<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/drivers/net/macsec.c, branch v5.4</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>net: remove unnecessary variables and callback</title>
<updated>2019-10-24T21:53:49+00:00</updated>
<author>
<name>Taehee Yoo</name>
<email>ap420073@gmail.com</email>
</author>
<published>2019-10-21T18:47:58+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=f3b0a18bb6cb07a9abb75e21b1f08eeaefa78e81'/>
<id>f3b0a18bb6cb07a9abb75e21b1f08eeaefa78e81</id>
<content type='text'>
This patch removes variables and callback these are related to the nested
device structure.
devices that can be nested have their own nest_level variable that
represents the depth of nested devices.
In the previous patch, new {lower/upper}_level variables are added and
they replace old private nest_level variable.
So, this patch removes all 'nest_level' variables.

In order to avoid lockdep warning, -&gt;ndo_get_lock_subclass() was added
to get lockdep subclass value, which is actually lower nested depth value.
But now, they use the dynamic lockdep key to avoid lockdep warning instead
of the subclass.
So, this patch removes -&gt;ndo_get_lock_subclass() callback.

Signed-off-by: Taehee Yoo &lt;ap420073@gmail.com&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>
This patch removes variables and callback these are related to the nested
device structure.
devices that can be nested have their own nest_level variable that
represents the depth of nested devices.
In the previous patch, new {lower/upper}_level variables are added and
they replace old private nest_level variable.
So, this patch removes all 'nest_level' variables.

In order to avoid lockdep warning, -&gt;ndo_get_lock_subclass() was added
to get lockdep subclass value, which is actually lower nested depth value.
But now, they use the dynamic lockdep key to avoid lockdep warning instead
of the subclass.
So, this patch removes -&gt;ndo_get_lock_subclass() callback.

Signed-off-by: Taehee Yoo &lt;ap420073@gmail.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>macsec: fix refcnt leak in module exit routine</title>
<updated>2019-10-24T21:53:48+00:00</updated>
<author>
<name>Taehee Yoo</name>
<email>ap420073@gmail.com</email>
</author>
<published>2019-10-21T18:47:55+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=2bce1ebed17da54c65042ec2b962e3234bad5b47'/>
<id>2bce1ebed17da54c65042ec2b962e3234bad5b47</id>
<content type='text'>
When a macsec interface is created, it increases a refcnt to a lower
device(real device). when macsec interface is deleted, the refcnt is
decreased in macsec_free_netdev(), which is -&gt;priv_destructor() of
macsec interface.

The problem scenario is this.
When nested macsec interfaces are exiting, the exit routine of the
macsec module makes refcnt leaks.

Test commands:
    ip link add dummy0 type dummy
    ip link add macsec0 link dummy0 type macsec
    ip link add macsec1 link macsec0 type macsec
    modprobe -rv macsec

[  208.629433] unregister_netdevice: waiting for macsec0 to become free. Usage count = 1

Steps of exit routine of macsec module are below.
1. Calls -&gt;dellink() in __rtnl_link_unregister().
2. Checks refcnt and wait refcnt to be 0 if refcnt is not 0 in
netdev_run_todo().
3. Calls -&gt;priv_destruvtor() in netdev_run_todo().

Step2 checks refcnt, but step3 decreases refcnt.
So, step2 waits forever.

This patch makes the macsec module do not hold a refcnt of the lower
device because it already holds a refcnt of the lower device with
netdev_upper_dev_link().

Fixes: c09440f7dcb3 ("macsec: introduce IEEE 802.1AE driver")
Signed-off-by: Taehee Yoo &lt;ap420073@gmail.com&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>
When a macsec interface is created, it increases a refcnt to a lower
device(real device). when macsec interface is deleted, the refcnt is
decreased in macsec_free_netdev(), which is -&gt;priv_destructor() of
macsec interface.

The problem scenario is this.
When nested macsec interfaces are exiting, the exit routine of the
macsec module makes refcnt leaks.

