<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux.git/net/netfilter, branch v4.13</title>
<subtitle>Linux kernel source tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/'/>
<entry>
<title>Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf</title>
<updated>2017-08-24T18:49:19+00:00</updated>
<author>
<name>David S. Miller</name>
<email>davem@davemloft.net</email>
</author>
<published>2017-08-24T18:49:19+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=af57d2b720252baca5421ec58628da626e1862dc'/>
<id>af57d2b720252baca5421ec58628da626e1862dc</id>
<content type='text'>
Pablo Neira Ayuso says:

====================
Netfilter fixes for net

The following patchset contains Netfilter fixes for your net tree,
they are:

1) Fix use after free of struct proc_dir_entry in ipt_CLUSTERIP, patch
   from Sabrina Dubroca.

2) Fix spurious EINVAL errors from iptables over nft compatibility layer.

3) Reload pointer to ip header only if there is non-terminal verdict,
   ie. XT_CONTINUE, otherwise invalid memory access may happen, patch
   from Taehee Yoo.

4) Fix interaction between SYNPROXY and NAT, SYNPROXY adds sequence
   adjustment already, however from nf_nat_setup() assumes there's not.
   Patch from Xin Long.

5) Fix burst arithmetics in nft_limit as Joe Stringer mentioned during
   NFWS in Faro. Patch from Andy Zhou.
====================

Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pablo Neira Ayuso says:

====================
Netfilter fixes for net

The following patchset contains Netfilter fixes for your net tree,
they are:

1) Fix use after free of struct proc_dir_entry in ipt_CLUSTERIP, patch
   from Sabrina Dubroca.

2) Fix spurious EINVAL errors from iptables over nft compatibility layer.

3) Reload pointer to ip header only if there is non-terminal verdict,
   ie. XT_CONTINUE, otherwise invalid memory access may happen, patch
   from Taehee Yoo.

4) Fix interaction between SYNPROXY and NAT, SYNPROXY adds sequence
   adjustment already, however from nf_nat_setup() assumes there's not.
   Patch from Xin Long.

5) Fix burst arithmetics in nft_limit as Joe Stringer mentioned during
   NFWS in Faro. Patch from Andy Zhou.
====================

Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>netfilter: nf_tables: Fix nft limit burst handling</title>
<updated>2017-08-24T14:23:17+00:00</updated>
<author>
<name>andy zhou</name>
<email>azhou@ovn.org</email>
</author>
<published>2017-08-21T19:38:53+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=c26844eda9d4fdbd266660e3b3de2d0270e3a1ed'/>
<id>c26844eda9d4fdbd266660e3b3de2d0270e3a1ed</id>
<content type='text'>
Current implementation treats the burst configuration the same as
rate configuration. This can cause the per packet cost to be lower
than configured. In effect, this bug causes the token bucket to be
refilled at a higher rate than what user has specified.

This patch changes the implementation so that the token bucket size
is controlled by "rate + burst", while maintain the token bucket
refill rate the same as user specified.

Fixes: 96518518cc41 ("netfilter: add nftables")
Signed-off-by: Andy Zhou &lt;azhou@ovn.org&gt;
Acked-by: Joe Stringer &lt;joe@ovn.org&gt;
Signed-off-by: Pablo Neira Ayuso &lt;pablo@netfilter.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Current implementation treats the burst configuration the same as
rate configuration. This can cause the per packet cost to be lower
than configured. In effect, this bug causes the token bucket to be
refilled at a higher rate than what user has specified.

This patch changes the implementation so that the token bucket size
is controlled by "rate + burst", while maintain the token bucket
refill rate the same as user specified.

