<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-toradex.git/net/hsr/hsr_netlink.c, branch v6.9</title>
<subtitle>Linux kernel for Apalis and Colibri modules</subtitle>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/'/>
<entry>
<title>Revert "net: hsr: use hlist_head instead of list_head for mac addresses"</title>
<updated>2022-12-02T04:26:20+00:00</updated>
<author>
<name>Sebastian Andrzej Siewior</name>
<email>bigeasy@linutronix.de</email>
</author>
<published>2022-11-29T16:48:08+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=e012764cebf6e33097f6833ff15a936fbe7b846c'/>
<id>e012764cebf6e33097f6833ff15a936fbe7b846c</id>
<content type='text'>
The hlist optimisation (which not only uses hlist_head instead of
list_head but also splits hsr_priv::node_db into an array of 256 slots)
does not consider the "node merge":
Upon starting the hsr network (with three nodes) a packet that is
sent from node1 to node3 will also be sent from node1 to node2 and then
forwarded to node3.
As a result node3 will receive 2 packets because it is not able
to filter out the duplicate. Each packet received will create a new
struct hsr_node with macaddress_A only set the MAC address it received
from (the two MAC addesses from node1).
At some point (early in the process) two supervision frames will be
received from node1. They will be processed by hsr_handle_sup_frame()
and one frame will leave early ("Node has already been merged") and does
nothing. The other frame will be merged as portB and have its MAC
address written to macaddress_B and the hsr_node (that was created for
it as macaddress_A) will be removed.
From now on HSR is able to identify a duplicate because both packets
sent from one node will result in the same struct hsr_node because
hsr_get_node() will find the MAC address either on macaddress_A or
macaddress_B.

Things get tricky with the optimisation: If sender's MAC address is
saved as macaddress_A then the lookup will work as usual. If the MAC
address has been merged into macaddress_B of another hsr_node then the
lookup won't work because it is likely that the data structure is in
another bucket. This results in creating a new struct hsr_node and not
recognising a possible duplicate.

A way around it would be to add another hsr_node::mac_list_B and attach
it to the other bucket to ensure that this hsr_node will be looked up
either via macaddress_A _or_ macaddress_B.

I however prefer to revert it because it sounds like an academic problem
rather than real life workload plus it adds complexity. I'm not an HSR
expert with what is usual size of a network but I would guess 40 to 60
nodes. With 10.000 nodes and assuming 60us for pass-through (from node
to node) then it would take almost 600ms for a packet to almost wrap
around which sounds a lot.

Revert the hash MAC addresses optimisation.

Fixes: 4acc45db71158 ("net: hsr: use hlist_head instead of list_head for mac addresses")
Cc: Juhee Kang &lt;claudiajkang@gmail.com&gt;
Signed-off-by: Sebastian Andrzej Siewior &lt;bigeasy@linutronix.de&gt;
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The hlist optimisation (which not only uses hlist_head instead of
list_head but also splits hsr_priv::node_db into an array of 256 slots)
does not consider the "node merge":
Upon starting the hsr network (with three nodes) a packet that is
sent from node1 to node3 will also be sent from node1 to node2 and then
forwarded to node3.
As a result node3 will receive 2 packets because it is not able
to filter out the duplicate. Each packet received will create a new
struct hsr_node with macaddress_A only set the MAC address it received
from (the two MAC addesses from node1).
At some point (early in the process) two supervision frames will be
received from node1. They will be processed by hsr_handle_sup_frame()
and one frame will leave early ("Node has already been merged") and does
nothing. The other frame will be merged as portB and have its MAC
address written to macaddress_B and the hsr_node (that was created for
it as macaddress_A) will be removed.
From now on HSR is able to identify a duplicate because both packets
sent from one node will result in the same struct hsr_node because
hsr_get_node() will find the MAC address either on macaddress_A or
macaddress_B.

Things get tricky with the optimisation: If sender's MAC address is
saved as macaddress_A then the lookup will work as usual. If the MAC
address has been merged into macaddress_B of another hsr_node then the
lookup won't work because it is likely that the data structure is in
another bucket. This results in creating a new struct hsr_node and not
recognising a possible duplicate.

