<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/net/tipc/discover.c, branch linux-5.4.y</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>tipc: simplify the finalize work queue</title>
<updated>2025-12-03T11:45:17+00:00</updated>
<author>
<name>Xin Long</name>
<email>lucien.xin@gmail.com</email>
</author>
<published>2021-05-18T02:09:08+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=201fee25fd2018f7c31331f85ee7a2f2e3d03c52'/>
<id>201fee25fd2018f7c31331f85ee7a2f2e3d03c52</id>
<content type='text'>
[ Upstream commit be07f056396d6bb40963c45a02951c566ddeef8e ]

This patch is to use "struct work_struct" for the finalize work queue
instead of "struct tipc_net_work", as it can get the "net" and "addr"
from tipc_net's other members and there is no need to add extra net
and addr in tipc_net by defining "struct tipc_net_work".

Note that it's safe to get net from tn-&gt;bcl as bcl is always released
after the finalize work queue is done.

Signed-off-by: Xin Long &lt;lucien.xin@gmail.com&gt;
Acked-by: Jon Maloy &lt;jmaloy@redhat.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Stable-dep-of: 0725e6afb551 ("tipc: Fix use-after-free in tipc_mon_reinit_self().")
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 be07f056396d6bb40963c45a02951c566ddeef8e ]

This patch is to use "struct work_struct" for the finalize work queue
instead of "struct tipc_net_work", as it can get the "net" and "addr"
from tipc_net's other members and there is no need to add extra net
and addr in tipc_net by defining "struct tipc_net_work".

Note that it's safe to get net from tn-&gt;bcl as bcl is always released
after the finalize work queue is done.

Signed-off-by: Xin Long &lt;lucien.xin@gmail.com&gt;
Acked-by: Jon Maloy &lt;jmaloy@redhat.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Stable-dep-of: 0725e6afb551 ("tipc: Fix use-after-free in tipc_mon_reinit_self().")
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>tipc: fix use-after-free in tipc_disc_rcv()</title>
<updated>2023-01-18T10:42:06+00:00</updated>
<author>
<name>Tuong Lien</name>
<email>tuong.t.lien@dektech.com.au</email>
</author>
<published>2019-12-10T08:21:05+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=3188f80b80d62823d3e3a6539b5216dd89e6250c'/>
<id>3188f80b80d62823d3e3a6539b5216dd89e6250c</id>
<content type='text'>
commit 31e4ccc99eda8a5a7e6902c98bee6e78ffd3edb9 upstream.

In the function 'tipc_disc_rcv()', the 'msg_peer_net_hash()' is called
to read the header data field but after the message skb has been freed,
that might result in a garbage value...

This commit fixes it by defining a new local variable to store the data
first, just like the other header fields' handling.

Fixes: f73b12812a3d ("tipc: improve throughput between nodes in netns")
Acked-by: Jon Maloy &lt;jon.maloy@ericsson.com&gt;
Signed-off-by: Tuong Lien &lt;tuong.t.lien@dektech.com.au&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>
commit 31e4ccc99eda8a5a7e6902c98bee6e78ffd3edb9 upstream.

In the function 'tipc_disc_rcv()', the 'msg_peer_net_hash()' is called
to read the header data field but after the message skb has been freed,
that might result in a garbage value...

This commit fixes it by defining a new local variable to store the data
first, just like the other header fields' handling.

Fixes: f73b12812a3d ("tipc: improve throughput between nodes in netns")
Acked-by: Jon Maloy &lt;jon.maloy@ericsson.com&gt;
Signed-off-by: Tuong Lien &lt;tuong.t.lien@dektech.com.au&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>tipc: improve throughput between nodes in netns</title>
<updated>2023-01-18T10:42:04+00:00</updated>
<author>
<name>Hoang Le</name>
<email>hoang.h.le@dektech.com.au</email>
</author>
<published>2019-10-29T00:51:21+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=d6418829cef16eba10fdcf928009575c647f16e9'/>
<id>d6418829cef16eba10fdcf928009575c647f16e9</id>
<content type='text'>
[ Upstream commit f73b12812a3d1d798b7517547ccdcf864844d2cd ]

Currently, TIPC transports intra-node user data messages directly
socket to socket, hence shortcutting all the lower layers of the
communication stack. This gives TIPC very good intra node performance,
both regarding throughput and latency.