Fixes: 96518518cc41 ("netfilter: add nftables")
Signed-off-by: Andy Zhou &lt;azhou@ovn.org&gt;
Acked-by: Joe Stringer &lt;joe@ovn.org&gt;
Signed-off-by: Pablo Neira Ayuso &lt;pablo@netfilter.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>netfilter: check for seqadj ext existence before adding it in nf_nat_setup_info</title>
<updated>2017-08-24T14:09:03+00:00</updated>
<author>
<name>Xin Long</name>
<email>lucien.xin@gmail.com</email>
</author>
<published>2017-08-10T02:22:24+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=ab6dd1beac7be3c17f8bf3d38bdf29ecb7293f1e'/>
<id>ab6dd1beac7be3c17f8bf3d38bdf29ecb7293f1e</id>
<content type='text'>
Commit 4440a2ab3b9f ("netfilter: synproxy: Check oom when adding synproxy
and seqadj ct extensions") wanted to drop the packet when it fails to add
seqadj ext due to no memory by checking if nfct_seqadj_ext_add returns
NULL.

But that nfct_seqadj_ext_add returns NULL can also happen when seqadj ext
already exists in a nf_conn. It will cause that userspace protocol doesn't
work when both dnat and snat are configured.

Li Shuang found this issue in the case:

Topo:
   ftp client                   router                  ftp server
  10.167.131.2  &lt;-&gt; 10.167.131.254  10.167.141.254 &lt;-&gt; 10.167.141.1

Rules:
  # iptables -t nat -A PREROUTING -i eth1 -p tcp -m tcp --dport 21 -j \
    DNAT --to-destination 10.167.141.1
  # iptables -t nat -A POSTROUTING -o eth2 -p tcp -m tcp --dport 21 -j \
    SNAT --to-source 10.167.141.254

In router, when both dnat and snat are added, nf_nat_setup_info will be
called twice. The packet can be dropped at the 2nd time for DNAT due to
seqadj ext is already added at the 1st time for SNAT.

This patch is to fix it by checking for seqadj ext existence before adding
it, so that the packet will not be dropped if seqadj ext already exists.

Note that as Florian mentioned, as a long term, we should review ext_add()
behaviour, it's better to return a pointer to the existing ext instead.

Fixes: 4440a2ab3b9f ("netfilter: synproxy: Check oom when adding synproxy and seqadj ct extensions")
Reported-by: Li Shuang &lt;shuali@redhat.com&gt;
Acked-by: Florian Westphal &lt;fw@strlen.de&gt;
Signed-off-by: Xin Long &lt;lucien.xin@gmail.com&gt;
Signed-off-by: Pablo Neira Ayuso &lt;pablo@netfilter.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Commit 4440a2ab3b9f ("netfilter: synproxy: Check oom when adding synproxy
and seqadj ct extensions") wanted to drop the packet when it fails to add
seqadj ext due to no memory by checking if nfct_seqadj_ext_add returns
NULL.

But that nfct_seqadj_ext_add returns NULL can also happen when seqadj ext
already exists in a nf_conn. It will cause that userspace protocol doesn't
work when both dnat and snat are configured.

Li Shuang found this issue in the case:

Topo:
   ftp client                   router                  ftp server
  10.167.131.2  &lt;-&gt; 10.167.131.254  10.167.141.254 &lt;-&gt; 10.167.141.1

Rules:
  # iptables -t nat -A PREROUTING -i eth1 -p tcp -m tcp --dport 21 -j \
    DNAT --to-destination 10.167.141.1
  # iptables -t nat -A POSTROUTING -o eth2 -p tcp -m tcp --dport 21 -j \
    SNAT --to-source 10.167.141.254

In router, when both dnat and snat are added, nf_nat_setup_info will be
called twice. The packet can be dropped at the 2nd time for DNAT due to
seqadj ext is already added at the 1st time for SNAT.

This patch is to fix it by checking for seqadj ext existence before adding
it, so that the packet will not be dropped if seqadj ext already exists.

Note that as Florian mentioned, as a long term, we should review ext_add()
behaviour, it's better to return a pointer to the existing ext instead.