A way around it would be to add another hsr_node::mac_list_B and attach
it to the other bucket to ensure that this hsr_node will be looked up
either via macaddress_A _or_ macaddress_B.

I however prefer to revert it because it sounds like an academic problem
rather than real life workload plus it adds complexity. I'm not an HSR
expert with what is usual size of a network but I would guess 40 to 60
nodes. With 10.000 nodes and assuming 60us for pass-through (from node
to node) then it would take almost 600ms for a packet to almost wrap
around which sounds a lot.

Revert the hash MAC addresses optimisation.

Fixes: 4acc45db71158 ("net: hsr: use hlist_head instead of list_head for mac addresses")
Cc: Juhee Kang &lt;claudiajkang@gmail.com&gt;
Signed-off-by: Sebastian Andrzej Siewior &lt;bigeasy@linutronix.de&gt;
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>genetlink: start to validate reserved header bytes</title>
<updated>2022-08-29T11:47:15+00:00</updated>
<author>
<name>Jakub Kicinski</name>
<email>kuba@kernel.org</email>
</author>
<published>2022-08-25T00:18:30+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=9c5d03d362519f36cd551aec596388f895c93d2d'/>
<id>9c5d03d362519f36cd551aec596388f895c93d2d</id>
<content type='text'>
We had historically not checked that genlmsghdr.reserved
is 0 on input which prevents us from using those precious
bytes in the future.

One use case would be to extend the cmd field, which is
currently just 8 bits wide and 256 is not a lot of commands
for some core families.

To make sure that new families do the right thing by default
put the onus of opting out of validation on existing families.

Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
Acked-by: Paul Moore &lt;paul@paul-moore.com&gt; (NetLabel)
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 had historically not checked that genlmsghdr.reserved
is 0 on input which prevents us from using those precious
bytes in the future.

One use case would be to extend the cmd field, which is
currently just 8 bits wide and 256 is not a lot of commands
for some core families.

To make sure that new families do the right thing by default
put the onus of opting out of validation on existing families.

Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
Acked-by: Paul Moore &lt;paul@paul-moore.com&gt; (NetLabel)
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>net: hsr: use hlist_head instead of list_head for mac addresses</title>
<updated>2022-02-06T10:55:52+00:00</updated>
<author>
<name>Juhee Kang</name>
<email>claudiajkang@gmail.com</email>
</author>
<published>2022-02-05T15:40:38+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=4acc45db711586dadb98e681ccb93f29372907a2'/>
<id>4acc45db711586dadb98e681ccb93f29372907a2</id>
<content type='text'>
Currently, HSR manages mac addresses of known HSR nodes by using list_head.
It takes a lot of time when there are a lot of registered nodes due to
finding specific mac address nodes by using linear search. We can be
reducing the time by using hlist. Thus, this patch moves list_head to
hlist_head for mac addresses and this allows for further improvement of
network performance.

    Condition: registered 10,000 known HSR nodes
    Before:
    # iperf3 -c 192.168.10.1 -i 1 -t 10
    Connecting to host 192.168.10.1, port 5201
    [  5] local 192.168.10.2 port 59442 connected to 192.168.10.1 port 5201
    [ ID] Interval           Transfer     Bitrate         Retr  Cwnd
    [  5]   0.00-1.49   sec  3.75 MBytes  21.1 Mbits/sec    0    158 KBytes
    [  5]   1.49-2.05   sec  1.25 MBytes  18.7 Mbits/sec    0    166 KBytes
    [  5]   2.05-3.06   sec  2.44 MBytes  20.3 Mbits/sec   56   16.9 KBytes
    [  5]   3.06-4.08   sec  1.43 MBytes  11.7 Mbits/sec   11   38.0 KBytes
    [  5]   4.08-5.00   sec   951 KBytes  8.49 Mbits/sec    0   56.3 KBytes

