<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/net/tipc/socket.c, branch v5.4.26</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>tipc: fix wrong timeout input for tipc_wait_for_cond()</title>
<updated>2020-01-26T09:01:00+00:00</updated>
<author>
<name>Tung Nguyen</name>
<email>tung.q.nguyen@dektech.com.au</email>
</author>
<published>2019-11-28T03:10:07+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=9bc7663b711a6f3c46f35f6b7e1d53449f451b2f'/>
<id>9bc7663b711a6f3c46f35f6b7e1d53449f451b2f</id>
<content type='text'>
commit 12db3c8083fcab4270866a88191933f2d9f24f89 upstream.

In function __tipc_shutdown(), the timeout value passed to
tipc_wait_for_cond() is not jiffies.

This commit fixes it by converting that value from milliseconds
to jiffies.

Fixes: 365ad353c256 ("tipc: reduce risk of user starvation during link congestion")
Signed-off-by: Tung Nguyen &lt;tung.q.nguyen@dektech.com.au&gt;
Acked-by: Jon Maloy &lt;jon.maloy@ericsson.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 12db3c8083fcab4270866a88191933f2d9f24f89 upstream.

In function __tipc_shutdown(), the timeout value passed to
tipc_wait_for_cond() is not jiffies.

This commit fixes it by converting that value from milliseconds
to jiffies.

Fixes: 365ad353c256 ("tipc: reduce risk of user starvation during link congestion")
Signed-off-by: Tung Nguyen &lt;tung.q.nguyen@dektech.com.au&gt;
Acked-by: Jon Maloy &lt;jon.maloy@ericsson.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>tipc: fix wrong socket reference counter after tipc_sk_timeout() returns</title>
<updated>2020-01-26T09:01:00+00:00</updated>
<author>
<name>Tung Nguyen</name>
<email>tung.q.nguyen@dektech.com.au</email>
</author>
<published>2019-11-28T03:10:06+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=58e007884a7bf7ad34552f266e7bb51cc9a7273b'/>
<id>58e007884a7bf7ad34552f266e7bb51cc9a7273b</id>
<content type='text'>
commit 91a4a3eb433e4d786420c41f3c08d1d16c605962 upstream.

When tipc_sk_timeout() is executed but user space is grabbing
ownership, this function rearms itself and returns. However, the
socket reference counter is not reduced. This causes potential
unexpected behavior.

This commit fixes it by calling sock_put() before tipc_sk_timeout()
returns in the above-mentioned case.

Fixes: afe8792fec69 ("tipc: refactor function tipc_sk_timeout()")
Signed-off-by: Tung Nguyen &lt;tung.q.nguyen@dektech.com.au&gt;
Acked-by: Ying Xue &lt;ying.xue@windriver.com&gt;
Acked-by: Jon Maloy &lt;jon.maloy@ericsson.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 91a4a3eb433e4d786420c41f3c08d1d16c605962 upstream.

When tipc_sk_timeout() is executed but user space is grabbing
ownership, this function rearms itself and returns. However, the
socket reference counter is not reduced. This causes potential
unexpected behavior.

This commit fixes it by calling sock_put() before tipc_sk_timeout()
returns in the above-mentioned case.

Fixes: afe8792fec69 ("tipc: refactor function tipc_sk_timeout()")
Signed-off-by: Tung Nguyen &lt;tung.q.nguyen@dektech.com.au&gt;
Acked-by: Ying Xue &lt;ying.xue@windriver.com&gt;
Acked-by: Jon Maloy &lt;jon.maloy@ericsson.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>tipc: fix potential memory leak in __tipc_sendmsg()</title>
<updated>2020-01-26T09:01:00+00:00</updated>
<author>
<name>Tung Nguyen</name>
<email>tung.q.nguyen@dektech.com.au</email>
</author>
<published>2019-11-28T03:10:05+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=55a0b2c95fd47db2adfeae50840c4b3a87c56179'/>
<id>55a0b2c95fd47db2adfeae50840c4b3a87c56179</id>
<content type='text'>
commit 2fe97a578d7bad3116a89dc8a6692a51e6fc1d9c upstream.

When initiating a connection message to a server side, the connection
message is cloned and added to the socket write queue. However, if the
cloning is failed, only the socket write queue is purged. It causes
memory leak because the original connection message is not freed.

This commit fixes it by purging the list of connection message when
it cannot be cloned.

Fixes: 6787927475e5 ("tipc: buffer overflow handling in listener socket")
Reported-by: Hoang Le &lt;hoang.h.le@dektech.com.au&gt;
Signed-off-by: Tung Nguyen &lt;tung.q.nguyen@dektech.com.au&gt;
Acked-by: Ying Xue &lt;ying.xue@windriver.com&gt;
Acked-by: Jon Maloy &lt;jon.maloy@ericsson.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 2fe97a578d7bad3116a89dc8a6692a51e6fc1d9c upstream.

When initiating a connection message to a server side, the connection
message is cloned and added to the socket write queue. However, if the
cloning is failed, only the socket write queue is purged. It causes
memory leak because the original connection message is not freed.

This commit fixes it by purging the list of connection message when
it cannot be cloned.

Fixes: 6787927475e5 ("tipc: buffer overflow handling in listener socket")
Reported-by: Hoang Le &lt;hoang.h.le@dektech.com.au&gt;
Signed-off-by: Tung Nguyen &lt;tung.q.nguyen@dektech.com.au&gt;
Acked-by: Ying Xue &lt;ying.xue@windriver.com&gt;
Acked-by: Jon Maloy &lt;jon.maloy@ericsson.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>tipc: fix retrans failure due to wrong destination</title>
<updated>2020-01-23T07:22:44+00:00</updated>
<author>
<name>Tuong Lien</name>
<email>tuong.t.lien@dektech.com.au</email>
</author>
<published>2019-12-10T08:21:04+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=4e7c55aabfd567e60542f7a2d09419226653ff72'/>
<id>4e7c55aabfd567e60542f7a2d09419226653ff72</id>
<content type='text'>
commit abc9b4e0549b93fdaff56e9532bc49a2d7b04955 upstream.

