<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux.git/net/smc, branch v5.4.164</title>
<subtitle>Clone of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git</subtitle>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/'/>
<entry>
<title>net/smc: Keep smc_close_final rc during active close</title>
<updated>2021-12-08T08:01:13+00:00</updated>
<author>
<name>Tony Lu</name>
<email>tonylu@linux.alibaba.com</email>
</author>
<published>2021-12-01T06:42:16+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=10bad5a1977fb7fec17acc1d571885277c665e9f'/>
<id>10bad5a1977fb7fec17acc1d571885277c665e9f</id>
<content type='text'>
commit 00e158fb91dfaff3f94746f260d11f1a4853506e upstream.

When smc_close_final() returns error, the return code overwrites by
kernel_sock_shutdown() in smc_close_active(). The return code of
smc_close_final() is more important than kernel_sock_shutdown(), and it
will pass to userspace directly.

Fix it by keeping both return codes, if smc_close_final() raises an
error, return it or kernel_sock_shutdown()'s.

Link: https://lore.kernel.org/linux-s390/1f67548e-cbf6-0dce-82b5-10288a4583bd@linux.ibm.com/
Fixes: 606a63c9783a ("net/smc: Ensure the active closing peer first closes clcsock")
Suggested-by: Karsten Graul &lt;kgraul@linux.ibm.com&gt;
Signed-off-by: Tony Lu &lt;tonylu@linux.alibaba.com&gt;
Reviewed-by: Wen Gu &lt;guwen@linux.alibaba.com&gt;
Acked-by: Karsten Graul &lt;kgraul@linux.ibm.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>
commit 00e158fb91dfaff3f94746f260d11f1a4853506e upstream.

When smc_close_final() returns error, the return code overwrites by
kernel_sock_shutdown() in smc_close_active(). The return code of
smc_close_final() is more important than kernel_sock_shutdown(), and it
will pass to userspace directly.

Fix it by keeping both return codes, if smc_close_final() raises an
error, return it or kernel_sock_shutdown()'s.

Link: https://lore.kernel.org/linux-s390/1f67548e-cbf6-0dce-82b5-10288a4583bd@linux.ibm.com/
Fixes: 606a63c9783a ("net/smc: Ensure the active closing peer first closes clcsock")
Suggested-by: Karsten Graul &lt;kgraul@linux.ibm.com&gt;
Signed-off-by: Tony Lu &lt;tonylu@linux.alibaba.com&gt;
Reviewed-by: Wen Gu &lt;guwen@linux.alibaba.com&gt;
Acked-by: Karsten Graul &lt;kgraul@linux.ibm.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>net/smc: Avoid warning of possible recursive locking</title>
<updated>2021-12-08T08:01:10+00:00</updated>
<author>
<name>Wen Gu</name>
<email>guwen@linux.alibaba.com</email>
</author>
<published>2021-11-22T12:32:53+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=f82013d1d68f45f2563e6747b04971e33e709505'/>
<id>f82013d1d68f45f2563e6747b04971e33e709505</id>
<content type='text'>
[ Upstream commit 7a61432dc81375be06b02f0061247d3efbdfce3a ]

Possible recursive locking is detected by lockdep when SMC
falls back to TCP. The corresponding warnings are as follows:

 ============================================
 WARNING: possible recursive locking detected
 5.16.0-rc1+ #18 Tainted: G            E
 --------------------------------------------
 wrk/1391 is trying to acquire lock:
 ffff975246c8e7d8 (&amp;ei-&gt;socket.wq.wait){..-.}-{3:3}, at: smc_switch_to_fallback+0x109/0x250 [smc]

 but task is already holding lock:
 ffff975246c8f918 (&amp;ei-&gt;socket.wq.wait){..-.}-{3:3}, at: smc_switch_to_fallback+0xfe/0x250 [smc]

 other info that might help us debug this:
  Possible unsafe locking scenario:

        CPU0
        ----
   lock(&amp;ei-&gt;socket.wq.wait);
   lock(&amp;ei-&gt;socket.wq.wait);