    After:
    # iperf3 -c 192.168.10.1 -i 1 -t 10
    Connecting to host 192.168.10.1, port 5201
    [  5] local 192.168.10.2 port 36460 connected to 192.168.10.1 port 5201
    [ ID] Interval           Transfer     Bitrate         Retr  Cwnd
    [  5]   0.00-1.00   sec  7.39 MBytes  62.0 Mbits/sec    3    130 KBytes
    [  5]   1.00-2.00   sec  5.06 MBytes  42.4 Mbits/sec   16    113 KBytes
    [  5]   2.00-3.00   sec  8.58 MBytes  72.0 Mbits/sec   42   94.3 KBytes
    [  5]   3.00-4.00   sec  7.44 MBytes  62.4 Mbits/sec    2    131 KBytes
    [  5]   4.00-5.07   sec  8.13 MBytes  63.5 Mbits/sec   38   92.9 KBytes

Signed-off-by: Juhee Kang &lt;claudiajkang@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>
Currently, HSR manages mac addresses of known HSR nodes by using list_head.
It takes a lot of time when there are a lot of registered nodes due to
finding specific mac address nodes by using linear search. We can be
reducing the time by using hlist. Thus, this patch moves list_head to
hlist_head for mac addresses and this allows for further improvement of
network performance.

    Condition: registered 10,000 known HSR nodes
    Before:
    # iperf3 -c 192.168.10.1 -i 1 -t 10
    Connecting to host 192.168.10.1, port 5201
    [  5] local 192.168.10.2 port 59442 connected to 192.168.10.1 port 5201
    [ ID] Interval           Transfer     Bitrate         Retr  Cwnd
    [  5]   0.00-1.49   sec  3.75 MBytes  21.1 Mbits/sec    0    158 KBytes
    [  5]   1.49-2.05   sec  1.25 MBytes  18.7 Mbits/sec    0    166 KBytes
    [  5]   2.05-3.06   sec  2.44 MBytes  20.3 Mbits/sec   56   16.9 KBytes
    [  5]   3.06-4.08   sec  1.43 MBytes  11.7 Mbits/sec   11   38.0 KBytes
    [  5]   4.08-5.00   sec   951 KBytes  8.49 Mbits/sec    0   56.3 KBytes

    After:
    # iperf3 -c 192.168.10.1 -i 1 -t 10
    Connecting to host 192.168.10.1, port 5201
    [  5] local 192.168.10.2 port 36460 connected to 192.168.10.1 port 5201
    [ ID] Interval           Transfer     Bitrate         Retr  Cwnd
    [  5]   0.00-1.00   sec  7.39 MBytes  62.0 Mbits/sec    3    130 KBytes
    [  5]   1.00-2.00   sec  5.06 MBytes  42.4 Mbits/sec   16    113 KBytes
    [  5]   2.00-3.00   sec  8.58 MBytes  72.0 Mbits/sec   42   94.3 KBytes
    [  5]   3.00-4.00   sec  7.44 MBytes  62.4 Mbits/sec    2    131 KBytes
    [  5]   4.00-5.07   sec  8.13 MBytes  63.5 Mbits/sec   38   92.9 KBytes

Signed-off-by: Juhee Kang &lt;claudiajkang@gmail.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>genetlink: move to smaller ops wherever possible</title>
<updated>2020-10-03T02:11:11+00:00</updated>
<author>
<name>Jakub Kicinski</name>
<email>kuba@kernel.org</email>
</author>
<published>2020-10-02T21:49:54+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=66a9b9287d2447a91cef2fafc648dee32186f708'/>
<id>66a9b9287d2447a91cef2fafc648dee32186f708</id>
<content type='text'>
Bulk of the genetlink users can use smaller ops, move them.

Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
Reviewed-by: Johannes Berg &lt;johannes@sipsolutions.net&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>
Bulk of the genetlink users can use smaller ops, move them.

Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
Reviewed-by: Johannes Berg &lt;johannes@sipsolutions.net&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>hsr: avoid newline at end of message in NL_SET_ERR_MSG_MOD</title>
<updated>2020-09-09T18:15:26+00:00</updated>
<author>
<name>Ye Bin</name>
<email>yebin10@huawei.com</email>
</author>
<published>2020-09-09T09:38:21+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=b87f9fe1ac9441b75656dfd95eba70ef9f0375e0'/>
<id>b87f9fe1ac9441b75656dfd95eba70ef9f0375e0</id>
<content type='text'>
clean follow coccicheck warning:
net//hsr/hsr_netlink.c:94:8-42: WARNING avoid newline at end of message
in NL_SET_ERR_MSG_MOD
net//hsr/hsr_netlink.c:87:30-57: WARNING avoid newline at end of message
in NL_SET_ERR_MSG_MOD
net//hsr/hsr_netlink.c:79:29-53: WARNING avoid newline at end of message
in NL_SET_ERR_MSG_MOD

