@fb.com&gt;
Acked-by: Julian Anastasov &lt;ja@ssi.bg&gt;
Signed-off-by: Simon Horman &lt;horms@verge.net.au&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 76f084bc10004b3050b2cff9cfac29148f1f6088 upstream.

Previously, only the four high bits of the tclass were maintained in the
ipv6 case.  This matches the behavior of ipv4, though whether or not we
should reflect ECN bits may be up for debate.

Signed-off-by: Alex Gartrell &lt;agartrell@fb.com&gt;
Acked-by: Julian Anastasov &lt;ja@ssi.bg&gt;
Signed-off-by: Simon Horman &lt;horms@verge.net.au&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>ipvs: avoid netns exit crash on ip_vs_conn_drop_conntrack</title>
<updated>2014-10-05T21:54:14+00:00</updated>
<author>
<name>Julian Anastasov</name>
<email>ja@ssi.bg</email>
</author>
<published>2014-07-10T06:24:01+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=a5114ef14123a6da5a62d389ed3dacbfc3a94541'/>
<id>a5114ef14123a6da5a62d389ed3dacbfc3a94541</id>
<content type='text'>
commit 2627b7e15c5064ddd5e578e4efd948d48d531a3f upstream.

commit 8f4e0a18682d91 ("IPVS netns exit causes crash in conntrack")
added second ip_vs_conn_drop_conntrack call instead of just adding
the needed check. As result, the first call still can cause
crash on netns exit. Remove it.

Signed-off-by: Julian Anastasov &lt;ja@ssi.bg&gt;
Signed-off-by: Hans Schillstrom &lt;hans@schillstrom.com&gt;
Signed-off-by: Simon Horman &lt;horms@verge.net.au&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 2627b7e15c5064ddd5e578e4efd948d48d531a3f upstream.

commit 8f4e0a18682d91 ("IPVS netns exit causes crash in conntrack")
added second ip_vs_conn_drop_conntrack call instead of just adding
the needed check. As result, the first call still can cause
crash on netns exit. Remove it.

Signed-off-by: Julian Anastasov &lt;ja@ssi.bg&gt;
Signed-off-by: Hans Schillstrom &lt;hans@schillstrom.com&gt;
Signed-off-by: Simon Horman &lt;horms@verge.net.au&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>inetpeer: get rid of ip_id_count</title>
<updated>2014-08-14T01:24:15+00:00</updated>
<author>
<name>Eric Dumazet</name>
<email>edumazet@google.com</email>
</author>
<published>2014-06-02T12:26:03+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=ff1f69a89a613223c57c13190a6c9be928ac4b9d'/>
<id>ff1f69a89a613223c57c13190a6c9be928ac4b9d</id>
<content type='text'>
[ Upstream commit 73f156a6e8c1074ac6327e0abd1169e95eb66463 ]

Ideally, we would need to generate IP ID using a per destination IP
generator.

linux kernels used inet_peer cache for this purpose, but this had a huge
cost on servers disabling MTU discovery.

1) each inet_peer struct consumes 192 bytes

2) inetpeer cache uses a binary tree of inet_peer structs,
   with a nominal size of ~66000 elements under load.

3) lookups in this tree are hitting a lot of cache lines, as tree depth
   is about 20.

4) If server deals with many tcp flows, we have a high probability of
   not finding the inet_peer, allocating a fresh one, inserting it in
   the tree with same initial ip_id_count, (cf secure_ip_id())

5) We garbage collect inet_peer aggressively.

IP ID generation do not have to be 'perfect'

Goal is trying to avoid duplicates in a short period of time,
so that reassembly units have a chance to complete reassembly of
fragments belonging to one message before receiving other fragments
with a recycled ID.

We simply use an array of generators, and a Jenkin hash using the dst IP
as a key.

ipv6_select_ident() is put back into net/ipv6/ip6_output.c where it
belongs (it is only used from this file)

secure_ip_id() and secure_ipv6_id() no longer are needed.

Rename ip_select_ident_more() to ip_select_ident_segs() to avoid
unnecessary decrement/increment of the number of segments.

Signed-off-by: Eric Dumazet &lt;edumazet@google.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 73f156a6e8c1074ac6327e0abd1169e95eb66463 ]

Ideally, we would need to generate IP ID using a per destination IP
generator.

linux kernels used inet_peer cache for this purpose, but this had a huge
cost on servers disabling MTU discovery.