We now introduce a similar mechanism for TIPC data traffic across
network namespaces located in the same kernel. On the send path, the
call chain is as always accompanied by the sending node's network name
space pointer. However, once we have reliably established that the
receiving node is represented by a namespace on the same host, we just
replace the namespace pointer with the receiving node/namespace's
ditto, and follow the regular socket receive patch though the receiving
node. This technique gives us a throughput similar to the node internal
throughput, several times larger than if we let the traffic go though
the full network stacks. As a comparison, max throughput for 64k
messages is four times larger than TCP throughput for the same type of
traffic.

To meet any security concerns, the following should be noted.

- All nodes joining a cluster are supposed to have been be certified
and authenticated by mechanisms outside TIPC. This is no different for
nodes/namespaces on the same host; they have to auto discover each
other using the attached interfaces, and establish links which are
supervised via the regular link monitoring mechanism. Hence, a kernel
local node has no other way to join a cluster than any other node, and
have to obey to policies set in the IP or device layers of the stack.

- Only when a sender has established with 100% certainty that the peer
node is located in a kernel local namespace does it choose to let user
data messages, and only those, take the crossover path to the receiving
node/namespace.

- If the receiving node/namespace is removed, its namespace pointer
is invalidated at all peer nodes, and their neighbor link monitoring
will eventually note that this node is gone.

- To ensure the "100% certainty" criteria, and prevent any possible
spoofing, received discovery messages must contain a proof that the
sender knows a common secret. We use the hash mix of the sending
node/namespace for this purpose, since it can be accessed directly by
all other namespaces in the kernel. Upon reception of a discovery
message, the receiver checks this proof against all the local
namespaces'hash_mix:es. If it finds a match, that, along with a
matching node id and cluster id, this is deemed sufficient proof that
the peer node in question is in a local namespace, and a wormhole can
be opened.

- We should also consider that TIPC is intended to be a cluster local
IPC mechanism (just like e.g. UNIX sockets) rather than a network
protocol, and hence we think it can justified to allow it to shortcut the
lower protocol layers.

Regarding traceability, we should notice that since commit 6c9081a3915d
("tipc: add loopback device tracking") it is possible to follow the node
internal packet flow by just activating tcpdump on the loopback
interface. This will be true even for this mechanism; by activating
tcpdump on the involved nodes' loopback interfaces their inter-name
space messaging can easily be tracked.

v2:
- update 'net' pointer when node left/rejoined
v3:
- grab read/write lock when using node ref obj
v4:
- clone traffics between netns to loopback

Suggested-by: Jon Maloy &lt;jon.maloy@ericsson.com&gt;
Acked-by: Jon Maloy &lt;jon.maloy@ericsson.com&gt;
Signed-off-by: Hoang Le &lt;hoang.h.le@dektech.com.au&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Stable-dep-of: c244c092f1ed ("tipc: fix unexpected link reset due to discovery messages")
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 f73b12812a3d1d798b7517547ccdcf864844d2cd ]

Currently, TIPC transports intra-node user data messages directly
socket to socket, hence shortcutting all the lower layers of the
communication stack. This gives TIPC very good intra node performance,
both regarding throughput and latency.

We now introduce a similar mechanism for TIPC data traffic across
network namespaces located in the same kernel. On the send path, the
call chain is as always accompanied by the sending node's network name
space pointer. However, once we have reliably established that the
receiving node is represented by a namespace on the same host, we just
replace the namespace pointer with the receiving node/namespace's
ditto, and follow the regular socket receive patch though the receiving
node. This technique gives us a throughput similar to the node internal
throughput, several times larger than if we let the traffic go though
the full network stacks. As a comparison, max throughput for 64k
messages is four times larger than TCP throughput for the same type of
traffic.

To meet any security concerns, the following should be noted.

- All nodes joining a cluster are supposed to have been be certified
and authenticated by mechanisms outside TIPC. This is no different for
nodes/namespaces on the same host; they have to auto discover each
other using the attached interfaces, and establish links which are
supervised via the regular link monitoring mechanism. Hence, a kernel
local node has no other way to join a cluster than any other node, and
have to obey to policies set in the IP or device layers of the stack.

- Only when a sender has established with 100% certainty that the peer
node is located in a kernel local namespace does it choose to let user
data messages, and only those, take the crossover path to the receiving
node/namespace.

