<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/drivers/net/bonding, branch v4.4.196</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>bonding: Force slave speed check after link state recovery for 802.3ad</title>
<updated>2019-09-06T08:18:05+00:00</updated>
<author>
<name>Thomas Falcon</name>
<email>tlfalcon@linux.ibm.com</email>
</author>
<published>2019-07-16T22:25:10+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=5927e91f5024c2316a29227162b540018aab006e'/>
<id>5927e91f5024c2316a29227162b540018aab006e</id>
<content type='text'>
[ Upstream commit 12185dfe44360f814ac4ead9d22ad2af7511b2e9 ]

The following scenario was encountered during testing of logical
partition mobility on pseries partitions with bonded ibmvnic
adapters in LACP mode.

1. Driver receives a signal that the device has been
   swapped, and it needs to reset to initialize the new
   device.

2. Driver reports loss of carrier and begins initialization.

3. Bonding driver receives NETDEV_CHANGE notifier and checks
   the slave's current speed and duplex settings. Because these
   are unknown at the time, the bond sets its link state to
   BOND_LINK_FAIL and handles the speed update, clearing
   AD_PORT_LACP_ENABLE.

4. Driver finishes recovery and reports that the carrier is on.

5. Bond receives a new notification and checks the speed again.
   The speeds are valid but miimon has not altered the link
   state yet.  AD_PORT_LACP_ENABLE remains off.

Because the slave's link state is still BOND_LINK_FAIL,
no further port checks are made when it recovers. Though
the slave devices are operational and have valid speed
and duplex settings, the bond will not send LACPDU's. The
simplest fix I can see is to force another speed check
in bond_miimon_commit. This way the bond will update
AD_PORT_LACP_ENABLE if needed when transitioning from
BOND_LINK_FAIL to BOND_LINK_UP.

CC: Jarod Wilson &lt;jarod@redhat.com&gt;
CC: Jay Vosburgh &lt;j.vosburgh@gmail.com&gt;
CC: Veaceslav Falico &lt;vfalico@gmail.com&gt;
CC: Andy Gospodarek &lt;andy@greyhouse.net&gt;
Signed-off-by: Thomas Falcon &lt;tlfalcon@linux.ibm.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 12185dfe44360f814ac4ead9d22ad2af7511b2e9 ]

The following scenario was encountered during testing of logical
partition mobility on pseries partitions with bonded ibmvnic
adapters in LACP mode.

1. Driver receives a signal that the device has been
   swapped, and it needs to reset to initialize the new
   device.

2. Driver reports loss of carrier and begins initialization.

3. Bonding driver receives NETDEV_CHANGE notifier and checks
   the slave's current speed and duplex settings. Because these
   are unknown at the time, the bond sets its link state to
   BOND_LINK_FAIL and handles the speed update, clearing
   AD_PORT_LACP_ENABLE.

4. Driver finishes recovery and reports that the carrier is on.

5. Bond receives a new notification and checks the speed again.
   The speeds are valid but miimon has not altered the link
   state yet.  AD_PORT_LACP_ENABLE remains off.

Because the slave's link state is still BOND_LINK_FAIL,
no further port checks are made when it recovers. Though
the slave devices are operational and have valid speed
and duplex settings, the bond will not send LACPDU's. The
simplest fix I can see is to force another speed check
in bond_miimon_commit. This way the bond will update
AD_PORT_LACP_ENABLE if needed when transitioning from
BOND_LINK_FAIL to BOND_LINK_UP.

CC: Jarod Wilson &lt;jarod@redhat.com&gt;
CC: Jay Vosburgh &lt;j.vosburgh@gmail.com&gt;
CC: Veaceslav Falico &lt;vfalico@gmail.com&gt;
CC: Andy Gospodarek &lt;andy@greyhouse.net&gt;
Signed-off-by: Thomas Falcon &lt;tlfalcon@linux.ibm.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>bonding: Add vlan tx offload to hw_enc_features</title>
<updated>2019-08-25T08:53:06+00:00</updated>
<author>
<name>YueHaibing</name>
<email>yuehaibing@huawei.com</email>
</author>
<published>2019-08-07T02:19:59+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=a0f592c507daa933ca77af34b5d0492102918a9b'/>
<id>a0f592c507daa933ca77af34b5d0492102918a9b</id>
<content type='text'>
[ Upstream commit d595b03de2cb0bdf9bcdf35ff27840cc3a37158f ]

As commit 30d8177e8ac7 ("bonding: Always enable vlan tx offload")
said, we should always enable bonding's vlan tx offload, pass the
vlan packets to the slave devices with vlan tci, let them to handle
vlan implementation.

Now if encapsulation protocols like VXLAN is used, skb-&gt;encapsulation
may be set, then the packet is passed to vlan device which based on
bonding device. However in netif_skb_features(), the check of
hw_enc_features:

	 if (skb-&gt;encapsulation)
                 features &amp;= dev-&gt;hw_enc_features;

clears NETIF_F_HW_VLAN_CTAG_TX/NETIF_F_HW_VLAN_STAG_TX. This results
in same issue in commit 30d8177e8ac7 like this:

vlan_dev_hard_start_xmit
  --&gt;dev_queue_xmit
    --&gt;validate_xmit_skb
      --&gt;netif_skb_features //NETIF_F_HW_VLAN_CTAG_TX is cleared
      --&gt;validate_xmit_vlan
        --&gt;__vlan_hwaccel_push_inside //skb-&gt;tci is cleared
...
 --&gt; bond_start_xmit
   --&gt; bond_xmit_hash //BOND_XMIT_POLICY_ENCAP34
     --&gt; __skb_flow_dissect // nhoff point to IP header
        --&gt;  case htons(ETH_P_8021Q)
             // skb_vlan_tag_present is false, so
             vlan = __skb_header_pointer(skb, nhoff, sizeof(_vlan),
             //vlan point to ip header wrongly

Fixes: b2a103e6d0af ("bonding: convert to ndo_fix_features")
Signed-off-by: YueHaibing &lt;yuehaibing@huawei.com&gt;
Acked-by: Jay Vosburgh &lt;jay.vosburgh@canonical.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 d595b03de2cb0bdf9bcdf35ff27840cc3a37158f ]

As commit 30d8177e8ac7 ("bonding: Always enable vlan tx offload")
said, we should always enable bonding's vlan tx offload, pass the
vlan packets to the slave devices with vlan tci, let them to handle
vlan implementation.