Test commands:
    ip link add dummy0 type dummy
    ip link add macsec0 link dummy0 type macsec
    ip link add macsec1 link macsec0 type macsec
    modprobe -rv macsec

[  208.629433] unregister_netdevice: waiting for macsec0 to become free. Usage count = 1

Steps of exit routine of macsec module are below.
1. Calls -&gt;dellink() in __rtnl_link_unregister().
2. Checks refcnt and wait refcnt to be 0 if refcnt is not 0 in
netdev_run_todo().
3. Calls -&gt;priv_destruvtor() in netdev_run_todo().

Step2 checks refcnt, but step3 decreases refcnt.
So, step2 waits forever.

This patch makes the macsec module do not hold a refcnt of the lower
device because it already holds a refcnt of the lower device with
netdev_upper_dev_link().

Fixes: c09440f7dcb3 ("macsec: introduce IEEE 802.1AE driver")
Signed-off-by: Taehee Yoo &lt;ap420073@gmail.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>net: core: add generic lockdep keys</title>
<updated>2019-10-24T21:53:48+00:00</updated>
<author>
<name>Taehee Yoo</name>
<email>ap420073@gmail.com</email>
</author>
<published>2019-10-21T18:47:51+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=ab92d68fc22f9afab480153bd82a20f6e2533769'/>
<id>ab92d68fc22f9afab480153bd82a20f6e2533769</id>
<content type='text'>
Some interface types could be nested.
(VLAN, BONDING, TEAM, MACSEC, MACVLAN, IPVLAN, VIRT_WIFI, VXLAN, etc..)
These interface types should set lockdep class because, without lockdep
class key, lockdep always warn about unexisting circular locking.

In the current code, these interfaces have their own lockdep class keys and
these manage itself. So that there are so many duplicate code around the
/driver/net and /net/.
This patch adds new generic lockdep keys and some helper functions for it.

This patch does below changes.
a) Add lockdep class keys in struct net_device
   - qdisc_running, xmit, addr_list, qdisc_busylock
   - these keys are used as dynamic lockdep key.
b) When net_device is being allocated, lockdep keys are registered.
   - alloc_netdev_mqs()
c) When net_device is being free'd llockdep keys are unregistered.
   - free_netdev()
d) Add generic lockdep key helper function
   - netdev_register_lockdep_key()
   - netdev_unregister_lockdep_key()
   - netdev_update_lockdep_key()
e) Remove unnecessary generic lockdep macro and functions
f) Remove unnecessary lockdep code of each interfaces.

After this patch, each interface modules don't need to maintain
their lockdep keys.

Signed-off-by: Taehee Yoo &lt;ap420073@gmail.com&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>
Some interface types could be nested.
(VLAN, BONDING, TEAM, MACSEC, MACVLAN, IPVLAN, VIRT_WIFI, VXLAN, etc..)
These interface types should set lockdep class because, without lockdep
class key, lockdep always warn about unexisting circular locking.

In the current code, these interfaces have their own lockdep class keys and
these manage itself. So that there are so many duplicate code around the
/driver/net and /net/.
This patch adds new generic lockdep keys and some helper functions for it.

This patch does below changes.
a) Add lockdep class keys in struct net_device
   - qdisc_running, xmit, addr_list, qdisc_busylock
   - these keys are used as dynamic lockdep key.
b) When net_device is being allocated, lockdep keys are registered.
   - alloc_netdev_mqs()
c) When net_device is being free'd llockdep keys are unregistered.
   - free_netdev()
d) Add generic lockdep key helper function
   - netdev_register_lockdep_key()
   - netdev_unregister_lockdep_key()
   - netdev_update_lockdep_key()
e) Remove unnecessary generic lockdep macro and functions
f) Remove unnecessary lockdep code of each interfaces.

After this patch, each interface modules don't need to maintain
their lockdep keys.