- If the receiving node/namespace is removed, its namespace pointer
is invalidated at all peer nodes, and their neighbor link monitoring
will eventually note that this node is gone.

- To ensure the "100% certainty" criteria, and prevent any possible
spoofing, received discovery messages must contain a proof that the
sender knows a common secret. We use the hash mix of the sending
node/namespace for this purpose, since it can be accessed directly by
all other namespaces in the kernel. Upon reception of a discovery
message, the receiver checks this proof against all the local
namespaces'hash_mix:es. If it finds a match, that, along with a
matching node id and cluster id, this is deemed sufficient proof that
the peer node in question is in a local namespace, and a wormhole can
be opened.

- We should also consider that TIPC is intended to be a cluster local
IPC mechanism (just like e.g. UNIX sockets) rather than a network
protocol, and hence we think it can justified to allow it to shortcut the
lower protocol layers.

Regarding traceability, we should notice that since commit 6c9081a3915d
("tipc: add loopback device tracking") it is possible to follow the node
internal packet flow by just activating tcpdump on the loopback
interface. This will be true even for this mechanism; by activating
tcpdump on the involved nodes' loopback interfaces their inter-name
space messaging can easily be tracked.

v2:
- update 'net' pointer when node left/rejoined
v3:
- grab read/write lock when using node ref obj
v4:
- clone traffics between netns to loopback

Suggested-by: Jon Maloy &lt;jon.maloy@ericsson.com&gt;
Acked-by: Jon Maloy &lt;jon.maloy@ericsson.com&gt;
Signed-off-by: Hoang Le &lt;hoang.h.le@dektech.com.au&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Stable-dep-of: c244c092f1ed ("tipc: fix unexpected link reset due to discovery messages")
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>tipc: check skb_linearize() return value in tipc_disc_rcv()</title>
<updated>2022-12-08T10:22:58+00:00</updated>
<author>
<name>YueHaibing</name>
<email>yuehaibing@huawei.com</email>
</author>
<published>2022-11-19T07:28:32+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=23ba1997ebc0d2183fc4e87f8038fa3457e0106e'/>
<id>23ba1997ebc0d2183fc4e87f8038fa3457e0106e</id>
<content type='text'>
[ Upstream commit cd0f6421162201e4b22ce757a1966729323185eb ]

If skb_linearize() fails in tipc_disc_rcv(), we need to free the skb instead of
handle it.

Fixes: 25b0b9c4e835 ("tipc: handle collisions of 32-bit node address hash values")
Signed-off-by: YueHaibing &lt;yuehaibing@huawei.com&gt;
Acked-by: Jon Maloy &lt;jmaloy@redhat.com&gt;
Link: https://lore.kernel.org/r/20221119072832.7896-1-yuehaibing@huawei.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&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 cd0f6421162201e4b22ce757a1966729323185eb ]

If skb_linearize() fails in tipc_disc_rcv(), we need to free the skb instead of
handle it.

Fixes: 25b0b9c4e835 ("tipc: handle collisions of 32-bit node address hash values")
Signed-off-by: YueHaibing &lt;yuehaibing@huawei.com&gt;
Acked-by: Jon Maloy &lt;jmaloy@redhat.com&gt;
Link: https://lore.kernel.org/r/20221119072832.7896-1-yuehaibing@huawei.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>tipc: Fix recognition of trial period</title>
<updated>2022-10-29T08:20:35+00:00</updated>
<author>
<name>Mark Tomlinson</name>
<email>mark.tomlinson@alliedtelesis.co.nz</email>
</author>
<published>2022-10-10T02:46:13+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=27ee73c1199e0a8fec0784f4aa333ebb022e7348'/>
<id>27ee73c1199e0a8fec0784f4aa333ebb022e7348</id>
<content type='text'>
[ Upstream commit 28be7ca4fcfd69a2d52aaa331adbf9dbe91f9e6e ]

The trial period exists until jiffies is after addr_trial_end. But as
jiffies will eventually overflow, just using time_after will eventually
give incorrect results. As the node address is set once the trial period
ends, this can be used to know that we are not in the trial period.

Fixes: e415577f57f4 ("tipc: correct discovery message handling during address trial period")
Signed-off-by: Mark Tomlinson &lt;mark.tomlinson@alliedtelesis.co.nz&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 28be7ca4fcfd69a2d52aaa331adbf9dbe91f9e6e ]

The trial period exists until jiffies is after addr_trial_end. But as
jiffies will eventually overflow, just using time_after will eventually
give incorrect results. As the node address is set once the trial period
ends, this can be used to know that we are not in the trial period.