Now if encapsulation protocols like VXLAN is used, skb-&gt;encapsulation
may be set, then the packet is passed to vlan device which based on
bonding device. However in netif_skb_features(), the check of
hw_enc_features:

	 if (skb-&gt;encapsulation)
                 features &amp;= dev-&gt;hw_enc_features;

clears NETIF_F_HW_VLAN_CTAG_TX/NETIF_F_HW_VLAN_STAG_TX. This results
in same issue in commit 30d8177e8ac7 like this:

vlan_dev_hard_start_xmit
  --&gt;dev_queue_xmit
    --&gt;validate_xmit_skb
      --&gt;netif_skb_features //NETIF_F_HW_VLAN_CTAG_TX is cleared
      --&gt;validate_xmit_vlan
        --&gt;__vlan_hwaccel_push_inside //skb-&gt;tci is cleared
...
 --&gt; bond_start_xmit
   --&gt; bond_xmit_hash //BOND_XMIT_POLICY_ENCAP34
     --&gt; __skb_flow_dissect // nhoff point to IP header
        --&gt;  case htons(ETH_P_8021Q)
             // skb_vlan_tag_present is false, so
             vlan = __skb_header_pointer(skb, nhoff, sizeof(_vlan),
             //vlan point to ip header wrongly

Fixes: b2a103e6d0af ("bonding: convert to ndo_fix_features")
Signed-off-by: YueHaibing &lt;yuehaibing@huawei.com&gt;
Acked-by: Jay Vosburgh &lt;jay.vosburgh@canonical.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>bonding: validate ip header before check IPPROTO_IGMP</title>
<updated>2019-08-04T07:34:55+00:00</updated>
<author>
<name>Cong Wang</name>
<email>xiyou.wangcong@gmail.com</email>
</author>
<published>2019-07-02T03:40:24+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=2eb5ddc2bf38e2a2b9ec461ab18d91b43d9f8d93'/>
<id>2eb5ddc2bf38e2a2b9ec461ab18d91b43d9f8d93</id>
<content type='text'>
[ Upstream commit 9d1bc24b52fb8c5d859f9a47084bf1179470e04c ]

bond_xmit_roundrobin() checks for IGMP packets but it parses
the IP header even before checking skb-&gt;protocol.

We should validate the IP header with pskb_may_pull() before
using iph-&gt;protocol.

Reported-and-tested-by: syzbot+e5be16aa39ad6e755391@syzkaller.appspotmail.com
Fixes: a2fd940f4cff ("bonding: fix broken multicast with round-robin mode")
Cc: Jay Vosburgh &lt;j.vosburgh@gmail.com&gt;
Cc: Veaceslav Falico &lt;vfalico@gmail.com&gt;
Cc: Andy Gospodarek &lt;andy@greyhouse.net&gt;
Signed-off-by: Cong Wang &lt;xiyou.wangcong@gmail.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 9d1bc24b52fb8c5d859f9a47084bf1179470e04c ]

bond_xmit_roundrobin() checks for IGMP packets but it parses
the IP header even before checking skb-&gt;protocol.

We should validate the IP header with pskb_may_pull() before
using iph-&gt;protocol.

Reported-and-tested-by: syzbot+e5be16aa39ad6e755391@syzkaller.appspotmail.com
Fixes: a2fd940f4cff ("bonding: fix broken multicast with round-robin mode")
Cc: Jay Vosburgh &lt;j.vosburgh@gmail.com&gt;
Cc: Veaceslav Falico &lt;vfalico@gmail.com&gt;
Cc: Andy Gospodarek &lt;andy@greyhouse.net&gt;
Signed-off-by: Cong Wang &lt;xiyou.wangcong@gmail.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>bonding: Always enable vlan tx offload</title>
<updated>2019-07-10T07:56:38+00:00</updated>
<author>
<name>YueHaibing</name>
<email>yuehaibing@huawei.com</email>
</author>
<published>2019-06-26T08:08:44+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=ec109e6a9a1b1c5b1523d922c77f5195dee3dc39'/>
<id>ec109e6a9a1b1c5b1523d922c77f5195dee3dc39</id>
<content type='text'>
[ Upstream commit 30d8177e8ac776d89d387fad547af6a0f599210e ]

We build vlan on top of bonding interface, which vlan offload
is off, bond mode is 802.3ad (LACP) and xmit_hash_policy is
BOND_XMIT_POLICY_ENCAP34.

Because vlan tx offload is off, vlan tci is cleared and skb push
the vlan header in validate_xmit_vlan() while sending from vlan
devices. Then in bond_xmit_hash, __skb_flow_dissect() fails to
get information from protocol headers encapsulated within vlan,
because 'nhoff' is points to IP header, so bond hashing is based
on layer 2 info, which fails to distribute packets across slaves.

This patch always enable bonding's vlan tx offload, pass the vlan
packets to the slave devices with vlan tci, let them to handle
vlan implementation.

Fixes: 278339a42a1b ("bonding: propogate vlan_features to bonding master")
Suggested-by: Jiri Pirko &lt;jiri@resnulli.us&gt;
Signed-off-by: YueHaibing &lt;yuehaibing@huawei.com&gt;
Acked-by: Jiri Pirko &lt;jiri@mellanox.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 30d8177e8ac776d89d387fad547af6a0f599210e ]

We build vlan on top of bonding interface, which vlan offload
is off, bond mode is 802.3ad (LACP) and xmit_hash_policy is
BOND_XMIT_POLICY_ENCAP34.