1) each inet_peer struct consumes 192 bytes

2) inetpeer cache uses a binary tree of inet_peer structs,
   with a nominal size of ~66000 elements under load.

3) lookups in this tree are hitting a lot of cache lines, as tree depth
   is about 20.

4) If server deals with many tcp flows, we have a high probability of
   not finding the inet_peer, allocating a fresh one, inserting it in
   the tree with same initial ip_id_count, (cf secure_ip_id())

5) We garbage collect inet_peer aggressively.

IP ID generation do not have to be 'perfect'

Goal is trying to avoid duplicates in a short period of time,
so that reassembly units have a chance to complete reassembly of
fragments belonging to one message before receiving other fragments
with a recycled ID.

We simply use an array of generators, and a Jenkin hash using the dst IP
as a key.

ipv6_select_ident() is put back into net/ipv6/ip6_output.c where it
belongs (it is only used from this file)

secure_ip_id() and secure_ipv6_id() no longer are needed.

Rename ip_select_ident_more() to ip_select_ident_segs() to avoid
unnecessary decrement/increment of the number of segments.

Signed-off-by: Eric Dumazet &lt;edumazet@google.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>core, nfqueue, openvswitch: Orphan frags in skb_zerocopy and handle errors</title>
<updated>2014-07-31T19:53:52+00:00</updated>
<author>
<name>Zoltan Kiss</name>
<email>zoltan.kiss@citrix.com</email>
</author>
<published>2014-03-26T22:37:45+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=c5f0c0e7525443add533495e93ba8de6feab2396'/>
<id>c5f0c0e7525443add533495e93ba8de6feab2396</id>
<content type='text'>
commit 36d5fe6a000790f56039afe26834265db0a3ad4c upstream.

skb_zerocopy can copy elements of the frags array between skbs, but it doesn't
orphan them. Also, it doesn't handle errors, so this patch takes care of that
as well, and modify the callers accordingly. skb_tx_error() is also added to
the callers so they will signal the failed delivery towards the creator of the
skb.

Signed-off-by: Zoltan Kiss &lt;zoltan.kiss@citrix.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
[bwh: Backported to 3.13: skb_zerocopy() is new in 3.14, but was moved from a
 static function in nfnetlink_queue.  We need to patch that and its caller, but
 not openvswitch.]
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 36d5fe6a000790f56039afe26834265db0a3ad4c upstream.

skb_zerocopy can copy elements of the frags array between skbs, but it doesn't
orphan them. Also, it doesn't handle errors, so this patch takes care of that
as well, and modify the callers accordingly. skb_tx_error() is also added to
the callers so they will signal the failed delivery towards the creator of the
skb.

Signed-off-by: Zoltan Kiss &lt;zoltan.kiss@citrix.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
[bwh: Backported to 3.13: skb_zerocopy() is new in 3.14, but was moved from a
 static function in nfnetlink_queue.  We need to patch that and its caller, but
 not openvswitch.]
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>ipvs: Fix panic due to non-linear skb</title>
<updated>2014-07-07T01:54:15+00:00</updated>
<author>
<name>Peter Christensen</name>
<email>pch@ordbogen.com</email>
</author>
<published>2014-05-24T19:40:12+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=25ca1ecb9c6f0940657d4b249c50f3233063c839'/>
<id>25ca1ecb9c6f0940657d4b249c50f3233063c839</id>
<content type='text'>
commit f44a5f45f544561302e855e7bd104e5f506ec01b upstream.

Receiving a ICMP response to an IPIP packet in a non-linear skb could
cause a kernel panic in __skb_pull.

The problem was introduced in
commit f2edb9f7706dcb2c0d9a362b2ba849efe3a97f5e ("ipvs: implement
passive PMTUD for IPIP packets").

Signed-off-by: Peter Christensen &lt;pch@ordbogen.com&gt;
Acked-by: Julian Anastasov &lt;ja@ssi.bg&gt;
Signed-off-by: Simon Horman &lt;horms@verge.net.au&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit f44a5f45f544561302e855e7bd104e5f506ec01b upstream.

Receiving a ICMP response to an IPIP packet in a non-linear skb could
cause a kernel panic in __skb_pull.