Fixes: e415577f57f4 ("tipc: correct discovery message handling during address trial period")
Signed-off-by: Mark Tomlinson &lt;mark.tomlinson@alliedtelesis.co.nz&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>tipc: fix lockdep warning when reinitilaizing sockets</title>
<updated>2018-11-18T06:01:31+00:00</updated>
<author>
<name>Jon Maloy</name>
<email>donmalo99@gmail.com</email>
</author>
<published>2018-11-16T21:55:04+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=adba75be0d23cca92a028749d92c60c8909bbdb3'/>
<id>adba75be0d23cca92a028749d92c60c8909bbdb3</id>
<content type='text'>
We get the following warning:

[   47.926140] 32-bit node address hash set to 2010a0a
[   47.927202]
[   47.927433] ================================
[   47.928050] WARNING: inconsistent lock state
[   47.928661] 4.19.0+ #37 Tainted: G            E
[   47.929346] --------------------------------
[   47.929954] inconsistent {SOFTIRQ-ON-W} -&gt; {IN-SOFTIRQ-W} usage.
[   47.930116] swapper/3/0 [HC0[0]:SC1[3]:HE1:SE0] takes:
[   47.930116] 00000000af8bc31e (&amp;(&amp;ht-&gt;lock)-&gt;rlock){+.?.}, at: rhashtable_walk_enter+0x36/0xb0
[   47.930116] {SOFTIRQ-ON-W} state was registered at:
[   47.930116]   _raw_spin_lock+0x29/0x60
[   47.930116]   rht_deferred_worker+0x556/0x810
[   47.930116]   process_one_work+0x1f5/0x540
[   47.930116]   worker_thread+0x64/0x3e0
[   47.930116]   kthread+0x112/0x150
[   47.930116]   ret_from_fork+0x3a/0x50
[   47.930116] irq event stamp: 14044
[   47.930116] hardirqs last  enabled at (14044): [&lt;ffffffff9a07fbba&gt;] __local_bh_enable_ip+0x7a/0xf0
[   47.938117] hardirqs last disabled at (14043): [&lt;ffffffff9a07fb81&gt;] __local_bh_enable_ip+0x41/0xf0
[   47.938117] softirqs last  enabled at (14028): [&lt;ffffffff9a0803ee&gt;] irq_enter+0x5e/0x60
[   47.938117] softirqs last disabled at (14029): [&lt;ffffffff9a0804a5&gt;] irq_exit+0xb5/0xc0
[   47.938117]
[   47.938117] other info that might help us debug this:
[   47.938117]  Possible unsafe locking scenario:
[   47.938117]
[   47.938117]        CPU0
[   47.938117]        ----
[   47.938117]   lock(&amp;(&amp;ht-&gt;lock)-&gt;rlock);
[   47.938117]   &lt;Interrupt&gt;
[   47.938117]     lock(&amp;(&amp;ht-&gt;lock)-&gt;rlock);
[   47.938117]
[   47.938117]  *** DEADLOCK ***
[   47.938117]
[   47.938117] 2 locks held by swapper/3/0:
[   47.938117]  #0: 0000000062c64f90 ((&amp;d-&gt;timer)){+.-.}, at: call_timer_fn+0x5/0x280
[   47.938117]  #1: 00000000ee39619c (&amp;(&amp;d-&gt;lock)-&gt;rlock){+.-.}, at: tipc_disc_timeout+0xc8/0x540 [tipc]