Because vlan tx offload is off, vlan tci is cleared and skb push
the vlan header in validate_xmit_vlan() while sending from vlan
devices. Then in bond_xmit_hash, __skb_flow_dissect() fails to
get information from protocol headers encapsulated within vlan,
because 'nhoff' is points to IP header, so bond hashing is based
on layer 2 info, which fails to distribute packets across slaves.

This patch always enable bonding's vlan tx offload, pass the vlan
packets to the slave devices with vlan tci, let them to handle
vlan implementation.

Fixes: 278339a42a1b ("bonding: propogate vlan_features to bonding master")
Suggested-by: Jiri Pirko &lt;jiri@resnulli.us&gt;
Signed-off-by: YueHaibing &lt;yuehaibing@huawei.com&gt;
Acked-by: Jiri Pirko &lt;jiri@mellanox.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>bonding: fix arp_validate toggling in active-backup mode</title>
<updated>2019-05-16T17:45:18+00:00</updated>
<author>
<name>Jarod Wilson</name>
<email>jarod@redhat.com</email>
</author>
<published>2019-05-10T21:57:09+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=7a22a4ea67b7f9453bad7fcf2b7504d23d2aa602'/>
<id>7a22a4ea67b7f9453bad7fcf2b7504d23d2aa602</id>
<content type='text'>
[ Upstream commit a9b8a2b39ce65df45687cf9ef648885c2a99fe75 ]

There's currently a problem with toggling arp_validate on and off with an
active-backup bond. At the moment, you can start up a bond, like so:

modprobe bonding mode=1 arp_interval=100 arp_validate=0 arp_ip_targets=192.168.1.1
ip link set bond0 down
echo "ens4f0" &gt; /sys/class/net/bond0/bonding/slaves
echo "ens4f1" &gt; /sys/class/net/bond0/bonding/slaves
ip link set bond0 up
ip addr add 192.168.1.2/24 dev bond0

Pings to 192.168.1.1 work just fine. Now turn on arp_validate:

echo 1 &gt; /sys/class/net/bond0/bonding/arp_validate

Pings to 192.168.1.1 continue to work just fine. Now when you go to turn
arp_validate off again, the link falls flat on it's face:

echo 0 &gt; /sys/class/net/bond0/bonding/arp_validate
dmesg
...
[133191.911987] bond0: Setting arp_validate to none (0)
[133194.257793] bond0: bond_should_notify_peers: slave ens4f0
[133194.258031] bond0: link status definitely down for interface ens4f0, disabling it
[133194.259000] bond0: making interface ens4f1 the new active one
[133197.330130] bond0: link status definitely down for interface ens4f1, disabling it
[133197.331191] bond0: now running without any active interface!

The problem lies in bond_options.c, where passing in arp_validate=0
results in bond-&gt;recv_probe getting set to NULL. This flies directly in
the face of commit 3fe68df97c7f, which says we need to set recv_probe =
bond_arp_recv, even if we're not using arp_validate. Said commit fixed
this in bond_option_arp_interval_set, but missed that we can get to that
same state in bond_option_arp_validate_set as well.

One solution would be to universally set recv_probe = bond_arp_recv here
as well, but I don't think bond_option_arp_validate_set has any business
touching recv_probe at all, and that should be left to the arp_interval
code, so we can just make things much tidier here.

Fixes: 3fe68df97c7f ("bonding: always set recv_probe to bond_arp_rcv in arp monitor")
CC: Jay Vosburgh &lt;j.vosburgh@gmail.com&gt;
CC: Veaceslav Falico &lt;vfalico@gmail.com&gt;
CC: Andy Gospodarek &lt;andy@greyhouse.net&gt;
CC: "David S. Miller" &lt;davem@davemloft.net&gt;
CC: netdev@vger.kernel.org
Signed-off-by: Jarod Wilson &lt;jarod@redhat.com&gt;
Signed-off-by: Jay Vosburgh &lt;jay.vosburgh@canonical.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 a9b8a2b39ce65df45687cf9ef648885c2a99fe75 ]

There's currently a problem with toggling arp_validate on and off with an
active-backup bond. At the moment, you can start up a bond, like so:

modprobe bonding mode=1 arp_interval=100 arp_validate=0 arp_ip_targets=192.168.1.1
ip link set bond0 down
echo "ens4f0" &gt; /sys/class/net/bond0/bonding/slaves
echo "ens4f1" &gt; /sys/class/net/bond0/bonding/slaves
ip link set bond0 up
ip addr add 192.168.1.2/24 dev bond0

Pings to 192.168.1.1 work just fine. Now turn on arp_validate:

echo 1 &gt; /sys/class/net/bond0/bonding/arp_validate

Pings to 192.168.1.1 continue to work just fine. Now when you go to turn
arp_validate off again, the link falls flat on it's face:

echo 0 &gt; /sys/class/net/bond0/bonding/arp_validate
dmesg
...
[133191.911987] bond0: Setting arp_validate to none (0)
[133194.257793] bond0: bond_should_notify_peers: slave ens4f0
[133194.258031] bond0: link status definitely down for interface ens4f0, disabling it
[133194.259000] bond0: making interface ens4f1 the new active one
[133197.330130] bond0: link status definitely down for interface ens4f1, disabling it
[133197.331191] bond0: now running without any active interface!

The problem lies in bond_options.c, where passing in arp_validate=0
results in bond-&gt;recv_probe getting set to NULL. This flies directly in
the face of commit 3fe68df97c7f, which says we need to set recv_probe =
bond_arp_recv, even if we're not using arp_validate. Said commit fixed
this in bond_option_arp_interval_set, but missed that we can get to that
same state in bond_option_arp_validate_set as well.