Signed-off-by: Ye Bin &lt;yebin10@huawei.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>
clean follow coccicheck warning:
net//hsr/hsr_netlink.c:94:8-42: WARNING avoid newline at end of message
in NL_SET_ERR_MSG_MOD
net//hsr/hsr_netlink.c:87:30-57: WARNING avoid newline at end of message
in NL_SET_ERR_MSG_MOD
net//hsr/hsr_netlink.c:79:29-53: WARNING avoid newline at end of message
in NL_SET_ERR_MSG_MOD

Signed-off-by: Ye Bin &lt;yebin10@huawei.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>hsr: enhance netlink socket interface to support PRP</title>
<updated>2020-07-27T19:20:40+00:00</updated>
<author>
<name>Murali Karicheri</name>
<email>m-karicheri2@ti.com</email>
</author>
<published>2020-07-22T14:40:16+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=8f4c0e01789c18674acdf17cae3822b3dc3db715'/>
<id>8f4c0e01789c18674acdf17cae3822b3dc3db715</id>
<content type='text'>
Parallel Redundancy Protocol (PRP) is another redundancy protocol
introduced by IEC 63439 standard. It is similar to HSR in many
aspects:-

 - Use a pair of Ethernet interfaces to created the PRP device
 - Use a 6 byte redundancy protocol part (RCT, Redundancy Check
   Trailer) similar to HSR Tag.
 - Has Link Redundancy Entity (LRE) that works with RCT to implement
   redundancy.

Key difference is that the protocol unit is a trailer instead of a
prefix as in HSR. That makes it inter-operable with tradition network
components such as bridges/switches which treat it as pad bytes,
whereas HSR nodes requires some kind of translators (Called redbox) to
talk to regular network devices. This features allows regular linux box
to be converted to a DAN-P box. DAN-P stands for Dual Attached Node - PRP
similar to DAN-H (Dual Attached Node - HSR).

Add a comment at the header/source code to explicitly state that the
driver files also handles PRP protocol as well.

Signed-off-by: Murali Karicheri &lt;m-karicheri2@ti.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>
Parallel Redundancy Protocol (PRP) is another redundancy protocol
introduced by IEC 63439 standard. It is similar to HSR in many
aspects:-

 - Use a pair of Ethernet interfaces to created the PRP device
 - Use a 6 byte redundancy protocol part (RCT, Redundancy Check
   Trailer) similar to HSR Tag.
 - Has Link Redundancy Entity (LRE) that works with RCT to implement
   redundancy.

Key difference is that the protocol unit is a trailer instead of a
prefix as in HSR. That makes it inter-operable with tradition network
components such as bridges/switches which treat it as pad bytes,
whereas HSR nodes requires some kind of translators (Called redbox) to
talk to regular network devices. This features allows regular linux box
to be converted to a DAN-P box. DAN-P stands for Dual Attached Node - PRP
similar to DAN-H (Dual Attached Node - HSR).

Add a comment at the header/source code to explicitly state that the
driver files also handles PRP protocol as well.

Signed-off-by: Murali Karicheri &lt;m-karicheri2@ti.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>hsr: avoid to create proc file after unregister</title>
<updated>2020-06-23T03:42:23+00:00</updated>
<author>
<name>Taehee Yoo</name>
<email>ap420073@gmail.com</email>
</author>
<published>2020-06-21T13:46:25+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=de0083c7ed7dba036d1ed6e012157649d45313c8'/>
<id>de0083c7ed7dba036d1ed6e012157649d45313c8</id>
<content type='text'>
When an interface is being deleted, "/proc/net/dev_snmp6/&lt;interface name&gt;"
is deleted.
The function for this is addrconf_ifdown() in the addrconf_notify() and
it is called by notification, which is NETDEV_UNREGISTER.
But, if NETDEV_CHANGEMTU is triggered after NETDEV_UNREGISTER,
this proc file will be created again.
This recreated proc file will be deleted by netdev_wati_allrefs().
Before netdev_wait_allrefs() is called, creating a new HSR interface
routine can be executed and It tries to create a proc file but it will
find an un-deleted proc file.
At this point, it warns about it.