[   47.938117]
[   47.938117] stack backtrace:
[   47.938117] CPU: 3 PID: 0 Comm: swapper/3 Tainted: G            E     4.19.0+ #37
[   47.938117] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[   47.938117] Call Trace:
[   47.938117]  &lt;IRQ&gt;
[   47.938117]  dump_stack+0x5e/0x8b
[   47.938117]  print_usage_bug+0x1ed/0x1ff
[   47.938117]  mark_lock+0x5b5/0x630
[   47.938117]  __lock_acquire+0x4c0/0x18f0
[   47.938117]  ? lock_acquire+0xa6/0x180
[   47.938117]  lock_acquire+0xa6/0x180
[   47.938117]  ? rhashtable_walk_enter+0x36/0xb0
[   47.938117]  _raw_spin_lock+0x29/0x60
[   47.938117]  ? rhashtable_walk_enter+0x36/0xb0
[   47.938117]  rhashtable_walk_enter+0x36/0xb0
[   47.938117]  tipc_sk_reinit+0xb0/0x410 [tipc]
[   47.938117]  ? mark_held_locks+0x6f/0x90
[   47.938117]  ? __local_bh_enable_ip+0x7a/0xf0
[   47.938117]  ? lockdep_hardirqs_on+0x20/0x1a0
[   47.938117]  tipc_net_finalize+0xbf/0x180 [tipc]
[   47.938117]  tipc_disc_timeout+0x509/0x540 [tipc]
[   47.938117]  ? call_timer_fn+0x5/0x280
[   47.938117]  ? tipc_disc_msg_xmit.isra.19+0xa0/0xa0 [tipc]
[   47.938117]  ? tipc_disc_msg_xmit.isra.19+0xa0/0xa0 [tipc]
[   47.938117]  call_timer_fn+0xa1/0x280
[   47.938117]  ? tipc_disc_msg_xmit.isra.19+0xa0/0xa0 [tipc]
[   47.938117]  run_timer_softirq+0x1f2/0x4d0
[   47.938117]  __do_softirq+0xfc/0x413
[   47.938117]  irq_exit+0xb5/0xc0
[   47.938117]  smp_apic_timer_interrupt+0xac/0x210
[   47.938117]  apic_timer_interrupt+0xf/0x20
[   47.938117]  &lt;/IRQ&gt;
[   47.938117] RIP: 0010:default_idle+0x1c/0x140
[   47.938117] Code: 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1f 44 00 00 41 54 55 53 65 8b 2d d8 2b 74 65 0f 1f 44 00 00 e8 c6 2c 8b ff fb f4 &lt;65&gt; 8b 2d c5 2b 74 65 0f 1f 44 00 00 5b 5d 41 5c c3 65 8b 05 b4 2b
[   47.938117] RSP: 0018:ffffaf6ac0207ec8 EFLAGS: 00000206 ORIG_RAX: ffffffffffffff13
[   47.938117] RAX: ffff8f5b3735e200 RBX: 0000000000000003 RCX: 0000000000000001
[   47.938117] RDX: 0000000000000001 RSI: 0000000000000001 RDI: ffff8f5b3735e200
[   47.938117] RBP: 0000000000000003 R08: 0000000000000001 R09: 0000000000000000
[   47.938117] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
[   47.938117] R13: 0000000000000000 R14: ffff8f5b3735e200 R15: ffff8f5b3735e200
[   47.938117]  ? default_idle+0x1a/0x140
[   47.938117]  do_idle+0x1bc/0x280
[   47.938117]  cpu_startup_entry+0x19/0x20
[   47.938117]  start_secondary+0x187/0x1c0
[   47.938117]  secondary_startup_64+0xa4/0xb0