One solution would be to universally set recv_probe = bond_arp_recv here
as well, but I don't think bond_option_arp_validate_set has any business
touching recv_probe at all, and that should be left to the arp_interval
code, so we can just make things much tidier here.

Fixes: 3fe68df97c7f ("bonding: always set recv_probe to bond_arp_rcv in arp monitor")
CC: Jay Vosburgh &lt;j.vosburgh@gmail.com&gt;
CC: Veaceslav Falico &lt;vfalico@gmail.com&gt;
CC: Andy Gospodarek &lt;andy@greyhouse.net&gt;
CC: "David S. Miller" &lt;davem@davemloft.net&gt;
CC: netdev@vger.kernel.org
Signed-off-by: Jarod Wilson &lt;jarod@redhat.com&gt;
Signed-off-by: Jay Vosburgh &lt;jay.vosburgh@canonical.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>bonding: show full hw address in sysfs for slave entries</title>
<updated>2019-05-16T17:45:01+00:00</updated>
<author>
<name>Konstantin Khorenko</name>
<email>khorenko@virtuozzo.com</email>
</author>
<published>2019-03-28T10:29:21+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=cd43ccbfb5fbbab548b10dc68bb3bd09992511b2'/>
<id>cd43ccbfb5fbbab548b10dc68bb3bd09992511b2</id>
<content type='text'>
[ Upstream commit 18bebc6dd3281955240062655a4df35eef2c46b3 ]

Bond expects ethernet hwaddr for its slave, but it can be longer than 6
bytes - infiniband interface for example.

 # cat /sys/devices/&lt;skipped&gt;/net/ib0/address
 80:00:02:08:fe:80:00:00:00:00:00:00:7c:fe:90:03:00:be:5d:e1

 # cat /sys/devices/&lt;skipped&gt;/net/ib0/bonding_slave/perm_hwaddr
 80:00:02:08:fe:80

So print full hwaddr in sysfs "bonding_slave/perm_hwaddr" as well.

Signed-off-by: Konstantin Khorenko &lt;khorenko@virtuozzo.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 18bebc6dd3281955240062655a4df35eef2c46b3 ]

Bond expects ethernet hwaddr for its slave, but it can be longer than 6
bytes - infiniband interface for example.

 # cat /sys/devices/&lt;skipped&gt;/net/ib0/address
 80:00:02:08:fe:80:00:00:00:00:00:00:7c:fe:90:03:00:be:5d:e1

 # cat /sys/devices/&lt;skipped&gt;/net/ib0/bonding_slave/perm_hwaddr
 80:00:02:08:fe:80

So print full hwaddr in sysfs "bonding_slave/perm_hwaddr" as well.

Signed-off-by: Konstantin Khorenko &lt;khorenko@virtuozzo.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>bonding: fix event handling for stacked bonds</title>
<updated>2019-04-27T07:33:59+00:00</updated>
<author>
<name>Sabrina Dubroca</name>
<email>sd@queasysnail.net</email>
</author>
<published>2019-04-12T13:04:10+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=d8e18cccd25e05271ef5741a55b2d3be6220be99'/>
<id>d8e18cccd25e05271ef5741a55b2d3be6220be99</id>
<content type='text'>
[ Upstream commit 92480b3977fd3884649d404cbbaf839b70035699 ]

When a bond is enslaved to another bond, bond_netdev_event() only
handles the event as if the bond is a master, and skips treating the
bond as a slave.

This leads to a refcount leak on the slave, since we don't remove the
adjacency to its master and the master holds a reference on the slave.

Reproducer:
  ip link add bondL type bond
  ip link add bondU type bond
  ip link set bondL master bondU
  ip link del bondL

No "Fixes:" tag, this code is older than git history.

Signed-off-by: Sabrina Dubroca &lt;sd@queasysnail.net&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 92480b3977fd3884649d404cbbaf839b70035699 ]

When a bond is enslaved to another bond, bond_netdev_event() only
handles the event as if the bond is a master, and skips treating the
bond as a slave.

This leads to a refcount leak on the slave, since we don't remove the
adjacency to its master and the master holds a reference on the slave.

Reproducer:
  ip link add bondL type bond
  ip link add bondU type bond
  ip link set bondL master bondU
  ip link del bondL

No "Fixes:" tag, this code is older than git history.

Signed-off-by: Sabrina Dubroca &lt;sd@queasysnail.net&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>bonding: fix 802.3ad state sent to partner when unbinding slave</title>
<updated>2018-12-21T13:09:52+00:00</updated>
<author>
<name>Toni Peltonen</name>
<email>peltzi@peltzi.fi</email>
</author>
<published>2018-11-27T14:56:57+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=25b077464a6b0c3f5e2196adc41d7d2d932c69b2'/>
<id>25b077464a6b0c3f5e2196adc41d7d2d932c69b2</id>
<content type='text'>
[ Upstream commit 3b5b3a3331d141e8f2a7aaae3a94dfa1e61ecbe4 ]

Previously when unbinding a slave the 802.3ad implementation only told
partner that the port is not suitable for aggregation by setting the port
aggregation state from aggregatable to individual. This is not enough. If the
physical layer still stays up and we only unbinded this port from the bond there
is nothing in the aggregation status alone to prevent the partner from sending
traffic towards us. To ensure that the partner doesn't consider this
port at all anymore we should also disable collecting and distributing to
signal that this actor is going away. Also clear AD_STATE_SYNCHRONIZATION to
ensure partner exits collecting + distributing state.

I have tested this behaviour againts Arista EOS switches with mlx5 cards
(physical link stays up even when interface is down) and simulated
the same situation virtually Linux &lt;-&gt; Linux with two network namespaces
running two veth device pairs. In both cases setting aggregation to
individual doesn't alone prevent traffic from being to sent towards this
port given that the link stays up in partners end. Partner still keeps
it's end in collecting + distributing state and continues until timeout is
reached. In most cases this means we are losing the traffic partner sends
towards our port while we wait for timeout. This is most visible with slow
periodic time (LACP rate slow).