Fixes: 4440a2ab3b9f ("netfilter: synproxy: Check oom when adding synproxy and seqadj ct extensions")
Reported-by: Li Shuang &lt;shuali@redhat.com&gt;
Acked-by: Florian Westphal &lt;fw@strlen.de&gt;
Signed-off-by: Xin Long &lt;lucien.xin@gmail.com&gt;
Signed-off-by: Pablo Neira Ayuso &lt;pablo@netfilter.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net</title>
<updated>2017-07-20T23:33:39+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2017-07-20T23:33:39+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=96080f697786e0a30006fcbcc5b53f350fcb3e9f'/>
<id>96080f697786e0a30006fcbcc5b53f350fcb3e9f</id>
<content type='text'>
Pull networking fixes from David Miller:

 1) BPF verifier signed/unsigned value tracking fix, from Daniel
    Borkmann, Edward Cree, and Josef Bacik.

 2) Fix memory allocation length when setting up calls to
    -&gt;ndo_set_mac_address, from Cong Wang.

 3) Add a new cxgb4 device ID, from Ganesh Goudar.

 4) Fix FIB refcount handling, we have to set it's initial value before
    the configure callback (which can bump it). From David Ahern.

 5) Fix double-free in qcom/emac driver, from Timur Tabi.

 6) A bunch of gcc-7 string format overflow warning fixes from Arnd
    Bergmann.

 7) Fix link level headroom tests in ip_do_fragment(), from Vasily
    Averin.

 8) Fix chunk walking in SCTP when iterating over error and parameter
    headers. From Alexander Potapenko.

 9) TCP BBR congestion control fixes from Neal Cardwell.

10) Fix SKB fragment handling in bcmgenet driver, from Doug Berger.

11) BPF_CGROUP_RUN_PROG_SOCK_OPS needs to check for null __sk, from Cong
    Wang.

12) xmit_recursion in ppp driver needs to be per-device not per-cpu,
    from Gao Feng.

13) Cannot release skb-&gt;dst in UDP if IP options processing needs it.
    From Paolo Abeni.

14) Some netdev ioctl ifr_name[] NULL termination fixes. From Alexander
    Levin and myself.

15) Revert some rtnetlink notification changes that are causing
    regressions, from David Ahern.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (83 commits)
  net: bonding: Fix transmit load balancing in balance-alb mode
  rds: Make sure updates to cp_send_gen can be observed
  net: ethernet: ti: cpsw: Push the request_irq function to the end of probe
  ipv4: initialize fib_trie prior to register_netdev_notifier call.
  rtnetlink: allocate more memory for dev_set_mac_address()
  net: dsa: b53: Add missing ARL entries for BCM53125
  bpf: more tests for mixed signed and unsigned bounds checks
  bpf: add test for mixed signed and unsigned bounds checks
  bpf: fix up test cases with mixed signed/unsigned bounds
  bpf: allow to specify log level and reduce it for test_verifier
  bpf: fix mixed signed/unsigned derived min/max value bounds
  ipv6: avoid overflow of offset in ip6_find_1stfragopt
  net: tehuti: don't process data if it has not been copied from userspace
  Revert "rtnetlink: Do not generate notifications for CHANGEADDR event"
  net: dsa: mv88e6xxx: Enable CMODE config support for 6390X
  dt-binding: ptp: Add SoC compatibility strings for dte ptp clock
  NET: dwmac: Make dwmac reset unconditional
  net: Zero terminate ifr_name in dev_ifname().
  wireless: wext: terminate ifr name coming from userspace
  netfilter: fix netfilter_net_init() return
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull networking fixes from David Miller:

 1) BPF verifier signed/unsigned value tracking fix, from Daniel
    Borkmann, Edward Cree, and Josef Bacik.

 2) Fix memory allocation length when setting up calls to
    -&gt;ndo_set_mac_address, from Cong Wang.

 3) Add a new cxgb4 device ID, from Ganesh Goudar.

 4) Fix FIB refcount handling, we have to set it's initial value before
    the configure callback (which can bump it). From David Ahern.