The reason seems to be that tipc_net_finalize()-&gt;tipc_sk_reinit() is
calling the function rhashtable_walk_enter() within a timer interrupt.
We fix this by executing tipc_net_finalize() in work queue context.

Acked-by: Ying Xue &lt;ying.xue@windriver.com&gt;
Signed-off-by: Jon Maloy &lt;jon.maloy@ericsson.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 get the following warning:

[   47.926140] 32-bit node address hash set to 2010a0a
[   47.927202]
[   47.927433] ================================
[   47.928050] WARNING: inconsistent lock state
[   47.928661] 4.19.0+ #37 Tainted: G            E
[   47.929346] --------------------------------
[   47.929954] inconsistent {SOFTIRQ-ON-W} -&gt; {IN-SOFTIRQ-W} usage.
[   47.930116] swapper/3/0 [HC0[0]:SC1[3]:HE1:SE0] takes:
[   47.930116] 00000000af8bc31e (&amp;(&amp;ht-&gt;lock)-&gt;rlock){+.?.}, at: rhashtable_walk_enter+0x36/0xb0
[   47.930116] {SOFTIRQ-ON-W} state was registered at:
[   47.930116]   _raw_spin_lock+0x29/0x60
[   47.930116]   rht_deferred_worker+0x556/0x810
[   47.930116]   process_one_work+0x1f5/0x540
[   47.930116]   worker_thread+0x64/0x3e0
[   47.930116]   kthread+0x112/0x150
[   47.930116]   ret_from_fork+0x3a/0x50
[   47.930116] irq event stamp: 14044
[   47.930116] hardirqs last  enabled at (14044): [&lt;ffffffff9a07fbba&gt;] __local_bh_enable_ip+0x7a/0xf0
[   47.938117] hardirqs last disabled at (14043): [&lt;ffffffff9a07fb81&gt;] __local_bh_enable_ip+0x41/0xf0
[   47.938117] softirqs last  enabled at (14028): [&lt;ffffffff9a0803ee&gt;] irq_enter+0x5e/0x60
[   47.938117] softirqs last disabled at (14029): [&lt;ffffffff9a0804a5&gt;] irq_exit+0xb5/0xc0
[   47.938117]
[   47.938117] other info that might help us debug this:
[   47.938117]  Possible unsafe locking scenario:
[   47.938117]
[   47.938117]        CPU0
[   47.938117]        ----
[   47.938117]   lock(&amp;(&amp;ht-&gt;lock)-&gt;rlock);
[   47.938117]   &lt;Interrupt&gt;
[   47.938117]     lock(&amp;(&amp;ht-&gt;lock)-&gt;rlock);
[   47.938117]
[   47.938117]  *** DEADLOCK ***
[   47.938117]
[   47.938117] 2 locks held by swapper/3/0:
[   47.938117]  #0: 0000000062c64f90 ((&amp;d-&gt;timer)){+.-.}, at: call_timer_fn+0x5/0x280
[   47.938117]  #1: 00000000ee39619c (&amp;(&amp;d-&gt;lock)-&gt;rlock){+.-.}, at: tipc_disc_timeout+0xc8/0x540 [tipc]
[   47.938117]
[   47.938117] stack backtrace:
[   47.938117] CPU: 3 PID: 0 Comm: swapper/3 Tainted: G            E     4.19.0+ #37
[   47.938117] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[   47.938117] Call Trace:
[   47.938117]  &lt;IRQ&gt;
[   47.938117]  dump_stack+0x5e/0x8b
[   47.938117]  print_usage_bug+0x1ed/0x1ff
[   47.938117]  mark_lock+0x5b5/0x630
[   47.938117]  __lock_acquire+0x4c0/0x18f0
[   47.938117]  ? lock_acquire+0xa6/0x180
[   47.938117]  lock_acquire+0xa6/0x180
[   47.938117]  ? rhashtable_walk_enter+0x36/0xb0
[   47.938117]  _raw_spin_lock+0x29/0x60
[   47.938117]  ? rhashtable_walk_enter+0x36/0xb0
[   47.938117]  rhashtable_walk_enter+0x36/0xb0
[   47.938117]  tipc_sk_reinit+0xb0/0x410 [tipc]
[   47.938117]  ? mark_held_locks+0x6f/0x90
[   47.938117]  ? __local_bh_enable_ip+0x7a/0xf0
[   47.938117]  ? lockdep_hardirqs_on+0x20/0x1a0
[   47.938117]  tipc_net_finalize+0xbf/0x180 [tipc]
[   47.938117]  tipc_disc_timeout+0x509/0x540 [tipc]
[   47.938117]  ? call_timer_fn+0x5/0x280
[   47.938117]  ? tipc_disc_msg_xmit.isra.19+0xa0/0xa0 [tipc]
[   47.938117]  ? tipc_disc_msg_xmit.isra.19+0xa0/0xa0 [tipc]
[   47.938117]  call_timer_fn+0xa1/0x280
[   47.938117]  ? tipc_disc_msg_xmit.isra.19+0xa0/0xa0 [tipc]
[   47.938117]  run_timer_softirq+0x1f2/0x4d0
[   47.938117]  __do_softirq+0xfc/0x413
[   47.938117]  irq_exit+0xb5/0xc0
[   47.938117]  smp_apic_timer_interrupt+0xac/0x210
[   47.938117]  apic_timer_interrupt+0xf/0x20
[   47.938117]  &lt;/IRQ&gt;
[   47.938117] RIP: 0010:default_idle+0x1c/0x140
[   47.938117] Code: 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1f 44 00 00 41 54 55 53 65 8b 2d d8 2b 74 65 0f 1f 44 00 00 e8 c6 2c 8b ff fb f4 &lt;65&gt; 8b 2d c5 2b 74 65 0f 1f 44 00 00 5b 5d 41 5c c3 65 8b 05 b4 2b
[   47.938117] RSP: 0018:ffffaf6ac0207ec8 EFLAGS: 00000206 ORIG_RAX: ffffffffffffff13
[   47.938117] RAX: ffff8f5b3735e200 RBX: 0000000000000003 RCX: 0000000000000001
[   47.938117] RDX: 0000000000000001 RSI: 0000000000000001 RDI: ffff8f5b3735e200
[   47.938117] RBP: 0000000000000003 R08: 0000000000000001 R09: 0000000000000000
[   47.938117] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
[   47.938117] R13: 0000000000000000 R14: ffff8f5b3735e200 R15: ffff8f5b3735e200
[   47.938117]  ? default_idle+0x1a/0x140
[   47.938117]  do_idle+0x1bc/0x280
[   47.938117]  cpu_startup_entry+0x19/0x20
[   47.938117]  start_secondary+0x187/0x1c0
[   47.938117]  secondary_startup_64+0xa4/0xb0