Signed-off-by: Taehee Yoo &lt;ap420073@gmail.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>macsec: drop skb sk before calling gro_cells_receive</title>
<updated>2019-09-26T07:25:03+00:00</updated>
<author>
<name>Xin Long</name>
<email>lucien.xin@gmail.com</email>
</author>
<published>2019-09-23T09:02:46+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=ba56d8ce38c8252fff5b745db3899cf092578ede'/>
<id>ba56d8ce38c8252fff5b745db3899cf092578ede</id>
<content type='text'>
Fei Liu reported a crash when doing netperf on a topo of macsec
dev over veth:

  [  448.919128] refcount_t: underflow; use-after-free.
  [  449.090460] Call trace:
  [  449.092895]  refcount_sub_and_test+0xb4/0xc0
  [  449.097155]  tcp_wfree+0x2c/0x150
  [  449.100460]  ip_rcv+0x1d4/0x3a8
  [  449.103591]  __netif_receive_skb_core+0x554/0xae0
  [  449.108282]  __netif_receive_skb+0x28/0x78
  [  449.112366]  netif_receive_skb_internal+0x54/0x100
  [  449.117144]  napi_gro_complete+0x70/0xc0
  [  449.121054]  napi_gro_flush+0x6c/0x90
  [  449.124703]  napi_complete_done+0x50/0x130
  [  449.128788]  gro_cell_poll+0x8c/0xa8
  [  449.132351]  net_rx_action+0x16c/0x3f8
  [  449.136088]  __do_softirq+0x128/0x320

The issue was caused by skb's true_size changed without its sk's
sk_wmem_alloc increased in tcp/skb_gro_receive(). Later when the
skb is being freed and the skb's truesize is subtracted from its
sk's sk_wmem_alloc in tcp_wfree(), underflow occurs.

macsec is calling gro_cells_receive() to receive a packet, which
actually requires skb-&gt;sk to be NULL. However when macsec dev is
over veth, it's possible the skb-&gt;sk is still set if the skb was
not unshared or expanded from the peer veth.

ip_rcv() is calling skb_orphan() to drop the skb's sk for tproxy,
but it is too late for macsec's calling gro_cells_receive(). So
fix it by dropping the skb's sk earlier on rx path of macsec.

Fixes: 5491e7c6b1a9 ("macsec: enable GRO and RPS on macsec devices")
Reported-by: Xiumei Mu &lt;xmu@redhat.com&gt;
Reported-by: Fei Liu &lt;feliu@redhat.com&gt;
Signed-off-by: Xin Long &lt;lucien.xin@gmail.com&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>
Fei Liu reported a crash when doing netperf on a topo of macsec
dev over veth:

  [  448.919128] refcount_t: underflow; use-after-free.
  [  449.090460] Call trace:
  [  449.092895]  refcount_sub_and_test+0xb4/0xc0
  [  449.097155]  tcp_wfree+0x2c/0x150
  [  449.100460]  ip_rcv+0x1d4/0x3a8
  [  449.103591]  __netif_receive_skb_core+0x554/0xae0
  [  449.108282]  __netif_receive_skb+0x28/0x78
  [  449.112366]  netif_receive_skb_internal+0x54/0x100
  [  449.117144]  napi_gro_complete+0x70/0xc0
  [  449.121054]  napi_gro_flush+0x6c/0x90
  [  449.124703]  napi_complete_done+0x50/0x130
  [  449.128788]  gro_cell_poll+0x8c/0xa8
  [  449.132351]  net_rx_action+0x16c/0x3f8
  [  449.136088]  __do_softirq+0x128/0x320

The issue was caused by skb's true_size changed without its sk's
sk_wmem_alloc increased in tcp/skb_gro_receive(). Later when the
skb is being freed and the skb's truesize is subtracted from its
sk's sk_wmem_alloc in tcp_wfree(), underflow occurs.

macsec is calling gro_cells_receive() to receive a packet, which
actually requires skb-&gt;sk to be NULL. However when macsec dev is
over veth, it's possible the skb-&gt;sk is still set if the skb was
not unshared or expanded from the peer veth.

ip_rcv() is calling skb_orphan() to drop the skb's sk for tproxy,
but it is too late for macsec's calling gro_cells_receive(). So
fix it by dropping the skb's sk earlier on rx path of macsec.