Other open source implementations like Open VSwitch and libreswitch, and
vendor implementations like Arista EOS, seem to disable collecting +
distributing to when doing similar port disabling/detaching/removing change.
With this patch kernel implementation would behave the same way and ensure
partner doesn't consider our actor viable anymore.

Signed-off-by: Toni Peltonen &lt;peltzi@peltzi.fi&gt;
Signed-off-by: Jay Vosburgh &lt;jay.vosburgh@canonical.com&gt;
Acked-by: Jonathan Toppins &lt;jtoppins@redhat.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 3b5b3a3331d141e8f2a7aaae3a94dfa1e61ecbe4 ]

Previously when unbinding a slave the 802.3ad implementation only told
partner that the port is not suitable for aggregation by setting the port
aggregation state from aggregatable to individual. This is not enough. If the
physical layer still stays up and we only unbinded this port from the bond there
is nothing in the aggregation status alone to prevent the partner from sending
traffic towards us. To ensure that the partner doesn't consider this
port at all anymore we should also disable collecting and distributing to
signal that this actor is going away. Also clear AD_STATE_SYNCHRONIZATION to
ensure partner exits collecting + distributing state.

I have tested this behaviour againts Arista EOS switches with mlx5 cards
(physical link stays up even when interface is down) and simulated
the same situation virtually Linux &lt;-&gt; Linux with two network namespaces
running two veth device pairs. In both cases setting aggregation to
individual doesn't alone prevent traffic from being to sent towards this
port given that the link stays up in partners end. Partner still keeps
it's end in collecting + distributing state and continues until timeout is
reached. In most cases this means we are losing the traffic partner sends
towards our port while we wait for timeout. This is most visible with slow
periodic time (LACP rate slow).

Other open source implementations like Open VSwitch and libreswitch, and
vendor implementations like Arista EOS, seem to disable collecting +
distributing to when doing similar port disabling/detaching/removing change.
With this patch kernel implementation would behave the same way and ensure
partner doesn't consider our actor viable anymore.

Signed-off-by: Toni Peltonen &lt;peltzi@peltzi.fi&gt;
Signed-off-by: Jay Vosburgh &lt;jay.vosburgh@canonical.com&gt;
Acked-by: Jonathan Toppins &lt;jtoppins@redhat.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>bonding: avoid defaulting hard_header_len to ETH_HLEN on slave removal</title>
<updated>2018-11-10T15:41:40+00:00</updated>
<author>
<name>Paolo Abeni</name>
<email>pabeni@redhat.com</email>
</author>
<published>2017-04-27T17:29:34+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=b1f4be0ee470f7244d85152dbde7f50a23d15c0b'/>
<id>b1f4be0ee470f7244d85152dbde7f50a23d15c0b</id>
<content type='text'>
[ Upstream commit 19cdead3e2ef8ed765c5d1ce48057ca9d97b5094 ]

On slave list updates, the bonding driver computes its hard_header_len
as the maximum of all enslaved devices's hard_header_len.
If the slave list is empty, e.g. on last enslaved device removal,
ETH_HLEN is used.

Since the bonding header_ops are set only when the first enslaved
device is attached, the above can lead to header_ops-&gt;create()
being called with the wrong skb headroom in place.

If bond0 is configured on top of ipoib devices, with the
following commands:

ifup bond0
for slave in $BOND_SLAVES_LIST; do
	ip link set dev $slave nomaster
done
ping -c 1 &lt;ip on bond0 subnet&gt;

we will obtain a skb_under_panic() with a similar call trace:
	skb_push+0x3d/0x40
	push_pseudo_header+0x17/0x30 [ib_ipoib]
	ipoib_hard_header+0x4e/0x80 [ib_ipoib]
	arp_create+0x12f/0x220
	arp_send_dst.part.19+0x28/0x50
	arp_solicit+0x115/0x290
	neigh_probe+0x4d/0x70
	__neigh_event_send+0xa7/0x230
	neigh_resolve_output+0x12e/0x1c0
	ip_finish_output2+0x14b/0x390
	ip_finish_output+0x136/0x1e0
	ip_output+0x76/0xe0
	ip_local_out+0x35/0x40
	ip_send_skb+0x19/0x40
	ip_push_pending_frames+0x33/0x40
	raw_sendmsg+0x7d3/0xb50
	inet_sendmsg+0x31/0xb0
	sock_sendmsg+0x38/0x50
	SYSC_sendto+0x102/0x190
	SyS_sendto+0xe/0x10
	do_syscall_64+0x67/0x180
	entry_SYSCALL64_slow_path+0x25/0x25

This change addresses the issue avoiding updating the bonding device
hard_header_len when the slaves list become empty, forbidding to
shrink it below the value used by header_ops-&gt;create().

The bug is there since commit 54ef31371407 ("[PATCH] bonding: Handle large
hard_header_len") but the panic can be triggered only since
commit fc791b633515 ("IB/ipoib: move back IB LL address into the hard
header").

Reported-by: Norbert P &lt;noe@physik.uzh.ch&gt;
Fixes: 54ef31371407 ("[PATCH] bonding: Handle large hard_header_len")
Fixes: fc791b633515 ("IB/ipoib: move back IB LL address into the hard header")
Signed-off-by: Marcelo Ricardo Leitner &lt;marcelo.leitner@gmail.com&gt;
Signed-off-by: Paolo Abeni &lt;pabeni@redhat.com&gt;
Signed-off-by: Jay Vosburgh &lt;jay.vosburgh@canonical.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 19cdead3e2ef8ed765c5d1ce48057ca9d97b5094 ]

On slave list updates, the bonding driver computes its hard_header_len
as the maximum of all enslaved devices's hard_header_len.
If the slave list is empty, e.g. on last enslaved device removal,
ETH_HLEN is used.

Since the bonding header_ops are set only when the first enslaved
device is attached, the above can lead to header_ops-&gt;create()
being called with the wrong skb headroom in place.