  *** DEADLOCK ***

  May be due to missing lock nesting notation

 2 locks held by wrk/1391:
  #0: ffff975246040130 (sk_lock-AF_SMC){+.+.}-{0:0}, at: smc_connect+0x43/0x150 [smc]
  #1: ffff975246c8f918 (&amp;ei-&gt;socket.wq.wait){..-.}-{3:3}, at: smc_switch_to_fallback+0xfe/0x250 [smc]

 stack backtrace:
 Call Trace:
  &lt;TASK&gt;
  dump_stack_lvl+0x56/0x7b
  __lock_acquire+0x951/0x11f0
  lock_acquire+0x27a/0x320
  ? smc_switch_to_fallback+0x109/0x250 [smc]
  ? smc_switch_to_fallback+0xfe/0x250 [smc]
  _raw_spin_lock_irq+0x3b/0x80
  ? smc_switch_to_fallback+0x109/0x250 [smc]
  smc_switch_to_fallback+0x109/0x250 [smc]
  smc_connect_fallback+0xe/0x30 [smc]
  __smc_connect+0xcf/0x1090 [smc]
  ? mark_held_locks+0x61/0x80
  ? __local_bh_enable_ip+0x77/0xe0
  ? lockdep_hardirqs_on+0xbf/0x130
  ? smc_connect+0x12a/0x150 [smc]
  smc_connect+0x12a/0x150 [smc]
  __sys_connect+0x8a/0xc0
  ? syscall_enter_from_user_mode+0x20/0x70
  __x64_sys_connect+0x16/0x20
  do_syscall_64+0x34/0x90
  entry_SYSCALL_64_after_hwframe+0x44/0xae

The nested locking in smc_switch_to_fallback() is considered to
possibly cause a deadlock because smc_wait-&gt;lock and clc_wait-&gt;lock
are the same type of lock. But actually it is safe so far since
there is no other place trying to obtain smc_wait-&gt;lock when
clc_wait-&gt;lock is held. So the patch replaces spin_lock() with
spin_lock_nested() to avoid false report by lockdep.

Link: https://lkml.org/lkml/2021/11/19/962
Fixes: 2153bd1e3d3d ("Transfer remaining wait queue entries during fallback")
Reported-by: syzbot+e979d3597f48262cb4ee@syzkaller.appspotmail.com
Signed-off-by: Wen Gu &lt;guwen@linux.alibaba.com&gt;
Acked-by: Tony Lu &lt;tonylu@linux.alibaba.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 7a61432dc81375be06b02f0061247d3efbdfce3a ]

Possible recursive locking is detected by lockdep when SMC
falls back to TCP. The corresponding warnings are as follows:

 ============================================
 WARNING: possible recursive locking detected
 5.16.0-rc1+ #18 Tainted: G            E
 --------------------------------------------
 wrk/1391 is trying to acquire lock:
 ffff975246c8e7d8 (&amp;ei-&gt;socket.wq.wait){..-.}-{3:3}, at: smc_switch_to_fallback+0x109/0x250 [smc]

 but task is already holding lock:
 ffff975246c8f918 (&amp;ei-&gt;socket.wq.wait){..-.}-{3:3}, at: smc_switch_to_fallback+0xfe/0x250 [smc]

 other info that might help us debug this:
  Possible unsafe locking scenario:

        CPU0
        ----
   lock(&amp;ei-&gt;socket.wq.wait);
   lock(&amp;ei-&gt;socket.wq.wait);

  *** DEADLOCK ***

  May be due to missing lock nesting notation

 2 locks held by wrk/1391:
  #0: ffff975246040130 (sk_lock-AF_SMC){+.+.}-{0:0}, at: smc_connect+0x43/0x150 [smc]
  #1: ffff975246c8f918 (&amp;ei-&gt;socket.wq.wait){..-.}-{3:3}, at: smc_switch_to_fallback+0xfe/0x250 [smc]

 stack backtrace:
 Call Trace:
  &lt;TASK&gt;
  dump_stack_lvl+0x56/0x7b
  __lock_acquire+0x951/0x11f0
  lock_acquire+0x27a/0x320
  ? smc_switch_to_fallback+0x109/0x250 [smc]
  ? smc_switch_to_fallback+0xfe/0x250 [smc]
  _raw_spin_lock_irq+0x3b/0x80
  ? smc_switch_to_fallback+0x109/0x250 [smc]
  smc_switch_to_fallback+0x109/0x250 [smc]
  smc_connect_fallback+0xe/0x30 [smc]
  __smc_connect+0xcf/0x1090 [smc]
  ? mark_held_locks+0x61/0x80
  ? __local_bh_enable_ip+0x77/0xe0
  ? lockdep_hardirqs_on+0xbf/0x130
  ? smc_connect+0x12a/0x150 [smc]
  smc_connect+0x12a/0x150 [smc]
  __sys_connect+0x8a/0xc0
  ? syscall_enter_from_user_mode+0x20/0x70
  __x64_sys_connect+0x16/0x20
  do_syscall_64+0x34/0x90
  entry_SYSCALL_64_after_hwframe+0x44/0xae

The nested locking in smc_switch_to_fallback() is considered to
possibly cause a deadlock because smc_wait-&gt;lock and clc_wait-&gt;lock
are the same type of lock. But actually it is safe so far since
there is no other place trying to obtain smc_wait-&gt;lock when
clc_wait-&gt;lock is held. So the patch replaces spin_lock() with
spin_lock_nested() to avoid false report by lockdep.