Fixes: 5491e7c6b1a9 ("macsec: enable GRO and RPS on macsec devices")
Reported-by: Xiumei Mu &lt;xmu@redhat.com&gt;
Reported-by: Fei Liu &lt;feliu@redhat.com&gt;
Signed-off-by: Xin Long &lt;lucien.xin@gmail.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>macsec: fix checksumming after decryption</title>
<updated>2019-07-02T21:12:29+00:00</updated>
<author>
<name>Andreas Steinmetz</name>
<email>ast@domdv.de</email>
</author>
<published>2019-06-30T20:46:45+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=7d8b16b9facb0dd81d1469808dd9a575fa1d525a'/>
<id>7d8b16b9facb0dd81d1469808dd9a575fa1d525a</id>
<content type='text'>
Fix checksumming after decryption.

Signed-off-by: Andreas Steinmetz &lt;ast@domdv.de&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>
Fix checksumming after decryption.

Signed-off-by: Andreas Steinmetz &lt;ast@domdv.de&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>macsec: fix use-after-free of skb during RX</title>
<updated>2019-07-02T21:12:29+00:00</updated>
<author>
<name>Andreas Steinmetz</name>
<email>ast@domdv.de</email>
</author>
<published>2019-06-30T20:46:42+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=095c02da80a41cf6d311c504d8955d6d1c2add10'/>
<id>095c02da80a41cf6d311c504d8955d6d1c2add10</id>
<content type='text'>
Fix use-after-free of skb when rx_handler returns RX_HANDLER_PASS.

Signed-off-by: Andreas Steinmetz &lt;ast@domdv.de&gt;
Acked-by: Willem de Bruijn &lt;willemb@google.com&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>
Fix use-after-free of skb when rx_handler returns RX_HANDLER_PASS.

Signed-off-by: Andreas Steinmetz &lt;ast@domdv.de&gt;
Acked-by: Willem de Bruijn &lt;willemb@google.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152</title>
<updated>2019-05-30T18:26:32+00:00</updated>
<author>
<name>Thomas Gleixner</name>
<email>tglx@linutronix.de</email>
</author>
<published>2019-05-27T06:55:01+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=2874c5fd284268364ece81a7bd936f3c8168e567'/>
<id>2874c5fd284268364ece81a7bd936f3c8168e567</id>
<content type='text'>
Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license as published by
  the free software foundation either version 2 of the license or at
  your option any later version

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 3029 file(s).

Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Reviewed-by: Allison Randal &lt;allison@lohutok.net&gt;
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license as published by
  the free software foundation either version 2 of the license or at
  your option any later version

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 3029 file(s).

Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Reviewed-by: Allison Randal &lt;allison@lohutok.net&gt;
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>genetlink: optionally validate strictly/dumps</title>
<updated>2019-04-27T21:07:22+00:00</updated>
<author>
<name>Johannes Berg</name>
<email>johannes.berg@intel.com</email>
</author>
<published>2019-04-26T12:07:31+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=ef6243acb4782df587a4d7d6c310fa5b5d82684b'/>
<id>ef6243acb4782df587a4d7d6c310fa5b5d82684b</id>
<content type='text'>
Add options to strictly validate messages and dump messages,
sometimes perhaps validating dump messages non-strictly may
be required, so add an option for that as well.

Since none of this can really be applied to existing commands,
set the options everwhere using the following spatch:

    @@
    identifier ops;
    expression X;
    @@
    struct genl_ops ops[] = {
    ...,
     {
            .cmd = X,
    +       .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
            ...
     },
    ...
    };

For new commands one should just not copy the .validate 'opt-out'
flags and thus get strict validation.