The reason seems to be that tipc_net_finalize()-&gt;tipc_sk_reinit() is
calling the function rhashtable_walk_enter() within a timer interrupt.
We fix this by executing tipc_net_finalize() in work queue context.

Acked-by: Ying Xue &lt;ying.xue@windriver.com&gt;
Signed-off-by: Jon Maloy &lt;jon.maloy@ericsson.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>tipc: fix correct setting of message type in second discoverer</title>
<updated>2018-07-07T10:49:01+00:00</updated>
<author>
<name>Jon Maloy</name>
<email>jon.maloy@ericsson.com</email>
</author>
<published>2018-07-06T18:10:05+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=92018c7ca959ccd346d6235dac03cf7fc1ba51f7'/>
<id>92018c7ca959ccd346d6235dac03cf7fc1ba51f7</id>
<content type='text'>
The duplicate address discovery protocol is not safe against two
discoverers running in parallel. The one executing first after the
trial period is over will set the node address and change its own
message type to DSC_REQ_MSG. The one executing last may find that the
node address is already set, and never change message type, with the
result that its links may never be established.

In this commmit we ensure that the message type always is set correctly
after the trial period is over.

Fixes: 25b0b9c4e835 ("tipc: handle collisions of 32-bit node address hash values")
Signed-off-by: Jon Maloy &lt;jon.maloy@ericsson.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 duplicate address discovery protocol is not safe against two
discoverers running in parallel. The one executing first after the
trial period is over will set the node address and change its own
message type to DSC_REQ_MSG. The one executing last may find that the
node address is already set, and never change message type, with the
result that its links may never be established.

In this commmit we ensure that the message type always is set correctly
after the trial period is over.

Fixes: 25b0b9c4e835 ("tipc: handle collisions of 32-bit node address hash values")
Signed-off-by: Jon Maloy &lt;jon.maloy@ericsson.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>tipc: correct discovery message handling during address trial period</title>
<updated>2018-07-07T10:49:01+00:00</updated>
<author>
<name>Jon Maloy</name>
<email>jon.maloy@ericsson.com</email>
</author>
<published>2018-07-06T18:10:04+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=e415577f57f4452150642500364cbe5fa6112813'/>
<id>e415577f57f4452150642500364cbe5fa6112813</id>
<content type='text'>
With the duplicate address discovery protocol for tipc nodes addresses
we introduced a one second trial period before a node is allocated a
hash number to use as address.

Unfortunately, we miss to handle the case when a regular LINK REQUEST/
RESPONSE arrives from a cluster node during the trial period. Such
messages are not ignored as they should be, leading to links setup
attempts while the node still has no address.

Fixes: 25b0b9c4e835 ("tipc: handle collisions of 32-bit node address hash values")
Signed-off-by: Jon Maloy &lt;jon.maloy@ericsson.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>
With the duplicate address discovery protocol for tipc nodes addresses
we introduced a one second trial period before a node is allocated a
hash number to use as address.

Unfortunately, we miss to handle the case when a regular LINK REQUEST/
RESPONSE arrives from a cluster node during the trial period. Such
messages are not ignored as they should be, leading to links setup
attempts while the node still has no address.