To avoid this situation, it can use -&gt;dellink() instead of
-&gt;ndo_uninit() to release resources because -&gt;dellink() is called
before NETDEV_UNREGISTER.
So, a proc file will not be recreated.

Test commands
    ip link add dummy0 type dummy
    ip link add dummy1 type dummy
    ip link set dummy0 mtu 1300

    #SHELL1
    while :
    do
        ip link add hsr0 type hsr slave1 dummy0 slave2 dummy1
    done

    #SHELL2
    while :
    do
        ip link del hsr0
    done

Splat looks like:
[ 9888.980852][ T2752] proc_dir_entry 'dev_snmp6/hsr0' already registered
[ 9888.981797][    C2] WARNING: CPU: 2 PID: 2752 at fs/proc/generic.c:372 proc_register+0x2d5/0x430
[ 9888.981798][    C2] Modules linked in: hsr dummy veth openvswitch nsh nf_conncount nf_nat nf_conntrack nf_defrag_ipv6x
[ 9888.981814][    C2] CPU: 2 PID: 2752 Comm: ip Tainted: G        W         5.8.0-rc1+ #616
[ 9888.981815][    C2] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006
[ 9888.981816][    C2] RIP: 0010:proc_register+0x2d5/0x430
[ 9888.981818][    C2] Code: fc ff df 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 65 01 00 00 49 8b b5 e0 00 00 00 48 89 ea 40
[ 9888.981819][    C2] RSP: 0018:ffff8880628dedf0 EFLAGS: 00010286
[ 9888.981821][    C2] RAX: dffffc0000000008 RBX: ffff888028c69170 RCX: ffffffffaae09a62
[ 9888.981822][    C2] RDX: 0000000000000001 RSI: 0000000000000008 RDI: ffff88806c9f75ac
[ 9888.981823][    C2] RBP: ffff888028c693f4 R08: ffffed100d9401bd R09: ffffed100d9401bd
[ 9888.981824][    C2] R10: ffffffffaddf406f R11: 0000000000000001 R12: ffff888028c69308
[ 9888.981825][    C2] R13: ffff8880663584c8 R14: dffffc0000000000 R15: ffffed100518d27e
[ 9888.981827][    C2] FS:  00007f3876b3b0c0(0000) GS:ffff88806c800000(0000) knlGS:0000000000000000
[ 9888.981828][    C2] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 9888.981829][    C2] CR2: 00007f387601a8c0 CR3: 000000004101a002 CR4: 00000000000606e0
[ 9888.981830][    C2] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 9888.981831][    C2] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 9888.981832][    C2] Call Trace:
[ 9888.981833][    C2]  ? snmp6_seq_show+0x180/0x180
[ 9888.981834][    C2]  proc_create_single_data+0x7c/0xa0
[ 9888.981835][    C2]  snmp6_register_dev+0xb0/0x130
[ 9888.981836][    C2]  ipv6_add_dev+0x4b7/0xf60
[ 9888.981837][    C2]  addrconf_notify+0x684/0x1ca0
[ 9888.981838][    C2]  ? __mutex_unlock_slowpath+0xd0/0x670
[ 9888.981839][    C2]  ? kasan_unpoison_shadow+0x30/0x40
[ 9888.981840][    C2]  ? wait_for_completion+0x250/0x250
[ 9888.981841][    C2]  ? inet6_ifinfo_notify+0x100/0x100
[ 9888.981842][    C2]  ? dropmon_net_event+0x227/0x410
[ 9888.981843][    C2]  ? notifier_call_chain+0x90/0x160
[ 9888.981844][    C2]  ? inet6_ifinfo_notify+0x100/0x100
[ 9888.981845][    C2]  notifier_call_chain+0x90/0x160
[ 9888.981846][    C2]  register_netdevice+0xbe5/0x1070
[ ... ]