When a user message is sent, TIPC will check if the socket has faced a
congestion at link layer. If that happens, it will make a sleep to wait
for the congestion to disappear. This leaves a gap for other users to
take over the socket (e.g. multi threads) since the socket is released
as well. Also, in case of connectionless (e.g. SOCK_RDM), user is free
to send messages to various destinations (e.g. via 'sendto()'), then
the socket's preformatted header has to be updated correspondingly
prior to the actual payload message building.

Unfortunately, the latter action is done before the first action which
causes a condition issue that the destination of a certain message can
be modified incorrectly in the middle, leading to wrong destination
when that message is built. Consequently, when the message is sent to
the link layer, it gets stuck there forever because the peer node will
simply reject it. After a number of retransmission attempts, the link
is eventually taken down and the retransmission failure is reported.

This commit fixes the problem by rearranging the order of actions to
prevent the race condition from occurring, so the message building is
'atomic' and its header will not be modified by anyone.

Fixes: 365ad353c256 ("tipc: reduce risk of user starvation during link congestion")
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 abc9b4e0549b93fdaff56e9532bc49a2d7b04955 upstream.

When a user message is sent, TIPC will check if the socket has faced a
congestion at link layer. If that happens, it will make a sleep to wait
for the congestion to disappear. This leaves a gap for other users to
take over the socket (e.g. multi threads) since the socket is released
as well. Also, in case of connectionless (e.g. SOCK_RDM), user is free
to send messages to various destinations (e.g. via 'sendto()'), then
the socket's preformatted header has to be updated correspondingly
prior to the actual payload message building.

Unfortunately, the latter action is done before the first action which
causes a condition issue that the destination of a certain message can
be modified incorrectly in the middle, leading to wrong destination
when that message is built. Consequently, when the message is sent to
the link layer, it gets stuck there forever because the peer node will
simply reject it. After a number of retransmission attempts, the link
is eventually taken down and the retransmission failure is reported.

This commit fixes the problem by rearranging the order of actions to
prevent the race condition from occurring, so the message building is
'atomic' and its header will not be modified by anyone.

Fixes: 365ad353c256 ("tipc: reduce risk of user starvation during link congestion")
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>net: use skb_queue_empty_lockless() in poll() handlers</title>
<updated>2019-10-28T20:33:41+00:00</updated>
<author>
<name>Eric Dumazet</name>
<email>edumazet@google.com</email>
</author>
<published>2019-10-24T05:44:50+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=3ef7cf57c72f32f61e97f8fa401bc39ea1f1a5d4'/>
<id>3ef7cf57c72f32f61e97f8fa401bc39ea1f1a5d4</id>
<content type='text'>
Many poll() handlers are lockless. Using skb_queue_empty_lockless()
instead of skb_queue_empty() is more appropriate.

Signed-off-by: Eric Dumazet &lt;edumazet@google.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Many poll() handlers are lockless. Using skb_queue_empty_lockless()
instead of skb_queue_empty() is more appropriate.

Signed-off-by: Eric Dumazet &lt;edumazet@google.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>net: silence KCSAN warnings about sk-&gt;sk_backlog.len reads</title>
<updated>2019-10-10T04:43:00+00:00</updated>
<author>
<name>Eric Dumazet</name>
<email>edumazet@google.com</email>
</author>
<published>2019-10-09T22:41:03+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=70c2655849a25431f31b505a07fe0c861e5e41fb'/>
<id>70c2655849a25431f31b505a07fe0c861e5e41fb</id>
<content type='text'>
sk-&gt;sk_backlog.len can be written by BH handlers, and read
from process contexts in a lockless way.

Note the write side should also use WRITE_ONCE() or a variant.
We need some agreement about the best way to do this.

syzbot reported :

BUG: KCSAN: data-race in tcp_add_backlog / tcp_grow_window.isra.0

write to 0xffff88812665f32c of 4 bytes by interrupt on cpu 1:
 sk_add_backlog include/net/sock.h:934 [inline]
 tcp_add_backlog+0x4a0/0xcc0 net/ipv4/tcp_ipv4.c:1737
 tcp_v4_rcv+0x1aba/0x1bf0 net/ipv4/tcp_ipv4.c:1925
 ip_protocol_deliver_rcu+0x51/0x470 net/ipv4/ip_input.c:204
 ip_local_deliver_finish+0x110/0x140 net/ipv4/ip_input.c:231
 NF_HOOK include/linux/netfilter.h:305 [inline]
 NF_HOOK include/linux/netfilter.h:299 [inline]
 ip_local_deliver+0x133/0x210 net/ipv4/ip_input.c:252
 dst_input include/net/dst.h:442 [inline]
 ip_rcv_finish+0x121/0x160 net/ipv4/ip_input.c:413
 NF_HOOK include/linux/netfilter.h:305 [inline]
 NF_HOOK include/linux/netfilter.h:299 [inline]
 ip_rcv+0x18f/0x1a0 net/ipv4/ip_input.c:523
 __netif_receive_skb_one_core+0xa7/0xe0 net/core/dev.c:5004
 __netif_receive_skb+0x37/0xf0 net/core/dev.c:5118
 netif_receive_skb_internal+0x59/0x190 net/core/dev.c:5208
 napi_skb_finish net/core/dev.c:5671 [inline]
 napi_gro_receive+0x28f/0x330 net/core/dev.c:5704
 receive_buf+0x284/0x30b0 drivers/net/virtio_net.c:1061
 virtnet_receive drivers/net/virtio_net.c:1323 [inline]
 virtnet_poll+0x436/0x7d0 drivers/net/virtio_net.c:1428
 napi_poll net/core/dev.c:6352 [inline]
 net_rx_action+0x3ae/0xa50 net/core/dev.c:6418