Link: https://lkml.org/lkml/2021/11/19/962
Fixes: 2153bd1e3d3d ("Transfer remaining wait queue entries during fallback")
Reported-by: syzbot+e979d3597f48262cb4ee@syzkaller.appspotmail.com
Signed-off-by: Wen Gu &lt;guwen@linux.alibaba.com&gt;
Acked-by: Tony Lu &lt;tonylu@linux.alibaba.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>net/smc: Transfer remaining wait queue entries during fallback</title>
<updated>2021-12-08T08:01:09+00:00</updated>
<author>
<name>Wen Gu</name>
<email>guwen@linux.alibaba.com</email>
</author>
<published>2021-11-13T07:33:35+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=d6e981ec9491be5ec46d838b1151e7edefe607f5'/>
<id>d6e981ec9491be5ec46d838b1151e7edefe607f5</id>
<content type='text'>
[ Upstream commit 2153bd1e3d3dbf6a3403572084ef6ed31c53c5f0 ]

The SMC fallback is incomplete currently. There may be some
wait queue entries remaining in smc socket-&gt;wq, which should
be removed to clcsocket-&gt;wq during the fallback.

For example, in nginx/wrk benchmark, this issue causes an
all-zeros test result:

server: nginx -g 'daemon off;'
client: smc_run wrk -c 1 -t 1 -d 5 http://11.200.15.93/index.html

  Running 5s test @ http://11.200.15.93/index.html
     1 threads and 1 connections
     Thread Stats   Avg      Stdev     Max   ± Stdev
     	Latency     0.00us    0.00us   0.00us    -nan%
	Req/Sec     0.00      0.00     0.00      -nan%
	0 requests in 5.00s, 0.00B read
     Requests/sec:      0.00
     Transfer/sec:       0.00B

The reason for this all-zeros result is that when wrk used SMC
to replace TCP, it added an eppoll_entry into smc socket-&gt;wq
and expected to be notified if epoll events like EPOLL_IN/
EPOLL_OUT occurred on the smc socket.

However, once a fallback occurred, wrk switches to use clcsocket.
Now it is clcsocket-&gt;wq instead of smc socket-&gt;wq which will
be woken up. The eppoll_entry remaining in smc socket-&gt;wq does
not work anymore and wrk stops the test.

This patch fixes this issue by removing remaining wait queue
entries from smc socket-&gt;wq to clcsocket-&gt;wq during the fallback.

Link: https://www.spinics.net/lists/netdev/msg779769.html
Signed-off-by: Wen Gu &lt;guwen@linux.alibaba.com&gt;
Reviewed-by: Tony Lu &lt;tonylu@linux.alibaba.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 2153bd1e3d3dbf6a3403572084ef6ed31c53c5f0 ]

The SMC fallback is incomplete currently. There may be some
wait queue entries remaining in smc socket-&gt;wq, which should
be removed to clcsocket-&gt;wq during the fallback.

For example, in nginx/wrk benchmark, this issue causes an
all-zeros test result:

server: nginx -g 'daemon off;'
client: smc_run wrk -c 1 -t 1 -d 5 http://11.200.15.93/index.html

  Running 5s test @ http://11.200.15.93/index.html
     1 threads and 1 connections
     Thread Stats   Avg      Stdev     Max   ± Stdev
     	Latency     0.00us    0.00us   0.00us    -nan%
	Req/Sec     0.00      0.00     0.00      -nan%
	0 requests in 5.00s, 0.00B read
     Requests/sec:      0.00
     Transfer/sec:       0.00B

The reason for this all-zeros result is that when wrk used SMC
to replace TCP, it added an eppoll_entry into smc socket-&gt;wq
and expected to be notified if epoll events like EPOLL_IN/
EPOLL_OUT occurred on the smc socket.

However, once a fallback occurred, wrk switches to use clcsocket.
Now it is clcsocket-&gt;wq instead of smc socket-&gt;wq which will
be woken up. The eppoll_entry remaining in smc socket-&gt;wq does
not work anymore and wrk stops the test.

This patch fixes this issue by removing remaining wait queue
entries from smc socket-&gt;wq to clcsocket-&gt;wq during the fallback.