 5) Fix double-free in qcom/emac driver, from Timur Tabi.

 6) A bunch of gcc-7 string format overflow warning fixes from Arnd
    Bergmann.

 7) Fix link level headroom tests in ip_do_fragment(), from Vasily
    Averin.

 8) Fix chunk walking in SCTP when iterating over error and parameter
    headers. From Alexander Potapenko.

 9) TCP BBR congestion control fixes from Neal Cardwell.

10) Fix SKB fragment handling in bcmgenet driver, from Doug Berger.

11) BPF_CGROUP_RUN_PROG_SOCK_OPS needs to check for null __sk, from Cong
    Wang.

12) xmit_recursion in ppp driver needs to be per-device not per-cpu,
    from Gao Feng.

13) Cannot release skb-&gt;dst in UDP if IP options processing needs it.
    From Paolo Abeni.

14) Some netdev ioctl ifr_name[] NULL termination fixes. From Alexander
    Levin and myself.

15) Revert some rtnetlink notification changes that are causing
    regressions, from David Ahern.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (83 commits)
  net: bonding: Fix transmit load balancing in balance-alb mode
  rds: Make sure updates to cp_send_gen can be observed
  net: ethernet: ti: cpsw: Push the request_irq function to the end of probe
  ipv4: initialize fib_trie prior to register_netdev_notifier call.
  rtnetlink: allocate more memory for dev_set_mac_address()
  net: dsa: b53: Add missing ARL entries for BCM53125
  bpf: more tests for mixed signed and unsigned bounds checks
  bpf: add test for mixed signed and unsigned bounds checks
  bpf: fix up test cases with mixed signed/unsigned bounds
  bpf: allow to specify log level and reduce it for test_verifier
  bpf: fix mixed signed/unsigned derived min/max value bounds
  ipv6: avoid overflow of offset in ip6_find_1stfragopt
  net: tehuti: don't process data if it has not been copied from userspace
  Revert "rtnetlink: Do not generate notifications for CHANGEADDR event"
  net: dsa: mv88e6xxx: Enable CMODE config support for 6390X
  dt-binding: ptp: Add SoC compatibility strings for dte ptp clock
  NET: dwmac: Make dwmac reset unconditional
  net: Zero terminate ifr_name in dev_ifname().
  wireless: wext: terminate ifr name coming from userspace
  netfilter: fix netfilter_net_init() return
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>netfilter: nft_compat: check extension hook mask only if set</title>
<updated>2017-07-19T09:53:30+00:00</updated>
<author>
<name>Pablo Neira Ayuso</name>
<email>pablo@netfilter.org</email>
</author>
<published>2017-07-18T18:03:05+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=f7fb77fc12352d15180dc3c08ffba10573d5167d'/>
<id>f7fb77fc12352d15180dc3c08ffba10573d5167d</id>
<content type='text'>
If the x_tables extension comes with no hook mask, skip this validation.

Signed-off-by: Pablo Neira Ayuso &lt;pablo@netfilter.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
If the x_tables extension comes with no hook mask, skip this validation.

Signed-off-by: Pablo Neira Ayuso &lt;pablo@netfilter.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>netfilter: fix netfilter_net_init() return</title>
<updated>2017-07-18T21:50:28+00:00</updated>
<author>
<name>Dan Carpenter</name>
<email>dan.carpenter@oracle.com</email>
</author>
<published>2017-07-18T19:38:56+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=073dd5ad34b1d3aaadaa7e5e8cbe576d9545f163'/>
<id>073dd5ad34b1d3aaadaa7e5e8cbe576d9545f163</id>
<content type='text'>
We accidentally return an uninitialized variable.

Fixes: cf56c2f892a8 ("netfilter: remove old pre-netns era hook api")
Signed-off-by: Dan Carpenter &lt;dan.carpenter@oracle.com&gt;
Acked-by: Pablo Neira Ayuso &lt;pablo@netfilter.org&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
We accidentally return an uninitialized variable.