read to 0xffff88812665f32c of 4 bytes by task 7292 on cpu 0:
 tcp_space include/net/tcp.h:1373 [inline]
 tcp_grow_window.isra.0+0x6b/0x480 net/ipv4/tcp_input.c:413
 tcp_event_data_recv+0x68f/0x990 net/ipv4/tcp_input.c:717
 tcp_rcv_established+0xbfe/0xf50 net/ipv4/tcp_input.c:5618
 tcp_v4_do_rcv+0x381/0x4e0 net/ipv4/tcp_ipv4.c:1542
 sk_backlog_rcv include/net/sock.h:945 [inline]
 __release_sock+0x135/0x1e0 net/core/sock.c:2427
 release_sock+0x61/0x160 net/core/sock.c:2943
 tcp_recvmsg+0x63b/0x1a30 net/ipv4/tcp.c:2181
 inet_recvmsg+0xbb/0x250 net/ipv4/af_inet.c:838
 sock_recvmsg_nosec net/socket.c:871 [inline]
 sock_recvmsg net/socket.c:889 [inline]
 sock_recvmsg+0x92/0xb0 net/socket.c:885
 sock_read_iter+0x15f/0x1e0 net/socket.c:967
 call_read_iter include/linux/fs.h:1864 [inline]
 new_sync_read+0x389/0x4f0 fs/read_write.c:414
 __vfs_read+0xb1/0xc0 fs/read_write.c:427
 vfs_read fs/read_write.c:461 [inline]
 vfs_read+0x143/0x2c0 fs/read_write.c:446

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 7292 Comm: syz-fuzzer Not tainted 5.3.0+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011

Signed-off-by: Eric Dumazet &lt;edumazet@google.com&gt;
Reported-by: syzbot &lt;syzkaller@googlegroups.com&gt;
Signed-off-by: Jakub Kicinski &lt;jakub.kicinski@netronome.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
sk-&gt;sk_backlog.len can be written by BH handlers, and read
from process contexts in a lockless way.

Note the write side should also use WRITE_ONCE() or a variant.
We need some agreement about the best way to do this.

syzbot reported :

BUG: KCSAN: data-race in tcp_add_backlog / tcp_grow_window.isra.0

write to 0xffff88812665f32c of 4 bytes by interrupt on cpu 1:
 sk_add_backlog include/net/sock.h:934 [inline]
 tcp_add_backlog+0x4a0/0xcc0 net/ipv4/tcp_ipv4.c:1737
 tcp_v4_rcv+0x1aba/0x1bf0 net/ipv4/tcp_ipv4.c:1925
 ip_protocol_deliver_rcu+0x51/0x470 net/ipv4/ip_input.c:204
 ip_local_deliver_finish+0x110/0x140 net/ipv4/ip_input.c:231
 NF_HOOK include/linux/netfilter.h:305 [inline]
 NF_HOOK include/linux/netfilter.h:299 [inline]
 ip_local_deliver+0x133/0x210 net/ipv4/ip_input.c:252
 dst_input include/net/dst.h:442 [inline]
 ip_rcv_finish+0x121/0x160 net/ipv4/ip_input.c:413
 NF_HOOK include/linux/netfilter.h:305 [inline]
 NF_HOOK include/linux/netfilter.h:299 [inline]
 ip_rcv+0x18f/0x1a0 net/ipv4/ip_input.c:523
 __netif_receive_skb_one_core+0xa7/0xe0 net/core/dev.c:5004
 __netif_receive_skb+0x37/0xf0 net/core/dev.c:5118
 netif_receive_skb_internal+0x59/0x190 net/core/dev.c:5208
 napi_skb_finish net/core/dev.c:5671 [inline]
 napi_gro_receive+0x28f/0x330 net/core/dev.c:5704
 receive_buf+0x284/0x30b0 drivers/net/virtio_net.c:1061
 virtnet_receive drivers/net/virtio_net.c:1323 [inline]
 virtnet_poll+0x436/0x7d0 drivers/net/virtio_net.c:1428
 napi_poll net/core/dev.c:6352 [inline]
 net_rx_action+0x3ae/0xa50 net/core/dev.c:6418

read to 0xffff88812665f32c of 4 bytes by task 7292 on cpu 0:
 tcp_space include/net/tcp.h:1373 [inline]
 tcp_grow_window.isra.0+0x6b/0x480 net/ipv4/tcp_input.c:413
 tcp_event_data_recv+0x68f/0x990 net/ipv4/tcp_input.c:717
 tcp_rcv_established+0xbfe/0xf50 net/ipv4/tcp_input.c:5618
 tcp_v4_do_rcv+0x381/0x4e0 net/ipv4/tcp_ipv4.c:1542
 sk_backlog_rcv include/net/sock.h:945 [inline]
 __release_sock+0x135/0x1e0 net/core/sock.c:2427
 release_sock+0x61/0x160 net/core/sock.c:2943
 tcp_recvmsg+0x63b/0x1a30 net/ipv4/tcp.c:2181
 inet_recvmsg+0xbb/0x250 net/ipv4/af_inet.c:838
 sock_recvmsg_nosec net/socket.c:871 [inline]
 sock_recvmsg net/socket.c:889 [inline]
 sock_recvmsg+0x92/0xb0 net/socket.c:885
 sock_read_iter+0x15f/0x1e0 net/socket.c:967
 call_read_iter include/linux/fs.h:1864 [inline]
 new_sync_read+0x389/0x4f0 fs/read_write.c:414
 __vfs_read+0xb1/0xc0 fs/read_write.c:427
 vfs_read fs/read_write.c:461 [inline]
 vfs_read+0x143/0x2c0 fs/read_write.c:446