If bond0 is configured on top of ipoib devices, with the
following commands:

ifup bond0
for slave in $BOND_SLAVES_LIST; do
	ip link set dev $slave nomaster
done
ping -c 1 &lt;ip on bond0 subnet&gt;

we will obtain a skb_under_panic() with a similar call trace:
	skb_push+0x3d/0x40
	push_pseudo_header+0x17/0x30 [ib_ipoib]
	ipoib_hard_header+0x4e/0x80 [ib_ipoib]
	arp_create+0x12f/0x220
	arp_send_dst.part.19+0x28/0x50
	arp_solicit+0x115/0x290
	neigh_probe+0x4d/0x70
	__neigh_event_send+0xa7/0x230
	neigh_resolve_output+0x12e/0x1c0
	ip_finish_output2+0x14b/0x390
	ip_finish_output+0x136/0x1e0
	ip_output+0x76/0xe0
	ip_local_out+0x35/0x40
	ip_send_skb+0x19/0x40
	ip_push_pending_frames+0x33/0x40
	raw_sendmsg+0x7d3/0xb50
	inet_sendmsg+0x31/0xb0
	sock_sendmsg+0x38/0x50
	SYSC_sendto+0x102/0x190
	SyS_sendto+0xe/0x10
	do_syscall_64+0x67/0x180
	entry_SYSCALL64_slow_path+0x25/0x25

This change addresses the issue avoiding updating the bonding device
hard_header_len when the slaves list become empty, forbidding to
shrink it below the value used by header_ops-&gt;create().

The bug is there since commit 54ef31371407 ("[PATCH] bonding: Handle large
hard_header_len") but the panic can be triggered only since
commit fc791b633515 ("IB/ipoib: move back IB LL address into the hard
header").

Reported-by: Norbert P &lt;noe@physik.uzh.ch&gt;
Fixes: 54ef31371407 ("[PATCH] bonding: Handle large hard_header_len")
Fixes: fc791b633515 ("IB/ipoib: move back IB LL address into the hard header")
Signed-off-by: Marcelo Ricardo Leitner &lt;marcelo.leitner@gmail.com&gt;
Signed-off-by: Paolo Abeni &lt;pabeni@redhat.com&gt;
Signed-off-by: Jay Vosburgh &lt;jay.vosburgh@canonical.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>bonding: avoid possible dead-lock</title>
<updated>2018-10-20T07:52:36+00:00</updated>
<author>
<name>Mahesh Bandewar</name>
<email>maheshb@google.com</email>
</author>
<published>2018-09-24T21:40:11+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=2691921c7d26efc18400162b77c794d6a921afe5'/>
<id>2691921c7d26efc18400162b77c794d6a921afe5</id>
<content type='text'>
[ Upstream commit d4859d749aa7090ffb743d15648adb962a1baeae ]

Syzkaller reported this on a slightly older kernel but it's still
applicable to the current kernel -

======================================================
WARNING: possible circular locking dependency detected
4.18.0-next-20180823+ #46 Not tainted
------------------------------------------------------
syz-executor4/26841 is trying to acquire lock:
00000000dd41ef48 ((wq_completion)bond_dev-&gt;name){+.+.}, at: flush_workqueue+0x2db/0x1e10 kernel/workqueue.c:2652

but task is already holding lock:
00000000768ab431 (rtnl_mutex){+.+.}, at: rtnl_lock net/core/rtnetlink.c:77 [inline]
00000000768ab431 (rtnl_mutex){+.+.}, at: rtnetlink_rcv_msg+0x412/0xc30 net/core/rtnetlink.c:4708

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-&gt; #2 (rtnl_mutex){+.+.}:
       __mutex_lock_common kernel/locking/mutex.c:925 [inline]
       __mutex_lock+0x171/0x1700 kernel/locking/mutex.c:1073
       mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1088
       rtnl_lock+0x17/0x20 net/core/rtnetlink.c:77
       bond_netdev_notify drivers/net/bonding/bond_main.c:1310 [inline]
       bond_netdev_notify_work+0x44/0xd0 drivers/net/bonding/bond_main.c:1320
       process_one_work+0xc73/0x1aa0 kernel/workqueue.c:2153
       worker_thread+0x189/0x13c0 kernel/workqueue.c:2296
       kthread+0x35a/0x420 kernel/kthread.c:246
       ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:415

-&gt; #1 ((work_completion)(&amp;(&amp;nnw-&gt;work)-&gt;work)){+.+.}:
       process_one_work+0xc0b/0x1aa0 kernel/workqueue.c:2129
       worker_thread+0x189/0x13c0 kernel/workqueue.c:2296
       kthread+0x35a/0x420 kernel/kthread.c:246
       ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:415

-&gt; #0 ((wq_completion)bond_dev-&gt;name){+.+.}:
       lock_acquire+0x1e4/0x4f0 kernel/locking/lockdep.c:3901
       flush_workqueue+0x30a/0x1e10 kernel/workqueue.c:2655
       drain_workqueue+0x2a9/0x640 kernel/workqueue.c:2820
       destroy_workqueue+0xc6/0x9d0 kernel/workqueue.c:4155
       __alloc_workqueue_key+0xef9/0x1190 kernel/workqueue.c:4138
       bond_init+0x269/0x940 drivers/net/bonding/bond_main.c:4734
       register_netdevice+0x337/0x1100 net/core/dev.c:8410
       bond_newlink+0x49/0xa0 drivers/net/bonding/bond_netlink.c:453
       rtnl_newlink+0xef4/0x1d50 net/core/rtnetlink.c:3099
       rtnetlink_rcv_msg+0x46e/0xc30 net/core/rtnetlink.c:4711
       netlink_rcv_skb+0x172/0x440 net/netlink/af_netlink.c:2454
       rtnetlink_rcv+0x1c/0x20 net/core/rtnetlink.c:4729
       netlink_unicast_kernel net/netlink/af_netlink.c:1317 [inline]
       netlink_unicast+0x5a0/0x760 net/netlink/af_netlink.c:1343
       netlink_sendmsg+0xa18/0xfc0 net/netlink/af_netlink.c:1908
       sock_sendmsg_nosec net/socket.c:622 [inline]
       sock_sendmsg+0xd5/0x120 net/socket.c:632
       ___sys_sendmsg+0x7fd/0x930 net/socket.c:2115
       __sys_sendmsg+0x11d/0x290 net/socket.c:2153
       __do_sys_sendmsg net/socket.c:2162 [inline]
       __se_sys_sendmsg net/socket.c:2160 [inline]
       __x64_sys_sendmsg+0x78/0xb0 net/socket.c:2160
       do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
       entry_SYSCALL_64_after_hwframe+0x49/0xbe