Fixes: cf56c2f892a8 ("netfilter: remove old pre-netns era hook api")
Signed-off-by: Dan Carpenter &lt;dan.carpenter@oracle.com&gt;
Acked-by: Pablo Neira Ayuso &lt;pablo@netfilter.org&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>netfilter: expect: fix crash when putting uninited expectation</title>
<updated>2017-07-17T15:03:12+00:00</updated>
<author>
<name>Florian Westphal</name>
<email>fw@strlen.de</email>
</author>
<published>2017-07-10T11:53:53+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=36ac344e16e04e3e55e8fed7446095a6458c64e6'/>
<id>36ac344e16e04e3e55e8fed7446095a6458c64e6</id>
<content type='text'>
We crash in __nf_ct_expect_check, it calls nf_ct_remove_expect on the
uninitialised expectation instead of existing one, so del_timer chokes
on random memory address.

Fixes: ec0e3f01114ad32711243 ("netfilter: nf_ct_expect: Add nf_ct_remove_expect()")
Reported-by: Sergey Kvachonok &lt;ravenexp@gmail.com&gt;
Tested-by: Sergey Kvachonok &lt;ravenexp@gmail.com&gt;
Cc: Gao Feng &lt;fgao@ikuai8.com&gt;
Signed-off-by: Florian Westphal &lt;fw@strlen.de&gt;
Signed-off-by: Pablo Neira Ayuso &lt;pablo@netfilter.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
We crash in __nf_ct_expect_check, it calls nf_ct_remove_expect on the
uninitialised expectation instead of existing one, so del_timer chokes
on random memory address.

Fixes: ec0e3f01114ad32711243 ("netfilter: nf_ct_expect: Add nf_ct_remove_expect()")
Reported-by: Sergey Kvachonok &lt;ravenexp@gmail.com&gt;
Tested-by: Sergey Kvachonok &lt;ravenexp@gmail.com&gt;
Cc: Gao Feng &lt;fgao@ikuai8.com&gt;
Signed-off-by: Florian Westphal &lt;fw@strlen.de&gt;
Signed-off-by: Pablo Neira Ayuso &lt;pablo@netfilter.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>netfilter: nat: fix src map lookup</title>
<updated>2017-07-17T15:02:19+00:00</updated>
<author>
<name>Florian Westphal</name>
<email>fw@strlen.de</email>
</author>
<published>2017-07-07T11:07:17+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=97772bcd56efa21d9d8976db6f205574ea602f51'/>
<id>97772bcd56efa21d9d8976db6f205574ea602f51</id>
<content type='text'>
When doing initial conversion to rhashtable I replaced the bucket
walk with a single rhashtable_lookup_fast().

When moving to rhlist I failed to properly walk the list of identical
tuples, but that is what is needed for this to work correctly.
The table contains the original tuples, so the reply tuples are all
distinct.

We currently decide that mapping is (not) in range only based on the
first entry, but in case its not we need to try the reply tuple of the
next entry until we either find an in-range mapping or we checked
all the entries.

This bug makes nat core attempt collision resolution while it might be
able to use the mapping as-is.

Fixes: 870190a9ec90 ("netfilter: nat: convert nat bysrc hash to rhashtable")
Reported-by: Jaco Kroon &lt;jaco@uls.co.za&gt;
Tested-by: Jaco Kroon &lt;jaco@uls.co.za&gt;
Signed-off-by: Florian Westphal &lt;fw@strlen.de&gt;
Signed-off-by: Pablo Neira Ayuso &lt;pablo@netfilter.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
When doing initial conversion to rhashtable I replaced the bucket
walk with a single rhashtable_lookup_fast().

When moving to rhlist I failed to properly walk the list of identical
tuples, but that is what is needed for this to work correctly.
The table contains the original tuples, so the reply tuples are all
distinct.

We currently decide that mapping is (not) in range only based on the
first entry, but in case its not we need to try the reply tuple of the
next entry until we either find an in-range mapping or we checked
all the entries.