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 7292 Comm: syz-fuzzer Not tainted 5.3.0+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011

Signed-off-by: Eric Dumazet &lt;edumazet@google.com&gt;
Reported-by: syzbot &lt;syzkaller@googlegroups.com&gt;
Signed-off-by: Jakub Kicinski &lt;jakub.kicinski@netronome.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>net: silence KCSAN warnings around sk_add_backlog() calls</title>
<updated>2019-10-10T04:42:59+00:00</updated>
<author>
<name>Eric Dumazet</name>
<email>edumazet@google.com</email>
</author>
<published>2019-10-09T22:21:13+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=8265792bf8871acc2d00fd03883d830e2249d395'/>
<id>8265792bf8871acc2d00fd03883d830e2249d395</id>
<content type='text'>
sk_add_backlog() callers usually read sk-&gt;sk_rcvbuf without
owning the socket lock. This means sk_rcvbuf value can
be changed by other cpus, and KCSAN complains.

Add READ_ONCE() annotations to document the lockless nature
of these reads.

Note that writes over sk_rcvbuf should also use WRITE_ONCE(),
but this will be done in separate patches to ease stable
backports (if we decide this is relevant for stable trees).

BUG: KCSAN: data-race in tcp_add_backlog / tcp_recvmsg

write to 0xffff88812ab369f8 of 8 bytes by interrupt on cpu 1:
 __sk_add_backlog include/net/sock.h:902 [inline]
 sk_add_backlog include/net/sock.h:933 [inline]
 tcp_add_backlog+0x45a/0xcc0 net/ipv4/tcp_ipv4.c:1737
 tcp_v4_rcv+0x1aba/0x1bf0 net/ipv4/tcp_ipv4.c:1925
 ip_protocol_deliver_rcu+0x51/0x470 net/ipv4/ip_input.c:204
 ip_local_deliver_finish+0x110/0x140 net/ipv4/ip_input.c:231
 NF_HOOK include/linux/netfilter.h:305 [inline]
 NF_HOOK include/linux/netfilter.h:299 [inline]
 ip_local_deliver+0x133/0x210 net/ipv4/ip_input.c:252
 dst_input include/net/dst.h:442 [inline]
 ip_rcv_finish+0x121/0x160 net/ipv4/ip_input.c:413
 NF_HOOK include/linux/netfilter.h:305 [inline]
 NF_HOOK include/linux/netfilter.h:299 [inline]
 ip_rcv+0x18f/0x1a0 net/ipv4/ip_input.c:523
 __netif_receive_skb_one_core+0xa7/0xe0 net/core/dev.c:5004
 __netif_receive_skb+0x37/0xf0 net/core/dev.c:5118
 netif_receive_skb_internal+0x59/0x190 net/core/dev.c:5208
 napi_skb_finish net/core/dev.c:5671 [inline]
 napi_gro_receive+0x28f/0x330 net/core/dev.c:5704
 receive_buf+0x284/0x30b0 drivers/net/virtio_net.c:1061
 virtnet_receive drivers/net/virtio_net.c:1323 [inline]
 virtnet_poll+0x436/0x7d0 drivers/net/virtio_net.c:1428
 napi_poll net/core/dev.c:6352 [inline]
 net_rx_action+0x3ae/0xa50 net/core/dev.c:6418

read to 0xffff88812ab369f8 of 8 bytes by task 7271 on cpu 0:
 tcp_recvmsg+0x470/0x1a30 net/ipv4/tcp.c:2047
 inet_recvmsg+0xbb/0x250 net/ipv4/af_inet.c:838
 sock_recvmsg_nosec net/socket.c:871 [inline]
 sock_recvmsg net/socket.c:889 [inline]
 sock_recvmsg+0x92/0xb0 net/socket.c:885
 sock_read_iter+0x15f/0x1e0 net/socket.c:967
 call_read_iter include/linux/fs.h:1864 [inline]
 new_sync_read+0x389/0x4f0 fs/read_write.c:414
 __vfs_read+0xb1/0xc0 fs/read_write.c:427
 vfs_read fs/read_write.c:461 [inline]
 vfs_read+0x143/0x2c0 fs/read_write.c:446
 ksys_read+0xd5/0x1b0 fs/read_write.c:587
 __do_sys_read fs/read_write.c:597 [inline]
 __se_sys_read fs/read_write.c:595 [inline]
 __x64_sys_read+0x4c/0x60 fs/read_write.c:595
 do_syscall_64+0xcf/0x2f0 arch/x86/entry/common.c:296
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 7271 Comm: syz-fuzzer Not tainted 5.3.0+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011

Signed-off-by: Eric Dumazet &lt;edumazet@google.com&gt;
Reported-by: syzbot &lt;syzkaller@googlegroups.com&gt;
Signed-off-by: Jakub Kicinski &lt;jakub.kicinski@netronome.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
sk_add_backlog() callers usually read sk-&gt;sk_rcvbuf without
owning the socket lock. This means sk_rcvbuf value can
be changed by other cpus, and KCSAN complains.

Add READ_ONCE() annotations to document the lockless nature
of these reads.

Note that writes over sk_rcvbuf should also use WRITE_ONCE(),
but this will be done in separate patches to ease stable
backports (if we decide this is relevant for stable trees).