Fixes: 25b0b9c4e835 ("tipc: handle collisions of 32-bit node address hash values")
Signed-off-by: Jon Maloy &lt;jon.maloy@ericsson.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>tipc: tipc_disc_addr_trial_msg() can be static</title>
<updated>2018-03-26T01:21:43+00:00</updated>
<author>
<name>kbuild test robot</name>
<email>fengguang.wu@intel.com</email>
</author>
<published>2018-03-23T19:47:42+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=da18ab32d78b6414267d3e5c8c9b5ab34a6d3321'/>
<id>da18ab32d78b6414267d3e5c8c9b5ab34a6d3321</id>
<content type='text'>
Fixes: 25b0b9c4e835 ("tipc: handle collisions of 32-bit node address hash values")
Signed-off-by: Fengguang Wu &lt;fengguang.wu@intel.com&gt;
Acked-by: Jon Maloy jon.maloy@ericsson.com
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Fixes: 25b0b9c4e835 ("tipc: handle collisions of 32-bit node address hash values")
Signed-off-by: Fengguang Wu &lt;fengguang.wu@intel.com&gt;
Acked-by: Jon Maloy jon.maloy@ericsson.com
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>tipc: handle collisions of 32-bit node address hash values</title>
<updated>2018-03-23T17:12:18+00:00</updated>
<author>
<name>Jon Maloy</name>
<email>jon.maloy@ericsson.com</email>
</author>
<published>2018-03-22T19:42:51+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=25b0b9c4e835ffaa65b61c3efe2e28acf84d0259'/>
<id>25b0b9c4e835ffaa65b61c3efe2e28acf84d0259</id>
<content type='text'>
When a 32-bit node address is generated from a 128-bit identifier,
there is a risk of collisions which must be discovered and handled.

We do this as follows:
- We don't apply the generated address immediately to the node, but do
  instead initiate a 1 sec trial period to allow other cluster members
  to discover and handle such collisions.

- During the trial period the node periodically sends out a new type
  of message, DSC_TRIAL_MSG, using broadcast or emulated broadcast,
  to all the other nodes in the cluster.

- When a node is receiving such a message, it must check that the
  presented 32-bit identifier either is unused, or was used by the very
  same peer in a previous session. In both cases it accepts the request
  by not responding to it.

- If it finds that the same node has been up before using a different
  address, it responds with a DSC_TRIAL_FAIL_MSG containing that
  address.

- If it finds that the address has already been taken by some other
  node, it generates a new, unused address and returns it to the
  requester.

- During the trial period the requesting node must always be prepared
  to accept a failure message, i.e., a message where a peer suggests a
  different (or equal)  address to the one tried. In those cases it
  must apply the suggested value as trial address and restart the trial
  period.

This algorithm ensures that in the vast majority of cases a node will
have the same address before and after a reboot. If a legacy user
configures the address explicitly, there will be no trial period and
messages, so this protocol addition is completely backwards compatible.

Acked-by: Ying Xue &lt;ying.xue@windriver.com&gt;
Signed-off-by: Jon Maloy &lt;jon.maloy@ericsson.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 32-bit node address is generated from a 128-bit identifier,
there is a risk of collisions which must be discovered and handled.

We do this as follows:
- We don't apply the generated address immediately to the node, but do
  instead initiate a 1 sec trial period to allow other cluster members
  to discover and handle such collisions.

- During the trial period the node periodically sends out a new type
  of message, DSC_TRIAL_MSG, using broadcast or emulated broadcast,
  to all the other nodes in the cluster.

- When a node is receiving such a message, it must check that the
  presented 32-bit identifier either is unused, or was used by the very
  same peer in a previous session. In both cases it accepts the request
  by not responding to it.

- If it finds that the same node has been up before using a different
  address, it responds with a DSC_TRIAL_FAIL_MSG containing that
  address.

- If it finds that the address has already been taken by some other
  node, it generates a new, unused address and returns it to the
  requester.

- During the trial period the requesting node must always be prepared
  to accept a failure message, i.e., a message where a peer suggests a
  different (or equal)  address to the one tried. In those cases it
  must apply the suggested value as trial address and restart the trial
  period.

This algorithm ensures that in the vast majority of cases a node will
have the same address before and after a reboot. If a legacy user
configures the address explicitly, there will be no trial period and
messages, so this protocol addition is completely backwards compatible.

Acked-by: Ying Xue &lt;ying.xue@windriver.com&gt;
Signed-off-by: Jon Maloy &lt;jon.maloy@ericsson.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
</feed>