Link: https://www.spinics.net/lists/netdev/msg779769.html
Signed-off-by: Wen Gu &lt;guwen@linux.alibaba.com&gt;
Reviewed-by: Tony Lu &lt;tonylu@linux.alibaba.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>net/smc: Don't call clcsock shutdown twice when smc shutdown</title>
<updated>2021-12-01T08:23:34+00:00</updated>
<author>
<name>Tony Lu</name>
<email>tonylu@linux.alibaba.com</email>
</author>
<published>2021-11-26T02:41:35+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=3b961640399b69394fec0f9a94dd35bdada6a213'/>
<id>3b961640399b69394fec0f9a94dd35bdada6a213</id>
<content type='text'>
[ Upstream commit bacb6c1e47691cda4a95056c21b5487fb7199fcc ]

When applications call shutdown() with SHUT_RDWR in userspace,
smc_close_active() calls kernel_sock_shutdown(), and it is called
twice in smc_shutdown().

This fixes this by checking sk_state before do clcsock shutdown, and
avoids missing the application's call of smc_shutdown().

Link: https://lore.kernel.org/linux-s390/1f67548e-cbf6-0dce-82b5-10288a4583bd@linux.ibm.com/
Fixes: 606a63c9783a ("net/smc: Ensure the active closing peer first closes clcsock")
Signed-off-by: Tony Lu &lt;tonylu@linux.alibaba.com&gt;
Reviewed-by: Wen Gu &lt;guwen@linux.alibaba.com&gt;
Acked-by: Karsten Graul &lt;kgraul@linux.ibm.com&gt;
Link: https://lore.kernel.org/r/20211126024134.45693-1-tonylu@linux.alibaba.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 bacb6c1e47691cda4a95056c21b5487fb7199fcc ]

When applications call shutdown() with SHUT_RDWR in userspace,
smc_close_active() calls kernel_sock_shutdown(), and it is called
twice in smc_shutdown().

This fixes this by checking sk_state before do clcsock shutdown, and
avoids missing the application's call of smc_shutdown().

Link: https://lore.kernel.org/linux-s390/1f67548e-cbf6-0dce-82b5-10288a4583bd@linux.ibm.com/
Fixes: 606a63c9783a ("net/smc: Ensure the active closing peer first closes clcsock")
Signed-off-by: Tony Lu &lt;tonylu@linux.alibaba.com&gt;
Reviewed-by: Wen Gu &lt;guwen@linux.alibaba.com&gt;
Acked-by: Karsten Graul &lt;kgraul@linux.ibm.com&gt;
Link: https://lore.kernel.org/r/20211126024134.45693-1-tonylu@linux.alibaba.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>net/smc: Ensure the active closing peer first closes clcsock</title>
<updated>2021-12-01T08:23:33+00:00</updated>
<author>
<name>Tony Lu</name>
<email>tonylu@linux.alibaba.com</email>
</author>
<published>2021-11-23T08:25:18+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=6c0ab2caa8d1b08817e9d23b036688cf2d1981fe'/>
<id>6c0ab2caa8d1b08817e9d23b036688cf2d1981fe</id>
<content type='text'>
[ Upstream commit 606a63c9783a32a45bd2ef0eee393711d75b3284 ]

The side that actively closed socket, it's clcsock doesn't enter
TIME_WAIT state, but the passive side does it. It should show the same
behavior as TCP sockets.

Consider this, when client actively closes the socket, the clcsock in
server enters TIME_WAIT state, which means the address is occupied and
won't be reused before TIME_WAIT dismissing. If we restarted server, the
service would be unavailable for a long time.

To solve this issue, shutdown the clcsock in [A], perform the TCP active
close progress first, before the passive closed side closing it. So that
the actively closed side enters TIME_WAIT, not the passive one.

Client                                            |  Server
close() // client actively close                  |
  smc_release()                                   |
      smc_close_active() // PEERCLOSEWAIT1        |
          smc_close_final() // abort or closed = 1|
              smc_cdc_get_slot_and_msg_send()     |
          [A]                                     |
                                                  |smc_cdc_msg_recv_action() // ACTIVE
                                                  |  queue_work(smc_close_wq, &amp;conn-&gt;close_work)
                                                  |    smc_close_passive_work() // PROCESSABORT or APPCLOSEWAIT1
                                                  |      smc_close_passive_abort_received() // only in abort
                                                  |
                                                  |close() // server recv zero, close
                                                  |  smc_release() // PROCESSABORT or APPCLOSEWAIT1
                                                  |    smc_close_active()
                                                  |      smc_close_abort() or smc_close_final() // CLOSED
                                                  |        smc_cdc_get_slot_and_msg_send() // abort or closed = 1
smc_cdc_msg_recv_action()                         |    smc_clcsock_release()
  queue_work(smc_close_wq, &amp;conn-&gt;close_work)     |      sock_release(tcp) // actively close clc, enter TIME_WAIT
    smc_close_passive_work() // PEERCLOSEWAIT1    |    smc_conn_free()
      smc_close_passive_abort_received() // CLOSED|
      smc_conn_free()                             |
      smc_clcsock_release()                       |
        sock_release(tcp) // passive close clc    |