The problem was introduced in
commit f2edb9f7706dcb2c0d9a362b2ba849efe3a97f5e ("ipvs: implement
passive PMTUD for IPIP packets").

Signed-off-by: Peter Christensen &lt;pch@ordbogen.com&gt;
Acked-by: Julian Anastasov &lt;ja@ssi.bg&gt;
Signed-off-by: Simon Horman &lt;horms@verge.net.au&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>net: Use netlink_ns_capable to verify the permisions of netlink messages</title>
<updated>2014-06-26T19:12:37+00:00</updated>
<author>
<name>Eric W. Biederman</name>
<email>ebiederm@xmission.com</email>
</author>
<published>2014-04-23T21:29:27+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=1141a455802884d3bcbcf6b30e1d65d09cf286e1'/>
<id>1141a455802884d3bcbcf6b30e1d65d09cf286e1</id>
<content type='text'>
[ Upstream commit 90f62cf30a78721641e08737bda787552428061e ]

It is possible by passing a netlink socket to a more privileged
executable and then to fool that executable into writing to the socket
data that happens to be valid netlink message to do something that
privileged executable did not intend to do.

To keep this from happening replace bare capable and ns_capable calls
with netlink_capable, netlink_net_calls and netlink_ns_capable calls.
Which act the same as the previous calls except they verify that the
opener of the socket had the desired permissions as well.

Reported-by: Andy Lutomirski &lt;luto@amacapital.net&gt;
Signed-off-by: "Eric W. Biederman" &lt;ebiederm@xmission.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 90f62cf30a78721641e08737bda787552428061e ]

It is possible by passing a netlink socket to a more privileged
executable and then to fool that executable into writing to the socket
data that happens to be valid netlink message to do something that
privileged executable did not intend to do.

To keep this from happening replace bare capable and ns_capable calls
with netlink_capable, netlink_net_calls and netlink_ns_capable calls.
Which act the same as the previous calls except they verify that the
opener of the socket had the desired permissions as well.

Reported-by: Andy Lutomirski &lt;luto@amacapital.net&gt;
Signed-off-by: "Eric W. Biederman" &lt;ebiederm@xmission.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>netfilter: nf_conntrack_dccp: fix skb_header_pointer API usages</title>
<updated>2014-04-03T19:01:05+00:00</updated>
<author>
<name>Daniel Borkmann</name>
<email>dborkman@redhat.com</email>
</author>
<published>2014-01-05T23:57:54+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=b086eb683c73fb6a506eae277f65eeac597a6f16'/>
<id>b086eb683c73fb6a506eae277f65eeac597a6f16</id>
<content type='text'>
commit b22f5126a24b3b2f15448c3f2a254fc10cbc2b92 upstream.

Some occurences in the netfilter tree use skb_header_pointer() in
the following way ...

  struct dccp_hdr _dh, *dh;
  ...
  skb_header_pointer(skb, dataoff, sizeof(_dh), &amp;dh);

... where dh itself is a pointer that is being passed as the copy
buffer. Instead, we need to use &amp;_dh as the forth argument so that
we're copying the data into an actual buffer that sits on the stack.

Currently, we probably could overwrite memory on the stack (e.g.
with a possibly mal-formed DCCP packet), but unintentionally, as
we only want the buffer to be placed into _dh variable.

Fixes: 2bc780499aa3 ("[NETFILTER]: nf_conntrack: add DCCP protocol support")
Signed-off-by: Daniel Borkmann &lt;dborkman@redhat.com&gt;
Signed-off-by: Pablo Neira Ayuso &lt;pablo@netfilter.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit b22f5126a24b3b2f15448c3f2a254fc10cbc2b92 upstream.

Some occurences in the netfilter tree use skb_header_pointer() in
the following way ...

  struct dccp_hdr _dh, *dh;
  ...
  skb_header_pointer(skb, dataoff, sizeof(_dh), &amp;dh);

... where dh itself is a pointer that is being passed as the copy
buffer. Instead, we need to use &amp;_dh as the forth argument so that
we're copying the data into an actual buffer that sits on the stack.

Currently, we probably could overwrite memory on the stack (e.g.
with a possibly mal-formed DCCP packet), but unintentionally, as
we only want the buffer to be placed into _dh variable.