Signed-off-by: Johannes Berg &lt;johannes.berg@intel.com&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>
Add options to strictly validate messages and dump messages,
sometimes perhaps validating dump messages non-strictly may
be required, so add an option for that as well.

Since none of this can really be applied to existing commands,
set the options everwhere using the following spatch:

    @@
    identifier ops;
    expression X;
    @@
    struct genl_ops ops[] = {
    ...,
     {
            .cmd = X,
    +       .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
            ...
     },
    ...
    };

For new commands one should just not copy the .validate 'opt-out'
flags and thus get strict validation.

Signed-off-by: Johannes Berg &lt;johannes.berg@intel.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>netlink: make validation more configurable for future strictness</title>
<updated>2019-04-27T21:07:21+00:00</updated>
<author>
<name>Johannes Berg</name>
<email>johannes.berg@intel.com</email>
</author>
<published>2019-04-26T12:07:28+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=8cb081746c031fb164089322e2336a0bf5b3070c'/>
<id>8cb081746c031fb164089322e2336a0bf5b3070c</id>
<content type='text'>
We currently have two levels of strict validation:

 1) liberal (default)
     - undefined (type &gt;= max) &amp; NLA_UNSPEC attributes accepted
     - attribute length &gt;= expected accepted
     - garbage at end of message accepted
 2) strict (opt-in)
     - NLA_UNSPEC attributes accepted
     - attribute length &gt;= expected accepted

Split out parsing strictness into four different options:
 * TRAILING     - check that there's no trailing data after parsing
                  attributes (in message or nested)
 * MAXTYPE      - reject attrs &gt; max known type
 * UNSPEC       - reject attributes with NLA_UNSPEC policy entries
 * STRICT_ATTRS - strictly validate attribute size

The default for future things should be *everything*.
The current *_strict() is a combination of TRAILING and MAXTYPE,
and is renamed to _deprecated_strict().
The current regular parsing has none of this, and is renamed to
*_parse_deprecated().

Additionally it allows us to selectively set one of the new flags
even on old policies. Notably, the UNSPEC flag could be useful in
this case, since it can be arranged (by filling in the policy) to
not be an incompatible userspace ABI change, but would then going
forward prevent forgetting attribute entries. Similar can apply
to the POLICY flag.

We end up with the following renames:
 * nla_parse           -&gt; nla_parse_deprecated
 * nla_parse_strict    -&gt; nla_parse_deprecated_strict
 * nlmsg_parse         -&gt; nlmsg_parse_deprecated
 * nlmsg_parse_strict  -&gt; nlmsg_parse_deprecated_strict
 * nla_parse_nested    -&gt; nla_parse_nested_deprecated
 * nla_validate_nested -&gt; nla_validate_nested_deprecated

Using spatch, of course:
    @@
    expression TB, MAX, HEAD, LEN, POL, EXT;
    @@
    -nla_parse(TB, MAX, HEAD, LEN, POL, EXT)
    +nla_parse_deprecated(TB, MAX, HEAD, LEN, POL, EXT)

    @@
    expression NLH, HDRLEN, TB, MAX, POL, EXT;
    @@
    -nlmsg_parse(NLH, HDRLEN, TB, MAX, POL, EXT)
    +nlmsg_parse_deprecated(NLH, HDRLEN, TB, MAX, POL, EXT)

    @@
    expression NLH, HDRLEN, TB, MAX, POL, EXT;
    @@
    -nlmsg_parse_strict(NLH, HDRLEN, TB, MAX, POL, EXT)
    +nlmsg_parse_deprecated_strict(NLH, HDRLEN, TB, MAX, POL, EXT)

    @@
    expression TB, MAX, NLA, POL, EXT;
    @@
    -nla_parse_nested(TB, MAX, NLA, POL, EXT)
    +nla_parse_nested_deprecated(TB, MAX, NLA, POL, EXT)

    @@
    expression START, MAX, POL, EXT;
    @@
    -nla_validate_nested(START, MAX, POL, EXT)
    +nla_validate_nested_deprecated(START, MAX, POL, EXT)

    @@
    expression NLH, HDRLEN, MAX, POL, EXT;
    @@
    -nlmsg_validate(NLH, HDRLEN, MAX, POL, EXT)
    +nlmsg_validate_deprecated(NLH, HDRLEN, MAX, POL, EXT)

For this patch, don't actually add the strict, non-renamed versions
yet so that it breaks compile if I get it wrong.