This bug makes nat core attempt collision resolution while it might be
able to use the mapping as-is.

Fixes: 870190a9ec90 ("netfilter: nat: convert nat bysrc hash to rhashtable")
Reported-by: Jaco Kroon &lt;jaco@uls.co.za&gt;
Tested-by: Jaco Kroon &lt;jaco@uls.co.za&gt;
Signed-off-by: Florian Westphal &lt;fw@strlen.de&gt;
Signed-off-by: Pablo Neira Ayuso &lt;pablo@netfilter.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>netfilter: remove old pre-netns era hook api</title>
<updated>2017-07-17T15:01:10+00:00</updated>
<author>
<name>Florian Westphal</name>
<email>fw@strlen.de</email>
</author>
<published>2017-07-06T21:17:44+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=cf56c2f892a8a1870a8358114ad896772da7543a'/>
<id>cf56c2f892a8a1870a8358114ad896772da7543a</id>
<content type='text'>
no more users in the tree, remove this.

The old api is racy wrt. module removal, all users have been converted
to the netns-aware api.

The old api pretended we still have global hooks but that has not been
true for a long time.

Signed-off-by: Florian Westphal &lt;fw@strlen.de&gt;
Signed-off-by: Pablo Neira Ayuso &lt;pablo@netfilter.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
no more users in the tree, remove this.

The old api is racy wrt. module removal, all users have been converted
to the netns-aware api.

The old api pretended we still have global hooks but that has not been
true for a long time.

Signed-off-by: Florian Westphal &lt;fw@strlen.de&gt;
Signed-off-by: Pablo Neira Ayuso &lt;pablo@netfilter.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>netfilter: nfnetlink: Improve input length sanitization in nfnetlink_rcv</title>
<updated>2017-07-17T11:27:46+00:00</updated>
<author>
<name>Mateusz Jurczyk</name>
<email>mjurczyk@google.com</email>
</author>
<published>2017-06-07T13:50:38+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=f55ce7b024090a51382ccab2730b96e2f7b4e9cf'/>
<id>f55ce7b024090a51382ccab2730b96e2f7b4e9cf</id>
<content type='text'>
Verify that the length of the socket buffer is sufficient to cover the
nlmsghdr structure before accessing the nlh-&gt;nlmsg_len field for further
input sanitization. If the client only supplies 1-3 bytes of data in
sk_buff, then nlh-&gt;nlmsg_len remains partially uninitialized and
contains leftover memory from the corresponding kernel allocation.
Operating on such data may result in indeterminate evaluation of the
nlmsg_len &lt; NLMSG_HDRLEN expression.

The bug was discovered by a runtime instrumentation designed to detect
use of uninitialized memory in the kernel. The patch prevents this and
other similar tools (e.g. KMSAN) from flagging this behavior in the future.

Signed-off-by: Mateusz Jurczyk &lt;mjurczyk@google.com&gt;
Signed-off-by: Pablo Neira Ayuso &lt;pablo@netfilter.org&gt;
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<pre>
Verify that the length of the socket buffer is sufficient to cover the
nlmsghdr structure before accessing the nlh-&gt;nlmsg_len field for further
input sanitization. If the client only supplies 1-3 bytes of data in
sk_buff, then nlh-&gt;nlmsg_len remains partially uninitialized and
contains leftover memory from the corresponding kernel allocation.
Operating on such data may result in indeterminate evaluation of the
nlmsg_len &lt; NLMSG_HDRLEN expression.

The bug was discovered by a runtime instrumentation designed to detect
use of uninitialized memory in the kernel. The patch prevents this and
other similar tools (e.g. KMSAN) from flagging this behavior in the future.

Signed-off-by: Mateusz Jurczyk &lt;mjurczyk@google.com&gt;
Signed-off-by: Pablo Neira Ayuso &lt;pablo@netfilter.org&gt;
</pre>
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</content>
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