Fixes: 2bc780499aa3 ("[NETFILTER]: nf_conntrack: add DCCP protocol support")
Signed-off-by: Daniel Borkmann &lt;dborkman@redhat.com&gt;
Signed-off-by: Pablo Neira Ayuso &lt;pablo@netfilter.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>netfilter: nf_nat: fix access to uninitialized buffer in IRC NAT helper</title>
<updated>2014-01-15T23:28:53+00:00</updated>
<author>
<name>Daniel Borkmann</name>
<email>dborkman@redhat.com</email>
</author>
<published>2013-12-31T15:28:39+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=7b2252e993e29974eb0d017156db989173ec31aa'/>
<id>7b2252e993e29974eb0d017156db989173ec31aa</id>
<content type='text'>
commit 2690d97ade05c5325cbf7c72b94b90d265659886 upstream.

Commit 5901b6be885e attempted to introduce IPv6 support into
IRC NAT helper. By doing so, the following code seemed to be removed
by accident:

  ip = ntohl(exp-&gt;master-&gt;tuplehash[IP_CT_DIR_REPLY].tuple.dst.u3.ip);
  sprintf(buffer, "%u %u", ip, port);
  pr_debug("nf_nat_irc: inserting '%s' == %pI4, port %u\n", buffer, &amp;ip, port);

This leads to the fact that buffer[] was left uninitialized and
contained some stack value. When we call nf_nat_mangle_tcp_packet(),
we call strlen(buffer) on excatly this uninitialized buffer. If we
are unlucky and the skb has enough tailroom, we overwrite resp. leak
contents with values that sit on our stack into the packet and send
that out to the receiver.

Since the rather informal DCC spec [1] does not seem to specify
IPv6 support right now, we log such occurences so that admins can
act accordingly, and drop the packet. I've looked into XChat source,
and IPv6 is not supported there: addresses are in u32 and print
via %u format string.

Therefore, restore old behaviour as in IPv4, use snprintf(). The
IRC helper does not support IPv6 by now. By this, we can safely use
strlen(buffer) in nf_nat_mangle_tcp_packet() and prevent a buffer
overflow. Also simplify some code as we now have ct variable anyway.

  [1] http://www.irchelp.org/irchelp/rfc/ctcpspec.html

Fixes: 5901b6be885e ("netfilter: nf_nat: support IPv6 in IRC NAT helper")
Signed-off-by: Daniel Borkmann &lt;dborkman@redhat.com&gt;
Cc: Harald Welte &lt;laforge@gnumonks.org&gt;
Signed-off-by: Pablo Neira Ayuso &lt;pablo@netfilter.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 2690d97ade05c5325cbf7c72b94b90d265659886 upstream.

Commit 5901b6be885e attempted to introduce IPv6 support into
IRC NAT helper. By doing so, the following code seemed to be removed
by accident:

  ip = ntohl(exp-&gt;master-&gt;tuplehash[IP_CT_DIR_REPLY].tuple.dst.u3.ip);
  sprintf(buffer, "%u %u", ip, port);
  pr_debug("nf_nat_irc: inserting '%s' == %pI4, port %u\n", buffer, &amp;ip, port);

This leads to the fact that buffer[] was left uninitialized and
contained some stack value. When we call nf_nat_mangle_tcp_packet(),
we call strlen(buffer) on excatly this uninitialized buffer. If we
are unlucky and the skb has enough tailroom, we overwrite resp. leak
contents with values that sit on our stack into the packet and send
that out to the receiver.

Since the rather informal DCC spec [1] does not seem to specify
IPv6 support right now, we log such occurences so that admins can
act accordingly, and drop the packet. I've looked into XChat source,
and IPv6 is not supported there: addresses are in u32 and print
via %u format string.

Therefore, restore old behaviour as in IPv4, use snprintf(). The
IRC helper does not support IPv6 by now. By this, we can safely use
strlen(buffer) in nf_nat_mangle_tcp_packet() and prevent a buffer
overflow. Also simplify some code as we now have ct variable anyway.

  [1] http://www.irchelp.org/irchelp/rfc/ctcpspec.html

Fixes: 5901b6be885e ("netfilter: nf_nat: support IPv6 in IRC NAT helper")
Signed-off-by: Daniel Borkmann &lt;dborkman@redhat.com&gt;
Cc: Harald Welte &lt;laforge@gnumonks.org&gt;
Signed-off-by: Pablo Neira Ayuso &lt;pablo@netfilter.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
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