Link: https://www.spinics.net/lists/netdev/msg780407.html
Fixes: b38d732477e4 ("smc: socket closing and linkgroup cleanup")
Signed-off-by: Tony Lu &lt;tonylu@linux.alibaba.com&gt;
Reviewed-by: Wen Gu &lt;guwen@linux.alibaba.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 606a63c9783a32a45bd2ef0eee393711d75b3284 ]

The side that actively closed socket, it's clcsock doesn't enter
TIME_WAIT state, but the passive side does it. It should show the same
behavior as TCP sockets.

Consider this, when client actively closes the socket, the clcsock in
server enters TIME_WAIT state, which means the address is occupied and
won't be reused before TIME_WAIT dismissing. If we restarted server, the
service would be unavailable for a long time.

To solve this issue, shutdown the clcsock in [A], perform the TCP active
close progress first, before the passive closed side closing it. So that
the actively closed side enters TIME_WAIT, not the passive one.

Client                                            |  Server
close() // client actively close                  |
  smc_release()                                   |
      smc_close_active() // PEERCLOSEWAIT1        |
          smc_close_final() // abort or closed = 1|
              smc_cdc_get_slot_and_msg_send()     |
          [A]                                     |
                                                  |smc_cdc_msg_recv_action() // ACTIVE
                                                  |  queue_work(smc_close_wq, &amp;conn-&gt;close_work)
                                                  |    smc_close_passive_work() // PROCESSABORT or APPCLOSEWAIT1
                                                  |      smc_close_passive_abort_received() // only in abort
                                                  |
                                                  |close() // server recv zero, close
                                                  |  smc_release() // PROCESSABORT or APPCLOSEWAIT1
                                                  |    smc_close_active()
                                                  |      smc_close_abort() or smc_close_final() // CLOSED
                                                  |        smc_cdc_get_slot_and_msg_send() // abort or closed = 1
smc_cdc_msg_recv_action()                         |    smc_clcsock_release()
  queue_work(smc_close_wq, &amp;conn-&gt;close_work)     |      sock_release(tcp) // actively close clc, enter TIME_WAIT
    smc_close_passive_work() // PEERCLOSEWAIT1    |    smc_conn_free()
      smc_close_passive_abort_received() // CLOSED|
      smc_conn_free()                             |
      smc_clcsock_release()                       |
        sock_release(tcp) // passive close clc    |

Link: https://www.spinics.net/lists/netdev/msg780407.html
Fixes: b38d732477e4 ("smc: socket closing and linkgroup cleanup")
Signed-off-by: Tony Lu &lt;tonylu@linux.alibaba.com&gt;
Reviewed-by: Wen Gu &lt;guwen@linux.alibaba.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>net/smc: fix sk_refcnt underflow on linkdown and fallback</title>
<updated>2021-11-17T08:48:48+00:00</updated>
<author>
<name>Dust Li</name>
<email>dust.li@linux.alibaba.com</email>
</author>
<published>2021-11-10T07:02:34+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=1800c9eecd5e20dcbdca08f8676324645712b754'/>
<id>1800c9eecd5e20dcbdca08f8676324645712b754</id>
<content type='text'>
[ Upstream commit e5d5aadcf3cd59949316df49c27cb21788d7efe4 ]

We got the following WARNING when running ab/nginx
test with RDMA link flapping (up-down-up).
The reason is when smc_sock fallback and at linkdown
happens simultaneously, we may got the following situation:

__smc_lgr_terminate()
 --&gt; smc_conn_kill()
    --&gt; smc_close_active_abort()
           smc_sock-&gt;sk_state = SMC_CLOSED
           sock_put(smc_sock)

smc_sock was set to SMC_CLOSED and sock_put() been called
when terminate the link group. But later application call
close() on the socket, then we got:

__smc_release():
    if (smc_sock-&gt;fallback)
        smc_sock-&gt;sk_state = SMC_CLOSED
        sock_put(smc_sock)

Again we set the smc_sock to CLOSED through it's already
in CLOSED state, and double put the refcnt, so the following
warning happens:

refcount_t: underflow; use-after-free.
WARNING: CPU: 5 PID: 860 at lib/refcount.c:28 refcount_warn_saturate+0x8d/0xf0
Modules linked in:
CPU: 5 PID: 860 Comm: nginx Not tainted 5.10.46+ #403
Hardware name: Alibaba Cloud Alibaba Cloud ECS, BIOS 8c24b4c 04/01/2014
RIP: 0010:refcount_warn_saturate+0x8d/0xf0
Code: 05 5c 1e b5 01 01 e8 52 25 bc ff 0f 0b c3 80 3d 4f 1e b5 01 00 75 ad 48

RSP: 0018:ffffc90000527e50 EFLAGS: 00010286
RAX: 0000000000000026 RBX: ffff8881300df2c0 RCX: 0000000000000027
RDX: 0000000000000000 RSI: ffff88813bd58040 RDI: ffff88813bd58048
RBP: 0000000000000000 R08: 0000000000000003 R09: 0000000000000001
R10: ffff8881300df2c0 R11: ffffc90000527c78 R12: ffff8881300df340
R13: ffff8881300df930 R14: ffff88810b3dad80 R15: ffff8881300df4f8
FS:  00007f739de8fb80(0000) GS:ffff88813bd40000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000000a01b008 CR3: 0000000111b64003 CR4: 00000000003706e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 smc_release+0x353/0x3f0
 __sock_release+0x3d/0xb0
 sock_close+0x11/0x20
 __fput+0x93/0x230
 task_work_run+0x65/0xa0
 exit_to_user_mode_prepare+0xf9/0x100
 syscall_exit_to_user_mode+0x27/0x190
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

This patch adds check in __smc_release() to make
sure we won't do an extra sock_put() and set the
socket to CLOSED when its already in CLOSED state.

Fixes: 51f1de79ad8e (net/smc: replace sock_put worker by socket refcounting)
Signed-off-by: Dust Li &lt;dust.li@linux.alibaba.com&gt;
Reviewed-by: Tony Lu &lt;tonylu@linux.alibaba.com&gt;
Signed-off-by: Dust Li &lt;dust.li@linux.alibaba.com&gt;
Acked-by: Karsten Graul &lt;kgraul@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 e5d5aadcf3cd59949316df49c27cb21788d7efe4 ]

We got the following WARNING when running ab/nginx
test with RDMA link flapping (up-down-up).
The reason is when smc_sock fallback and at linkdown
happens simultaneously, we may got the following situation:

__smc_lgr_terminate()
 --&gt; smc_conn_kill()
    --&gt; smc_close_active_abort()
           smc_sock-&gt;sk_state = SMC_CLOSED
           sock_put(smc_sock)

smc_sock was set to SMC_CLOSED and sock_put() been called
when terminate the link group. But later application call
close() on the socket, then we got:

__smc_release():
    if (smc_sock-&gt;fallback)
        smc_sock-&gt;sk_state = SMC_CLOSED
        sock_put(smc_sock)

Again we set the smc_sock to CLOSED through it's already
in CLOSED state, and double put the refcnt, so the following
warning happens:

refcount_t: underflow; use-after-free.
WARNING: CPU: 5 PID: 860 at lib/refcount.c:28 refcount_warn_saturate+0x8d/0xf0
Modules linked in:
CPU: 5 PID: 860 Comm: nginx Not tainted 5.10.46+ #403
Hardware name: Alibaba Cloud Alibaba Cloud ECS, BIOS 8c24b4c 04/01/2014
RIP: 0010:refcount_warn_saturate+0x8d/0xf0
Code: 05 5c 1e b5 01 01 e8 52 25 bc ff 0f 0b c3 80 3d 4f 1e b5 01 00 75 ad 48

RSP: 0018:ffffc90000527e50 EFLAGS: 00010286
RAX: 0000000000000026 RBX: ffff8881300df2c0 RCX: 0000000000000027
RDX: 0000000000000000 RSI: ffff88813bd58040 RDI: ffff88813bd58048
RBP: 0000000000000000 R08: 0000000000000003 R09: 0000000000000001
R10: ffff8881300df2c0 R11: ffffc90000527c78 R12: ffff8881300df340
R13: ffff8881300df930 R14: ffff88810b3dad80 R15: ffff8881300df4f8
FS:  00007f739de8fb80(0000) GS:ffff88813bd40000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000000a01b008 CR3: 0000000111b64003 CR4: 00000000003706e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 smc_release+0x353/0x3f0
 __sock_release+0x3d/0xb0
 sock_close+0x11/0x20
 __fput+0x93/0x230
 task_work_run+0x65/0xa0
 exit_to_user_mode_prepare+0xf9/0x100
 syscall_exit_to_user_mode+0x27/0x190
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

This patch adds check in __smc_release() to make
sure we won't do an extra sock_put() and set the
socket to CLOSED when its already in CLOSED state.