other info that might help us debug this:

Chain exists of:
  (wq_completion)bond_dev-&gt;name --&gt; (work_completion)(&amp;(&amp;nnw-&gt;work)-&gt;work) --&gt; rtnl_mutex

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(rtnl_mutex);
                               lock((work_completion)(&amp;(&amp;nnw-&gt;work)-&gt;work));
                               lock(rtnl_mutex);
  lock((wq_completion)bond_dev-&gt;name);

 *** DEADLOCK ***

1 lock held by syz-executor4/26841:

stack backtrace:
CPU: 1 PID: 26841 Comm: syz-executor4 Not tainted 4.18.0-next-20180823+ #46
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1c9/0x2b4 lib/dump_stack.c:113
 print_circular_bug.isra.34.cold.55+0x1bd/0x27d kernel/locking/lockdep.c:1222
 check_prev_add kernel/locking/lockdep.c:1862 [inline]
 check_prevs_add kernel/locking/lockdep.c:1975 [inline]
 validate_chain kernel/locking/lockdep.c:2416 [inline]
 __lock_acquire+0x3449/0x5020 kernel/locking/lockdep.c:3412
 lock_acquire+0x1e4/0x4f0 kernel/locking/lockdep.c:3901
 flush_workqueue+0x30a/0x1e10 kernel/workqueue.c:2655
 drain_workqueue+0x2a9/0x640 kernel/workqueue.c:2820
 destroy_workqueue+0xc6/0x9d0 kernel/workqueue.c:4155
 __alloc_workqueue_key+0xef9/0x1190 kernel/workqueue.c:4138
 bond_init+0x269/0x940 drivers/net/bonding/bond_main.c:4734
 register_netdevice+0x337/0x1100 net/core/dev.c:8410
 bond_newlink+0x49/0xa0 drivers/net/bonding/bond_netlink.c:453
 rtnl_newlink+0xef4/0x1d50 net/core/rtnetlink.c:3099
 rtnetlink_rcv_msg+0x46e/0xc30 net/core/rtnetlink.c:4711
 netlink_rcv_skb+0x172/0x440 net/netlink/af_netlink.c:2454
 rtnetlink_rcv+0x1c/0x20 net/core/rtnetlink.c:4729
 netlink_unicast_kernel net/netlink/af_netlink.c:1317 [inline]
 netlink_unicast+0x5a0/0x760 net/netlink/af_netlink.c:1343
 netlink_sendmsg+0xa18/0xfc0 net/netlink/af_netlink.c:1908
 sock_sendmsg_nosec net/socket.c:622 [inline]
 sock_sendmsg+0xd5/0x120 net/socket.c:632
 ___sys_sendmsg+0x7fd/0x930 net/socket.c:2115
 __sys_sendmsg+0x11d/0x290 net/socket.c:2153
 __do_sys_sendmsg net/socket.c:2162 [inline]
 __se_sys_sendmsg net/socket.c:2160 [inline]
 __x64_sys_sendmsg+0x78/0xb0 net/socket.c:2160
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x457089
Code: fd b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 &lt;48&gt; 3d 01 f0 ff ff 0f 83 cb b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f2df20a5c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f2df20a66d4 RCX: 0000000000457089
RDX: 0000000000000000 RSI: 0000000020000180 RDI: 0000000000000003
RBP: 0000000000930140 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000004d40b8 R14: 00000000004c8ad8 R15: 0000000000000001

Signed-off-by: Mahesh Bandewar &lt;maheshb@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 d4859d749aa7090ffb743d15648adb962a1baeae ]

Syzkaller reported this on a slightly older kernel but it's still
applicable to the current kernel -

======================================================
WARNING: possible circular locking dependency detected
4.18.0-next-20180823+ #46 Not tainted
------------------------------------------------------
syz-executor4/26841 is trying to acquire lock:
00000000dd41ef48 ((wq_completion)bond_dev-&gt;name){+.+.}, at: flush_workqueue+0x2db/0x1e10 kernel/workqueue.c:2652

but task is already holding lock:
00000000768ab431 (rtnl_mutex){+.+.}, at: rtnl_lock net/core/rtnetlink.c:77 [inline]
00000000768ab431 (rtnl_mutex){+.+.}, at: rtnetlink_rcv_msg+0x412/0xc30 net/core/rtnetlink.c:4708

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-&gt; #2 (rtnl_mutex){+.+.}:
       __mutex_lock_common kernel/locking/mutex.c:925 [inline]
       __mutex_lock+0x171/0x1700 kernel/locking/mutex.c:1073
       mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1088
       rtnl_lock+0x17/0x20 net/core/rtnetlink.c:77
       bond_netdev_notify drivers/net/bonding/bond_main.c:1310 [inline]
       bond_netdev_notify_work+0x44/0xd0 drivers/net/bonding/bond_main.c:1320
       process_one_work+0xc73/0x1aa0 kernel/workqueue.c:2153
       worker_thread+0x189/0x13c0 kernel/workqueue.c:2296
       kthread+0x35a/0x420 kernel/kthread.c:246
       ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:415