BUG: KCSAN: data-race in tcp_add_backlog / tcp_recvmsg

write to 0xffff88812ab369f8 of 8 bytes by interrupt on cpu 1:
 __sk_add_backlog include/net/sock.h:902 [inline]
 sk_add_backlog include/net/sock.h:933 [inline]
 tcp_add_backlog+0x45a/0xcc0 net/ipv4/tcp_ipv4.c:1737
 tcp_v4_rcv+0x1aba/0x1bf0 net/ipv4/tcp_ipv4.c:1925
 ip_protocol_deliver_rcu+0x51/0x470 net/ipv4/ip_input.c:204
 ip_local_deliver_finish+0x110/0x140 net/ipv4/ip_input.c:231
 NF_HOOK include/linux/netfilter.h:305 [inline]
 NF_HOOK include/linux/netfilter.h:299 [inline]
 ip_local_deliver+0x133/0x210 net/ipv4/ip_input.c:252
 dst_input include/net/dst.h:442 [inline]
 ip_rcv_finish+0x121/0x160 net/ipv4/ip_input.c:413
 NF_HOOK include/linux/netfilter.h:305 [inline]
 NF_HOOK include/linux/netfilter.h:299 [inline]
 ip_rcv+0x18f/0x1a0 net/ipv4/ip_input.c:523
 __netif_receive_skb_one_core+0xa7/0xe0 net/core/dev.c:5004
 __netif_receive_skb+0x37/0xf0 net/core/dev.c:5118
 netif_receive_skb_internal+0x59/0x190 net/core/dev.c:5208
 napi_skb_finish net/core/dev.c:5671 [inline]
 napi_gro_receive+0x28f/0x330 net/core/dev.c:5704
 receive_buf+0x284/0x30b0 drivers/net/virtio_net.c:1061
 virtnet_receive drivers/net/virtio_net.c:1323 [inline]
 virtnet_poll+0x436/0x7d0 drivers/net/virtio_net.c:1428
 napi_poll net/core/dev.c:6352 [inline]
 net_rx_action+0x3ae/0xa50 net/core/dev.c:6418

read to 0xffff88812ab369f8 of 8 bytes by task 7271 on cpu 0:
 tcp_recvmsg+0x470/0x1a30 net/ipv4/tcp.c:2047
 inet_recvmsg+0xbb/0x250 net/ipv4/af_inet.c:838
 sock_recvmsg_nosec net/socket.c:871 [inline]
 sock_recvmsg net/socket.c:889 [inline]
 sock_recvmsg+0x92/0xb0 net/socket.c:885
 sock_read_iter+0x15f/0x1e0 net/socket.c:967
 call_read_iter include/linux/fs.h:1864 [inline]
 new_sync_read+0x389/0x4f0 fs/read_write.c:414
 __vfs_read+0xb1/0xc0 fs/read_write.c:427
 vfs_read fs/read_write.c:461 [inline]
 vfs_read+0x143/0x2c0 fs/read_write.c:446
 ksys_read+0xd5/0x1b0 fs/read_write.c:587
 __do_sys_read fs/read_write.c:597 [inline]
 __se_sys_read fs/read_write.c:595 [inline]
 __x64_sys_read+0x4c/0x60 fs/read_write.c:595
 do_syscall_64+0xcf/0x2f0 arch/x86/entry/common.c:296
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 7271 Comm: syz-fuzzer Not tainted 5.3.0+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011

Signed-off-by: Eric Dumazet &lt;edumazet@google.com&gt;
Reported-by: syzbot &lt;syzkaller@googlegroups.com&gt;
Signed-off-by: Jakub Kicinski &lt;jakub.kicinski@netronome.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>tipc: clean up skb list lock handling on send path</title>
<updated>2019-08-18T21:01:07+00:00</updated>
<author>
<name>Jon Maloy</name>
<email>jon.maloy@ericsson.com</email>
</author>
<published>2019-08-15T14:42:50+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=e654f9f53b45fde3fcc8051830b212c7a8f36148'/>
<id>e654f9f53b45fde3fcc8051830b212c7a8f36148</id>
<content type='text'>
The policy for handling the skb list locks on the send and receive paths
is simple.

- On the send path we never need to grab the lock on the 'xmitq' list
  when the destination is an exernal node.

- On the receive path we always need to grab the lock on the 'inputq'
  list, irrespective of source node.

However, when transmitting node local messages those will eventually
end up on the receive path of a local socket, meaning that the argument
'xmitq' in tipc_node_xmit() will become the 'ínputq' argument in  the
function tipc_sk_rcv(). This has been handled by always initializing
the spinlock of the 'xmitq' list at message creation, just in case it
may end up on the receive path later, and despite knowing that the lock
in most cases never will be used.

This approach is inaccurate and confusing, and has also concealed the
fact that the stated 'no lock grabbing' policy for the send path is
violated in some cases.

We now clean up this by never initializing the lock at message creation,
instead doing this at the moment we find that the message actually will
enter the receive path. At the same time we fix the four locations
where we incorrectly access the spinlock on the send/error path.

This patch also reverts commit d12cffe9329f ("tipc: ensure head-&gt;lock
is initialised") which has now become redundant.

CC: Eric Dumazet &lt;edumazet@google.com&gt;
Reported-by: Chris Packham &lt;chris.packham@alliedtelesis.co.nz&gt;
Acked-by: Ying Xue &lt;ying.xue@windriver.com&gt;
Signed-off-by: Jon Maloy &lt;jon.maloy@ericsson.com&gt;
Reviewed-by: Xin Long &lt;lucien.xin@gmail.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The policy for handling the skb list locks on the send and receive paths
is simple.

- On the send path we never need to grab the lock on the 'xmitq' list
  when the destination is an exernal node.

- On the receive path we always need to grab the lock on the 'inputq'
  list, irrespective of source node.