Reported-by: syzbot+1d51c8b74efa4c44adeb@syzkaller.appspotmail.com
Fixes: e0a4b99773d3 ("hsr: use upper/lower device infrastructure")
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 an interface is being deleted, "/proc/net/dev_snmp6/&lt;interface name&gt;"
is deleted.
The function for this is addrconf_ifdown() in the addrconf_notify() and
it is called by notification, which is NETDEV_UNREGISTER.
But, if NETDEV_CHANGEMTU is triggered after NETDEV_UNREGISTER,
this proc file will be created again.
This recreated proc file will be deleted by netdev_wati_allrefs().
Before netdev_wait_allrefs() is called, creating a new HSR interface
routine can be executed and It tries to create a proc file but it will
find an un-deleted proc file.
At this point, it warns about it.

To avoid this situation, it can use -&gt;dellink() instead of
-&gt;ndo_uninit() to release resources because -&gt;dellink() is called
before NETDEV_UNREGISTER.
So, a proc file will not be recreated.

Test commands
    ip link add dummy0 type dummy
    ip link add dummy1 type dummy
    ip link set dummy0 mtu 1300

    #SHELL1
    while :
    do
        ip link add hsr0 type hsr slave1 dummy0 slave2 dummy1
    done

    #SHELL2
    while :
    do
        ip link del hsr0
    done

Splat looks like:
[ 9888.980852][ T2752] proc_dir_entry 'dev_snmp6/hsr0' already registered
[ 9888.981797][    C2] WARNING: CPU: 2 PID: 2752 at fs/proc/generic.c:372 proc_register+0x2d5/0x430
[ 9888.981798][    C2] Modules linked in: hsr dummy veth openvswitch nsh nf_conncount nf_nat nf_conntrack nf_defrag_ipv6x
[ 9888.981814][    C2] CPU: 2 PID: 2752 Comm: ip Tainted: G        W         5.8.0-rc1+ #616
[ 9888.981815][    C2] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006
[ 9888.981816][    C2] RIP: 0010:proc_register+0x2d5/0x430
[ 9888.981818][    C2] Code: fc ff df 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 65 01 00 00 49 8b b5 e0 00 00 00 48 89 ea 40
[ 9888.981819][    C2] RSP: 0018:ffff8880628dedf0 EFLAGS: 00010286
[ 9888.981821][    C2] RAX: dffffc0000000008 RBX: ffff888028c69170 RCX: ffffffffaae09a62
[ 9888.981822][    C2] RDX: 0000000000000001 RSI: 0000000000000008 RDI: ffff88806c9f75ac
[ 9888.981823][    C2] RBP: ffff888028c693f4 R08: ffffed100d9401bd R09: ffffed100d9401bd
[ 9888.981824][    C2] R10: ffffffffaddf406f R11: 0000000000000001 R12: ffff888028c69308
[ 9888.981825][    C2] R13: ffff8880663584c8 R14: dffffc0000000000 R15: ffffed100518d27e
[ 9888.981827][    C2] FS:  00007f3876b3b0c0(0000) GS:ffff88806c800000(0000) knlGS:0000000000000000
[ 9888.981828][    C2] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 9888.981829][    C2] CR2: 00007f387601a8c0 CR3: 000000004101a002 CR4: 00000000000606e0
[ 9888.981830][    C2] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 9888.981831][    C2] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 9888.981832][    C2] Call Trace:
[ 9888.981833][    C2]  ? snmp6_seq_show+0x180/0x180
[ 9888.981834][    C2]  proc_create_single_data+0x7c/0xa0
[ 9888.981835][    C2]  snmp6_register_dev+0xb0/0x130
[ 9888.981836][    C2]  ipv6_add_dev+0x4b7/0xf60
[ 9888.981837][    C2]  addrconf_notify+0x684/0x1ca0
[ 9888.981838][    C2]  ? __mutex_unlock_slowpath+0xd0/0x670
[ 9888.981839][    C2]  ? kasan_unpoison_shadow+0x30/0x40
[ 9888.981840][    C2]  ? wait_for_completion+0x250/0x250
[ 9888.981841][    C2]  ? inet6_ifinfo_notify+0x100/0x100
[ 9888.981842][    C2]  ? dropmon_net_event+0x227/0x410
[ 9888.981843][    C2]  ? notifier_call_chain+0x90/0x160
[ 9888.981844][    C2]  ? inet6_ifinfo_notify+0x100/0x100
[ 9888.981845][    C2]  notifier_call_chain+0x90/0x160
[ 9888.981846][    C2]  register_netdevice+0xbe5/0x1070
[ ... ]