-&gt; #1 ((work_completion)(&amp;(&amp;nnw-&gt;work)-&gt;work)){+.+.}:
       process_one_work+0xc0b/0x1aa0 kernel/workqueue.c:2129
       worker_thread+0x189/0x13c0 kernel/workqueue.c:2296
       kthread+0x35a/0x420 kernel/kthread.c:246
       ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:415

-&gt; #0 ((wq_completion)bond_dev-&gt;name){+.+.}:
       lock_acquire+0x1e4/0x4f0 kernel/locking/lockdep.c:3901
       flush_workqueue+0x30a/0x1e10 kernel/workqueue.c:2655
       drain_workqueue+0x2a9/0x640 kernel/workqueue.c:2820
       destroy_workqueue+0xc6/0x9d0 kernel/workqueue.c:4155
       __alloc_workqueue_key+0xef9/0x1190 kernel/workqueue.c:4138
       bond_init+0x269/0x940 drivers/net/bonding/bond_main.c:4734
       register_netdevice+0x337/0x1100 net/core/dev.c:8410
       bond_newlink+0x49/0xa0 drivers/net/bonding/bond_netlink.c:453
       rtnl_newlink+0xef4/0x1d50 net/core/rtnetlink.c:3099
       rtnetlink_rcv_msg+0x46e/0xc30 net/core/rtnetlink.c:4711
       netlink_rcv_skb+0x172/0x440 net/netlink/af_netlink.c:2454
       rtnetlink_rcv+0x1c/0x20 net/core/rtnetlink.c:4729
       netlink_unicast_kernel net/netlink/af_netlink.c:1317 [inline]
       netlink_unicast+0x5a0/0x760 net/netlink/af_netlink.c:1343
       netlink_sendmsg+0xa18/0xfc0 net/netlink/af_netlink.c:1908
       sock_sendmsg_nosec net/socket.c:622 [inline]
       sock_sendmsg+0xd5/0x120 net/socket.c:632
       ___sys_sendmsg+0x7fd/0x930 net/socket.c:2115
       __sys_sendmsg+0x11d/0x290 net/socket.c:2153
       __do_sys_sendmsg net/socket.c:2162 [inline]
       __se_sys_sendmsg net/socket.c:2160 [inline]
       __x64_sys_sendmsg+0x78/0xb0 net/socket.c:2160
       do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
       entry_SYSCALL_64_after_hwframe+0x49/0xbe

other info that might help us debug this:

Chain exists of:
  (wq_completion)bond_dev-&gt;name --&gt; (work_completion)(&amp;(&amp;nnw-&gt;work)-&gt;work) --&gt; rtnl_mutex

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(rtnl_mutex);
                               lock((work_completion)(&amp;(&amp;nnw-&gt;work)-&gt;work));
                               lock(rtnl_mutex);
  lock((wq_completion)bond_dev-&gt;name);

 *** DEADLOCK ***

1 lock held by syz-executor4/26841:

stack backtrace:
CPU: 1 PID: 26841 Comm: syz-executor4 Not tainted 4.18.0-next-20180823+ #46
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1c9/0x2b4 lib/dump_stack.c:113
 print_circular_bug.isra.34.cold.55+0x1bd/0x27d kernel/locking/lockdep.c:1222
 check_prev_add kernel/locking/lockdep.c:1862 [inline]
 check_prevs_add kernel/locking/lockdep.c:1975 [inline]
 validate_chain kernel/locking/lockdep.c:2416 [inline]
 __lock_acquire+0x3449/0x5020 kernel/locking/lockdep.c:3412
 lock_acquire+0x1e4/0x4f0 kernel/locking/lockdep.c:3901
 flush_workqueue+0x30a/0x1e10 kernel/workqueue.c:2655
 drain_workqueue+0x2a9/0x640 kernel/workqueue.c:2820
 destroy_workqueue+0xc6/0x9d0 kernel/workqueue.c:4155
 __alloc_workqueue_key+0xef9/0x1190 kernel/workqueue.c:4138
 bond_init+0x269/0x940 drivers/net/bonding/bond_main.c:4734
 register_netdevice+0x337/0x1100 net/core/dev.c:8410
 bond_newlink+0x49/0xa0 drivers/net/bonding/bond_netlink.c:453
 rtnl_newlink+0xef4/0x1d50 net/core/rtnetlink.c:3099
 rtnetlink_rcv_msg+0x46e/0xc30 net/core/rtnetlink.c:4711
 netlink_rcv_skb+0x172/0x440 net/netlink/af_netlink.c:2454
 rtnetlink_rcv+0x1c/0x20 net/core/rtnetlink.c:4729
 netlink_unicast_kernel net/netlink/af_netlink.c:1317 [inline]
 netlink_unicast+0x5a0/0x760 net/netlink/af_netlink.c:1343
 netlink_sendmsg+0xa18/0xfc0 net/netlink/af_netlink.c:1908
 sock_sendmsg_nosec net/socket.c:622 [inline]
 sock_sendmsg+0xd5/0x120 net/socket.c:632
 ___sys_sendmsg+0x7fd/0x930 net/socket.c:2115
 __sys_sendmsg+0x11d/0x290 net/socket.c:2153
 __do_sys_sendmsg net/socket.c:2162 [inline]
 __se_sys_sendmsg net/socket.c:2160 [inline]
 __x64_sys_sendmsg+0x78/0xb0 net/socket.c:2160
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x457089
Code: fd b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 &lt;48&gt; 3d 01 f0 ff ff 0f 83 cb b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f2df20a5c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f2df20a66d4 RCX: 0000000000457089
RDX: 0000000000000000 RSI: 0000000020000180 RDI: 0000000000000003
RBP: 0000000000930140 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000004d40b8 R14: 00000000004c8ad8 R15: 0000000000000001

Signed-off-by: Mahesh Bandewar &lt;maheshb@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>
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