However, when transmitting node local messages those will eventually
end up on the receive path of a local socket, meaning that the argument
'xmitq' in tipc_node_xmit() will become the 'ínputq' argument in  the
function tipc_sk_rcv(). This has been handled by always initializing
the spinlock of the 'xmitq' list at message creation, just in case it
may end up on the receive path later, and despite knowing that the lock
in most cases never will be used.

This approach is inaccurate and confusing, and has also concealed the
fact that the stated 'no lock grabbing' policy for the send path is
violated in some cases.

We now clean up this by never initializing the lock at message creation,
instead doing this at the moment we find that the message actually will
enter the receive path. At the same time we fix the four locations
where we incorrectly access the spinlock on the send/error path.

This patch also reverts commit d12cffe9329f ("tipc: ensure head-&gt;lock
is initialised") which has now become redundant.

CC: Eric Dumazet &lt;edumazet@google.com&gt;
Reported-by: Chris Packham &lt;chris.packham@alliedtelesis.co.nz&gt;
Acked-by: Ying Xue &lt;ying.xue@windriver.com&gt;
Signed-off-by: Jon Maloy &lt;jon.maloy@ericsson.com&gt;
Reviewed-by: Xin Long &lt;lucien.xin@gmail.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>tipc: fix unitilized skb list crash</title>
<updated>2019-07-30T21:39:36+00:00</updated>
<author>
<name>Jon Maloy</name>
<email>jon.maloy@ericsson.com</email>
</author>
<published>2019-07-30T18:19:10+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=2948a1fcd77a8bb11604387e3fc52f0ebf5729e9'/>
<id>2948a1fcd77a8bb11604387e3fc52f0ebf5729e9</id>
<content type='text'>
Our test suite somtimes provokes the following crash:

Description of problem:
[ 1092.597234] BUG: unable to handle kernel NULL pointer dereference at 00000000000000e8
[ 1092.605072] PGD 0 P4D 0
[ 1092.607620] Oops: 0000 [#1] SMP PTI
[ 1092.611118] CPU: 37 PID: 0 Comm: swapper/37 Kdump: loaded Not tainted 4.18.0-122.el8.x86_64 #1
[ 1092.619724] Hardware name: Dell Inc. PowerEdge R740/08D89F, BIOS 1.3.7 02/08/2018
[ 1092.627215] RIP: 0010:tipc_mcast_filter_msg+0x93/0x2d0 [tipc]
[ 1092.632955] Code: 0f 84 aa 01 00 00 89 cf 4d 01 ca 4c 8b 26 c1 ef 19 83 e7 0f 83 ff 0c 4d 0f 45 d1 41 8b 6a 10 0f cd 4c 39 e6 0f 84 81 01 00 00 &lt;4d&gt; 8b 9c 24 e8 00 00 00 45 8b 13 41 0f ca 44 89 d7 c1 ef 13 83 e7
[ 1092.651703] RSP: 0018:ffff929e5fa83a18 EFLAGS: 00010282
[ 1092.656927] RAX: ffff929e3fb38100 RBX: 00000000069f29ee RCX: 00000000416c0045
[ 1092.664058] RDX: ffff929e5fa83a88 RSI: ffff929e31a28420 RDI: 0000000000000000
[ 1092.671209] RBP: 0000000029b11821 R08: 0000000000000000 R09: ffff929e39b4407a
[ 1092.678343] R10: ffff929e39b4407a R11: 0000000000000007 R12: 0000000000000000
[ 1092.685475] R13: 0000000000000001 R14: ffff929e3fb38100 R15: ffff929e39b4407a
[ 1092.692614] FS:  0000000000000000(0000) GS:ffff929e5fa80000(0000) knlGS:0000000000000000
[ 1092.700702] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 1092.706447] CR2: 00000000000000e8 CR3: 000000031300a004 CR4: 00000000007606e0
[ 1092.713579] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 1092.720712] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 1092.727843] PKRU: 55555554
[ 1092.730556] Call Trace:
[ 1092.733010]  &lt;IRQ&gt;
[ 1092.735034]  tipc_sk_filter_rcv+0x7ca/0xb80 [tipc]
[ 1092.739828]  ? __kmalloc_node_track_caller+0x1cb/0x290
[ 1092.744974]  ? dev_hard_start_xmit+0xa5/0x210
[ 1092.749332]  tipc_sk_rcv+0x389/0x640 [tipc]
[ 1092.753519]  tipc_sk_mcast_rcv+0x23c/0x3a0 [tipc]
[ 1092.758224]  tipc_rcv+0x57a/0xf20 [tipc]
[ 1092.762154]  ? ktime_get_real_ts64+0x40/0xe0
[ 1092.766432]  ? tpacket_rcv+0x50/0x9f0
[ 1092.770098]  tipc_l2_rcv_msg+0x4a/0x70 [tipc]
[ 1092.774452]  __netif_receive_skb_core+0xb62/0xbd0
[ 1092.779164]  ? enqueue_entity+0xf6/0x630
[ 1092.783084]  ? kmem_cache_alloc+0x158/0x1c0
[ 1092.787272]  ? __build_skb+0x25/0xd0
[ 1092.790849]  netif_receive_skb_internal+0x42/0xf0
[ 1092.795557]  napi_gro_receive+0xba/0xe0
[ 1092.799417]  mlx5e_handle_rx_cqe+0x83/0xd0 [mlx5_core]
[ 1092.804564]  mlx5e_poll_rx_cq+0xd5/0x920 [mlx5_core]
[ 1092.809536]  mlx5e_napi_poll+0xb2/0xce0 [mlx5_core]
[ 1092.814415]  ? __wake_up_common_lock+0x89/0xc0
[ 1092.818861]  net_rx_action+0x149/0x3b0
[ 1092.822616]  __do_softirq+0xe3/0x30a
[ 1092.826193]  irq_exit+0x100/0x110
[ 1092.829512]  do_IRQ+0x85/0xd0
[ 1092.832483]  common_interrupt+0xf/0xf
[ 1092.836147]  &lt;/IRQ&gt;
[ 1092.838255] RIP: 0010:cpuidle_enter_state+0xb7/0x2a0
[ 1092.843221] Code: e8 3e 79 a5 ff 80 7c 24 03 00 74 17 9c 58 0f 1f 44 00 00 f6 c4 02 0f 85 d7 01 00 00 31 ff e8 a0 6b ab ff fb 66 0f 1f 44 00 00 &lt;48&gt; b8 ff ff ff ff f3 01 00 00 4c 29 f3 ba ff ff ff 7f 48 39 c3 7f
[ 1092.861967] RSP: 0018:ffffaa5ec6533e98 EFLAGS: 00000246 ORIG_RAX: ffffffffffffffdd
[ 1092.869530] RAX: ffff929e5faa3100 RBX: 000000fe63dd2092 RCX: 000000000000001f
[ 1092.876665] RDX: 000000fe63dd2092 RSI: 000000003a518aaa RDI: 0000000000000000
[ 1092.883795] RBP: 0000000000000003 R08: 0000000000000004 R09: 0000000000022940
[ 1092.890929] R10: 0000040cb0666b56 R11: ffff929e5faa20a8 R12: ffff929e5faade78
[ 1092.898060] R13: ffffffffb59258f8 R14: 000000fe60f3228d R15: 0000000000000000
[ 1092.905196]  ? cpuidle_enter_state+0x92/0x2a0
[ 1092.909555]  do_idle+0x236/0x280
[ 1092.912785]  cpu_startup_entry+0x6f/0x80
[ 1092.916715]  start_secondary+0x1a7/0x200
[ 1092.920642]  secondary_startup_64+0xb7/0xc0
[...]