Also, while at it, make nla_validate and nla_parse go down to a
common __nla_validate_parse() function to avoid code duplication.

Ultimately, this allows us to have very strict validation for every
new caller of nla_parse()/nlmsg_parse() etc as re-introduced in the
next patch, while existing things will continue to work as is.

In effect then, this adds fully strict validation for any new command.

Signed-off-by: Johannes Berg &lt;johannes.berg@intel.com&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 currently have two levels of strict validation:

 1) liberal (default)
     - undefined (type &gt;= max) &amp; NLA_UNSPEC attributes accepted
     - attribute length &gt;= expected accepted
     - garbage at end of message accepted
 2) strict (opt-in)
     - NLA_UNSPEC attributes accepted
     - attribute length &gt;= expected accepted

Split out parsing strictness into four different options:
 * TRAILING     - check that there's no trailing data after parsing
                  attributes (in message or nested)
 * MAXTYPE      - reject attrs &gt; max known type
 * UNSPEC       - reject attributes with NLA_UNSPEC policy entries
 * STRICT_ATTRS - strictly validate attribute size

The default for future things should be *everything*.
The current *_strict() is a combination of TRAILING and MAXTYPE,
and is renamed to _deprecated_strict().
The current regular parsing has none of this, and is renamed to
*_parse_deprecated().

Additionally it allows us to selectively set one of the new flags
even on old policies. Notably, the UNSPEC flag could be useful in
this case, since it can be arranged (by filling in the policy) to
not be an incompatible userspace ABI change, but would then going
forward prevent forgetting attribute entries. Similar can apply
to the POLICY flag.

We end up with the following renames:
 * nla_parse           -&gt; nla_parse_deprecated
 * nla_parse_strict    -&gt; nla_parse_deprecated_strict
 * nlmsg_parse         -&gt; nlmsg_parse_deprecated
 * nlmsg_parse_strict  -&gt; nlmsg_parse_deprecated_strict
 * nla_parse_nested    -&gt; nla_parse_nested_deprecated
 * nla_validate_nested -&gt; nla_validate_nested_deprecated

Using spatch, of course:
    @@
    expression TB, MAX, HEAD, LEN, POL, EXT;
    @@
    -nla_parse(TB, MAX, HEAD, LEN, POL, EXT)
    +nla_parse_deprecated(TB, MAX, HEAD, LEN, POL, EXT)

    @@
    expression NLH, HDRLEN, TB, MAX, POL, EXT;
    @@
    -nlmsg_parse(NLH, HDRLEN, TB, MAX, POL, EXT)
    +nlmsg_parse_deprecated(NLH, HDRLEN, TB, MAX, POL, EXT)

    @@
    expression NLH, HDRLEN, TB, MAX, POL, EXT;
    @@
    -nlmsg_parse_strict(NLH, HDRLEN, TB, MAX, POL, EXT)
    +nlmsg_parse_deprecated_strict(NLH, HDRLEN, TB, MAX, POL, EXT)

    @@
    expression TB, MAX, NLA, POL, EXT;
    @@
    -nla_parse_nested(TB, MAX, NLA, POL, EXT)
    +nla_parse_nested_deprecated(TB, MAX, NLA, POL, EXT)

    @@
    expression START, MAX, POL, EXT;
    @@
    -nla_validate_nested(START, MAX, POL, EXT)
    +nla_validate_nested_deprecated(START, MAX, POL, EXT)

    @@
    expression NLH, HDRLEN, MAX, POL, EXT;
    @@
    -nlmsg_validate(NLH, HDRLEN, MAX, POL, EXT)
    +nlmsg_validate_deprecated(NLH, HDRLEN, MAX, POL, EXT)

For this patch, don't actually add the strict, non-renamed versions
yet so that it breaks compile if I get it wrong.