Reported-by: syzbot+1d51c8b74efa4c44adeb@syzkaller.appspotmail.com
Fixes: e0a4b99773d3 ("hsr: use upper/lower device infrastructure")
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>hsr: check protocol version in hsr_newlink()</title>
<updated>2020-04-08T01:34:18+00:00</updated>
<author>
<name>Taehee Yoo</name>
<email>ap420073@gmail.com</email>
</author>
<published>2020-04-07T13:23:21+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=4faab8c446def7667adf1f722456c2f4c304069c'/>
<id>4faab8c446def7667adf1f722456c2f4c304069c</id>
<content type='text'>
In the current hsr code, only 0 and 1 protocol versions are valid.
But current hsr code doesn't check the version, which is received by
userspace.

Test commands:
    ip link add dummy0 type dummy
    ip link add dummy1 type dummy
    ip link add hsr0 type hsr slave1 dummy0 slave2 dummy1 version 4

In the test commands, version 4 is invalid.
So, the command should be failed.

After this patch, following error will occur.
"Error: hsr: Only versions 0..1 are supported."

Fixes: ee1c27977284 ("net/hsr: Added support for HSR v1")
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>
In the current hsr code, only 0 and 1 protocol versions are valid.
But current hsr code doesn't check the version, which is received by
userspace.

Test commands:
    ip link add dummy0 type dummy
    ip link add dummy1 type dummy
    ip link add hsr0 type hsr slave1 dummy0 slave2 dummy1 version 4

In the test commands, version 4 is invalid.
So, the command should be failed.

After this patch, following error will occur.
"Error: hsr: Only versions 0..1 are supported."

Fixes: ee1c27977284 ("net/hsr: Added support for HSR v1")
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>Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net</title>
<updated>2020-03-26T01:58:11+00:00</updated>
<author>
<name>David S. Miller</name>
<email>davem@davemloft.net</email>
</author>
<published>2020-03-26T01:58:11+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=9fb16955fb661945ddffce4504dcffbe55cd518a'/>
<id>9fb16955fb661945ddffce4504dcffbe55cd518a</id>
<content type='text'>
Overlapping header include additions in macsec.c

A bug fix in 'net' overlapping with the removal of 'version'
string in ena_netdev.c

Overlapping test additions in selftests Makefile

Overlapping PCI ID table adjustments in iwlwifi driver.

Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Overlapping header include additions in macsec.c

A bug fix in 'net' overlapping with the removal of 'version'
string in ena_netdev.c

Overlapping test additions in selftests Makefile

Overlapping PCI ID table adjustments in iwlwifi driver.

Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>hsr: set .netnsok flag</title>
<updated>2020-03-16T08:46:09+00:00</updated>
<author>
<name>Taehee Yoo</name>
<email>ap420073@gmail.com</email>
</author>
<published>2020-03-13T06:50:33+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=09e91dbea0aa32be02d8877bd50490813de56b9a'/>
<id>09e91dbea0aa32be02d8877bd50490813de56b9a</id>
<content type='text'>
The hsr module has been supporting the list and status command.
(HSR_C_GET_NODE_LIST and HSR_C_GET_NODE_STATUS)
These commands send node information to the user-space via generic netlink.
But, in the non-init_net namespace, these commands are not allowed
because .netnsok flag is false.
So, there is no way to get node information in the non-init_net namespace.

Fixes: f421436a591d ("net/hsr: Add support for the High-availability Seamless Redundancy protocol (HSRv0)")
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>
The hsr module has been supporting the list and status command.
(HSR_C_GET_NODE_LIST and HSR_C_GET_NODE_STATUS)
These commands send node information to the user-space via generic netlink.
But, in the non-init_net namespace, these commands are not allowed
because .netnsok flag is false.
So, there is no way to get node information in the non-init_net namespace.

Fixes: f421436a591d ("net/hsr: Add support for the High-availability Seamless Redundancy protocol (HSRv0)")
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>
</feed>