The reason is that the skb list tipc_socket::mc_method.deferredq only
is initialized for connectionless sockets, while nothing stops arriving
multicast messages from being filtered by connection oriented sockets,
with subsequent access to the said list.

We fix this by initializing the list unconditionally at socket creation.
This eliminates the crash, while the message still is dropped further
down in tipc_sk_filter_rcv() as it should be.

Reported-by: Li Shuang &lt;shuali@redhat.com&gt;
Signed-off-by: Jon Maloy &lt;jon.maloy@ericsson.com&gt;
Reviewed-by: Xin Long &lt;lucien.xin@gmail.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Our test suite somtimes provokes the following crash:

Description of problem:
[ 1092.597234] BUG: unable to handle kernel NULL pointer dereference at 00000000000000e8
[ 1092.605072] PGD 0 P4D 0
[ 1092.607620] Oops: 0000 [#1] SMP PTI
[ 1092.611118] CPU: 37 PID: 0 Comm: swapper/37 Kdump: loaded Not tainted 4.18.0-122.el8.x86_64 #1
[ 1092.619724] Hardware name: Dell Inc. PowerEdge R740/08D89F, BIOS 1.3.7 02/08/2018
[ 1092.627215] RIP: 0010:tipc_mcast_filter_msg+0x93/0x2d0 [tipc]
[ 1092.632955] Code: 0f 84 aa 01 00 00 89 cf 4d 01 ca 4c 8b 26 c1 ef 19 83 e7 0f 83 ff 0c 4d 0f 45 d1 41 8b 6a 10 0f cd 4c 39 e6 0f 84 81 01 00 00 &lt;4d&gt; 8b 9c 24 e8 00 00 00 45 8b 13 41 0f ca 44 89 d7 c1 ef 13 83 e7
[ 1092.651703] RSP: 0018:ffff929e5fa83a18 EFLAGS: 00010282
[ 1092.656927] RAX: ffff929e3fb38100 RBX: 00000000069f29ee RCX: 00000000416c0045
[ 1092.664058] RDX: ffff929e5fa83a88 RSI: ffff929e31a28420 RDI: 0000000000000000
[ 1092.671209] RBP: 0000000029b11821 R08: 0000000000000000 R09: ffff929e39b4407a
[ 1092.678343] R10: ffff929e39b4407a R11: 0000000000000007 R12: 0000000000000000
[ 1092.685475] R13: 0000000000000001 R14: ffff929e3fb38100 R15: ffff929e39b4407a
[ 1092.692614] FS:  0000000000000000(0000) GS:ffff929e5fa80000(0000) knlGS:0000000000000000
[ 1092.700702] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 1092.706447] CR2: 00000000000000e8 CR3: 000000031300a004 CR4: 00000000007606e0
[ 1092.713579] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 1092.720712] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 1092.727843] PKRU: 55555554
[ 1092.730556] Call Trace:
[ 1092.733010]  &lt;IRQ&gt;
[ 1092.735034]  tipc_sk_filter_rcv+0x7ca/0xb80 [tipc]
[ 1092.739828]  ? __kmalloc_node_track_caller+0x1cb/0x290
[ 1092.744974]  ? dev_hard_start_xmit+0xa5/0x210
[ 1092.749332]  tipc_sk_rcv+0x389/0x640 [tipc]
[ 1092.753519]  tipc_sk_mcast_rcv+0x23c/0x3a0 [tipc]
[ 1092.758224]  tipc_rcv+0x57a/0xf20 [tipc]
[ 1092.762154]  ? ktime_get_real_ts64+0x40/0xe0
[ 1092.766432]  ? tpacket_rcv+0x50/0x9f0
[ 1092.770098]  tipc_l2_rcv_msg+0x4a/0x70 [tipc]
[ 1092.774452]  __netif_receive_skb_core+0xb62/0xbd0
[ 1092.779164]  ? enqueue_entity+0xf6/0x630
[ 1092.783084]  ? kmem_cache_alloc+0x158/0x1c0
[ 1092.787272]  ? __build_skb+0x25/0xd0
[ 1092.790849]  netif_receive_skb_internal+0x42/0xf0
[ 1092.795557]  napi_gro_receive+0xba/0xe0
[ 1092.799417]  mlx5e_handle_rx_cqe+0x83/0xd0 [mlx5_core]
[ 1092.804564]  mlx5e_poll_rx_cq+0xd5/0x920 [mlx5_core]
[ 1092.809536]  mlx5e_napi_poll+0xb2/0xce0 [mlx5_core]
[ 1092.814415]  ? __wake_up_common_lock+0x89/0xc0
[ 1092.818861]  net_rx_action+0x149/0x3b0
[ 1092.822616]  __do_softirq+0xe3/0x30a
[ 1092.826193]  irq_exit+0x100/0x110
[ 1092.829512]  do_IRQ+0x85/0xd0
[ 1092.832483]  common_interrupt+0xf/0xf
[ 1092.836147]  &lt;/IRQ&gt;
[ 1092.838255] RIP: 0010:cpuidle_enter_state+0xb7/0x2a0
[ 1092.843221] Code: e8 3e 79 a5 ff 80 7c 24 03 00 74 17 9c 58 0f 1f 44 00 00 f6 c4 02 0f 85 d7 01 00 00 31 ff e8 a0 6b ab ff fb 66 0f 1f 44 00 00 &lt;48&gt; b8 ff ff ff ff f3 01 00 00 4c 29 f3 ba ff ff ff 7f 48 39 c3 7f
[ 1092.861967] RSP: 0018:ffffaa5ec6533e98 EFLAGS: 00000246 ORIG_RAX: ffffffffffffffdd
[ 1092.869530] RAX: ffff929e5faa3100 RBX: 000000fe63dd2092 RCX: 000000000000001f
[ 1092.876665] RDX: 000000fe63dd2092 RSI: 000000003a518aaa RDI: 0000000000000000
[ 1092.883795] RBP: 0000000000000003 R08: 0000000000000004 R09: 0000000000022940
[ 1092.890929] R10: 0000040cb0666b56 R11: ffff929e5faa20a8 R12: ffff929e5faade78
[ 1092.898060] R13: ffffffffb59258f8 R14: 000000fe60f3228d R15: 0000000000000000
[ 1092.905196]  ? cpuidle_enter_state+0x92/0x2a0
[ 1092.909555]  do_idle+0x236/0x280
[ 1092.912785]  cpu_startup_entry+0x6f/0x80
[ 1092.916715]  start_secondary+0x1a7/0x200
[ 1092.920642]  secondary_startup_64+0xb7/0xc0
[...]