Also, while at it, make nla_validate and nla_parse go down to a
common __nla_validate_parse() function to avoid code duplication.

Ultimately, this allows us to have very strict validation for every
new caller of nla_parse()/nlmsg_parse() etc as re-introduced in the
next patch, while existing things will continue to work as is.

In effect then, this adds fully strict validation for any new command.

Signed-off-by: Johannes Berg &lt;johannes.berg@intel.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>netlink: make nla_nest_start() add NLA_F_NESTED flag</title>
<updated>2019-04-27T21:03:44+00:00</updated>
<author>
<name>Michal Kubecek</name>
<email>mkubecek@suse.cz</email>
</author>
<published>2019-04-26T09:13:06+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=ae0be8de9a53cda3505865c11826d8ff0640237c'/>
<id>ae0be8de9a53cda3505865c11826d8ff0640237c</id>
<content type='text'>
Even if the NLA_F_NESTED flag was introduced more than 11 years ago, most
netlink based interfaces (including recently added ones) are still not
setting it in kernel generated messages. Without the flag, message parsers
not aware of attribute semantics (e.g. wireshark dissector or libmnl's
mnl_nlmsg_fprintf()) cannot recognize nested attributes and won't display
the structure of their contents.

Unfortunately we cannot just add the flag everywhere as there may be
userspace applications which check nlattr::nla_type directly rather than
through a helper masking out the flags. Therefore the patch renames
nla_nest_start() to nla_nest_start_noflag() and introduces nla_nest_start()
as a wrapper adding NLA_F_NESTED. The calls which add NLA_F_NESTED manually
are rewritten to use nla_nest_start().

Except for changes in include/net/netlink.h, the patch was generated using
this semantic patch:

@@ expression E1, E2; @@
-nla_nest_start(E1, E2)
+nla_nest_start_noflag(E1, E2)

@@ expression E1, E2; @@
-nla_nest_start_noflag(E1, E2 | NLA_F_NESTED)
+nla_nest_start(E1, E2)

Signed-off-by: Michal Kubecek &lt;mkubecek@suse.cz&gt;
Acked-by: Jiri Pirko &lt;jiri@mellanox.com&gt;
Acked-by: David Ahern &lt;dsahern@gmail.com&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>
Even if the NLA_F_NESTED flag was introduced more than 11 years ago, most
netlink based interfaces (including recently added ones) are still not
setting it in kernel generated messages. Without the flag, message parsers
not aware of attribute semantics (e.g. wireshark dissector or libmnl's
mnl_nlmsg_fprintf()) cannot recognize nested attributes and won't display
the structure of their contents.

Unfortunately we cannot just add the flag everywhere as there may be
userspace applications which check nlattr::nla_type directly rather than
through a helper masking out the flags. Therefore the patch renames
nla_nest_start() to nla_nest_start_noflag() and introduces nla_nest_start()
as a wrapper adding NLA_F_NESTED. The calls which add NLA_F_NESTED manually
are rewritten to use nla_nest_start().

Except for changes in include/net/netlink.h, the patch was generated using
this semantic patch:

@@ expression E1, E2; @@
-nla_nest_start(E1, E2)
+nla_nest_start_noflag(E1, E2)

@@ expression E1, E2; @@
-nla_nest_start_noflag(E1, E2 | NLA_F_NESTED)
+nla_nest_start(E1, E2)

Signed-off-by: Michal Kubecek &lt;mkubecek@suse.cz&gt;
Acked-by: Jiri Pirko &lt;jiri@mellanox.com&gt;
Acked-by: David Ahern &lt;dsahern@gmail.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
</feed>