Fixes: 51f1de79ad8e (net/smc: replace sock_put worker by socket refcounting)
Signed-off-by: Dust Li &lt;dust.li@linux.alibaba.com&gt;
Reviewed-by: Tony Lu &lt;tonylu@linux.alibaba.com&gt;
Signed-off-by: Dust Li &lt;dust.li@linux.alibaba.com&gt;
Acked-by: Karsten Graul &lt;kgraul@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>net/smc: Correct spelling mistake to TCPF_SYN_RECV</title>
<updated>2021-11-17T08:48:22+00:00</updated>
<author>
<name>Wen Gu</name>
<email>guwen@linux.alibaba.com</email>
</author>
<published>2021-10-28T07:13:47+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=87a87c82f7f316b8958ec08e6fec3bbad5669197'/>
<id>87a87c82f7f316b8958ec08e6fec3bbad5669197</id>
<content type='text'>
[ Upstream commit f3a3a0fe0b644582fa5d83dd94b398f99fc57914 ]

There should use TCPF_SYN_RECV instead of TCP_SYN_RECV.

Signed-off-by: Wen Gu &lt;guwen@linux.alibaba.com&gt;
Reviewed-by: Tony Lu &lt;tonylu@linux.alibaba.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 f3a3a0fe0b644582fa5d83dd94b398f99fc57914 ]

There should use TCPF_SYN_RECV instead of TCP_SYN_RECV.

Signed-off-by: Wen Gu &lt;guwen@linux.alibaba.com&gt;
Reviewed-by: Tony Lu &lt;tonylu@linux.alibaba.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>net/smc: add missing error check in smc_clc_prfx_set()</title>
<updated>2021-09-30T08:09:23+00:00</updated>
<author>
<name>Karsten Graul</name>
<email>kgraul@linux.ibm.com</email>
</author>
<published>2021-09-20T19:18:14+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=f7fb7dbdfb25091f38833bf76d330075e15fb31e'/>
<id>f7fb7dbdfb25091f38833bf76d330075e15fb31e</id>
<content type='text'>
[ Upstream commit 6c90731980655280ea07ce4b21eb97457bf86286 ]

Coverity stumbled over a missing error check in smc_clc_prfx_set():

*** CID 1475954:  Error handling issues  (CHECKED_RETURN)
/net/smc/smc_clc.c: 233 in smc_clc_prfx_set()
&gt;&gt;&gt;     CID 1475954:  Error handling issues  (CHECKED_RETURN)
&gt;&gt;&gt;     Calling "kernel_getsockname" without checking return value (as is done elsewhere 8 out of 10 times).
233     	kernel_getsockname(clcsock, (struct sockaddr *)&amp;addrs);

Add the return code check in smc_clc_prfx_set().

Fixes: c246d942eabc ("net/smc: restructure netinfo for CLC proposal msgs")
Reported-by: Julian Wiedmann &lt;jwi@linux.ibm.com&gt;
Signed-off-by: Karsten Graul &lt;kgraul@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 6c90731980655280ea07ce4b21eb97457bf86286 ]

Coverity stumbled over a missing error check in smc_clc_prfx_set():

*** CID 1475954:  Error handling issues  (CHECKED_RETURN)
/net/smc/smc_clc.c: 233 in smc_clc_prfx_set()
&gt;&gt;&gt;     CID 1475954:  Error handling issues  (CHECKED_RETURN)
&gt;&gt;&gt;     Calling "kernel_getsockname" without checking return value (as is done elsewhere 8 out of 10 times).
233     	kernel_getsockname(clcsock, (struct sockaddr *)&amp;addrs);

Add the return code check in smc_clc_prfx_set().