The reason is that the skb list tipc_socket::mc_method.deferredq only
is initialized for connectionless sockets, while nothing stops arriving
multicast messages from being filtered by connection oriented sockets,
with subsequent access to the said list.

We fix this by initializing the list unconditionally at socket creation.
This eliminates the crash, while the message still is dropped further
down in tipc_sk_filter_rcv() as it should be.

Reported-by: Li Shuang &lt;shuali@redhat.com&gt;
Signed-off-by: Jon Maloy &lt;jon.maloy@ericsson.com&gt;
Reviewed-by: Xin Long &lt;lucien.xin@gmail.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>tipc: fix hanging clients using poll with EPOLLOUT flag</title>
<updated>2019-05-09T16:26:09+00:00</updated>
<author>
<name>Parthasarathy Bhuvaragan</name>
<email>parthasarathy.bhuvaragan@gmail.com</email>
</author>
<published>2019-05-09T05:13:42+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=ff946833b70e0c7f93de9a3f5b329b5ae2287b38'/>
<id>ff946833b70e0c7f93de9a3f5b329b5ae2287b38</id>
<content type='text'>
commit 517d7c79bdb398 ("tipc: fix hanging poll() for stream sockets")
introduced a regression for clients using non-blocking sockets.
After the commit, we send EPOLLOUT event to the client even in
TIPC_CONNECTING state. This causes the subsequent send() to fail
with ENOTCONN, as the socket is still not in TIPC_ESTABLISHED state.

In this commit, we:
- improve the fix for hanging poll() by replacing sk_data_ready()
  with sk_state_change() to wake up all clients.
- revert the faulty updates introduced by commit 517d7c79bdb398
  ("tipc: fix hanging poll() for stream sockets").

Fixes: 517d7c79bdb398 ("tipc: fix hanging poll() for stream sockets")
Signed-off-by: Parthasarathy Bhuvaragan &lt;parthasarathy.bhuvaragan@gmail.com&gt;
Acked-by: Jon Maloy &lt;jon.maloy@ericsson.se&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
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<pre>
commit 517d7c79bdb398 ("tipc: fix hanging poll() for stream sockets")
introduced a regression for clients using non-blocking sockets.
After the commit, we send EPOLLOUT event to the client even in
TIPC_CONNECTING state. This causes the subsequent send() to fail
with ENOTCONN, as the socket is still not in TIPC_ESTABLISHED state.

In this commit, we:
- improve the fix for hanging poll() by replacing sk_data_ready()
  with sk_state_change() to wake up all clients.
- revert the faulty updates introduced by commit 517d7c79bdb398
  ("tipc: fix hanging poll() for stream sockets").

Fixes: 517d7c79bdb398 ("tipc: fix hanging poll() for stream sockets")
Signed-off-by: Parthasarathy Bhuvaragan &lt;parthasarathy.bhuvaragan@gmail.com&gt;
Acked-by: Jon Maloy &lt;jon.maloy@ericsson.se&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
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