Fixes: c246d942eabc ("net/smc: restructure netinfo for CLC proposal msgs")
Reported-by: Julian Wiedmann &lt;jwi@linux.ibm.com&gt;
Signed-off-by: Karsten Graul &lt;kgraul@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>Revert "net/smc: fix a NULL pointer dereference"</title>
<updated>2021-06-03T06:59:08+00:00</updated>
<author>
<name>Greg Kroah-Hartman</name>
<email>gregkh@linuxfoundation.org</email>
</author>
<published>2021-05-03T11:56:43+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=e8dee217eca8d644d86817b0a9403b8c824ce488'/>
<id>e8dee217eca8d644d86817b0a9403b8c824ce488</id>
<content type='text'>
[ Upstream commit 5369ead83f5aff223b6418c99cb1fe9a8f007363 ]

This reverts commit e183d4e414b64711baf7a04e214b61969ca08dfa.

Because of recent interactions with developers from @umn.edu, all
commits from them have been recently re-reviewed to ensure if they were
correct or not.

Upon review, this commit was found to be incorrect for the reasons
below, so it must be reverted.  It will be fixed up "correctly" in a
later kernel change.

The original commit causes a memory leak and does not properly fix the
issue it claims to fix.  I will send a follow-on patch to resolve this
properly.

Cc: Kangjie Lu &lt;kjlu@umn.edu&gt;
Cc: Ursula Braun &lt;ubraun@linux.ibm.com&gt;
Cc: David S. Miller &lt;davem@davemloft.net&gt;
Link: https://lore.kernel.org/r/20210503115736.2104747-17-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.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 5369ead83f5aff223b6418c99cb1fe9a8f007363 ]

This reverts commit e183d4e414b64711baf7a04e214b61969ca08dfa.

Because of recent interactions with developers from @umn.edu, all
commits from them have been recently re-reviewed to ensure if they were
correct or not.

Upon review, this commit was found to be incorrect for the reasons
below, so it must be reverted.  It will be fixed up "correctly" in a
later kernel change.

The original commit causes a memory leak and does not properly fix the
issue it claims to fix.  I will send a follow-on patch to resolve this
properly.

Cc: Kangjie Lu &lt;kjlu@umn.edu&gt;
Cc: Ursula Braun &lt;ubraun@linux.ibm.com&gt;
Cc: David S. Miller &lt;davem@davemloft.net&gt;
Link: https://lore.kernel.org/r/20210503115736.2104747-17-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>smc: disallow TCP_ULP in smc_setsockopt()</title>
<updated>2021-05-19T08:08:28+00:00</updated>
<author>
<name>Cong Wang</name>
<email>cong.wang@bytedance.com</email>
</author>
<published>2021-05-05T19:40:48+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=ca74d0dbaffa78f73d0f0238d63c64494452195b'/>
<id>ca74d0dbaffa78f73d0f0238d63c64494452195b</id>
<content type='text'>
[ Upstream commit 8621436671f3a4bba5db57482e1ee604708bf1eb ]

syzbot is able to setup kTLS on an SMC socket which coincidentally
uses sk_user_data too. Later, kTLS treats it as psock so triggers a
refcnt warning. The root cause is that smc_setsockopt() simply calls
TCP setsockopt() which includes TCP_ULP. I do not think it makes
sense to setup kTLS on top of SMC sockets, so we should just disallow
this setup.

It is hard to find a commit to blame, but we can apply this patch
since the beginning of TCP_ULP.

Reported-and-tested-by: syzbot+b54a1ce86ba4a623b7f0@syzkaller.appspotmail.com
Fixes: 734942cc4ea6 ("tcp: ULP infrastructure")
Cc: John Fastabend &lt;john.fastabend@gmail.com&gt;
Signed-off-by: Karsten Graul &lt;kgraul@linux.ibm.com&gt;
Signed-off-by: Cong Wang &lt;cong.wang@bytedance.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 8621436671f3a4bba5db57482e1ee604708bf1eb ]

syzbot is able to setup kTLS on an SMC socket which coincidentally
uses sk_user_data too. Later, kTLS treats it as psock so triggers a
refcnt warning. The root cause is that smc_setsockopt() simply calls
TCP setsockopt() which includes TCP_ULP. I do not think it makes
sense to setup kTLS on top of SMC sockets, so we should just disallow
this setup.

It is hard to find a commit to blame, but we can apply this patch
since the beginning of TCP_ULP.

Reported-and-tested-by: syzbot+b54a1ce86ba4a623b7f0@syzkaller.appspotmail.com
Fixes: 734942cc4ea6 ("tcp: ULP infrastructure")
Cc: John Fastabend &lt;john.fastabend@gmail.com&gt;
Signed-off-by: Karsten Graul &lt;kgraul@linux.ibm.com&gt;
Signed-off-by: Cong Wang &lt;cong.wang@bytedance.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>
</feed>
