linux-stable.git/net/tipc/socket.c, branch v4.19.136

tipc: clean up skb list lock handling on send path

2020-07-29T08:16:47+00:00

commit e654f9f53b45fde3fcc8051830b212c7a8f36148 upstream.

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->lock
is initialised") which has now become redundant.

CC: Eric Dumazet 
Reported-by: Chris Packham 
Acked-by: Ying Xue 
Signed-off-by: Jon Maloy 
Reviewed-by: Xin Long 
Signed-off-by: David S. Miller 
[acj: backport v4.19 -stable
- adjust context
- skipped the hunk modifying non-existent function tipc_mcast_send_sync
- additional comment ]
Signed-off-by: Aviraj CJ 
Signed-off-by: Greg Kroah-Hartman

tipc: fix wrong timeout input for tipc_wait_for_cond()

2020-01-27T13:49:52+00:00

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 
Acked-by: Jon Maloy 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

net: use skb_queue_empty_lockless() in poll() handlers

2019-11-10T10:27:48+00:00

[ Upstream commit 3ef7cf57c72f32f61e97f8fa401bc39ea1f1a5d4 ]

Many poll() handlers are lockless. Using skb_queue_empty_lockless()
instead of skb_queue_empty() is more appropriate.

Signed-off-by: Eric Dumazet 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

tipc: fix hanging clients using poll with EPOLLOUT flag

2019-05-16T17:41:31+00:00

[ Upstream commit ff946833b70e0c7f93de9a3f5b329b5ae2287b38 ]

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 
Acked-by: Jon Maloy 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

tipc: allow service ranges to be connect()'ed on RDM/DGRAM

2019-04-03T04:26:18+00:00

[ Upstream commit ea239314fe42ace880bdd834256834679346c80e ]

We move the check that prevents connecting service ranges to after
the RDM/DGRAM check, and move address sanity control to a separate
function that also validates the service range.

Fixes: 23998835be98 ("tipc: improve address sanity check in tipc_connect()")
Signed-off-by: Erik Hugne 
Signed-off-by: Jon Maloy 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

tipc: fix race condition causing hung sendto

2019-03-10T06:17:18+00:00

[ Upstream commit bfd07f3dd4f111b884d7922b37eb239280f83d8c ]

When sending multicast messages via blocking socket,
if sending link is congested (tsk->cong_link_cnt is set to 1),
the sending thread will be put into sleeping state. However,
tipc_sk_filter_rcv() is called under socket spin lock but
tipc_wait_for_cond() is not. So, there is no guarantee that
the setting of tsk->cong_link_cnt to 0 in tipc_sk_proto_rcv() in
CPU-1 will be perceived by CPU-0. If that is the case, the sending
thread in CPU-0 after being waken up, will continue to see
tsk->cong_link_cnt as 1 and put the sending thread into sleeping
state again. The sending thread will sleep forever.

CPU-0                                | CPU-1
tipc_wait_for_cond()                 |
{                                    |
 // condition_ = !tsk->cong_link_cnt |
 while ((rc_ = !(condition_))) {     |
  ...                                |
  release_sock(sk_);                 |
  wait_woken();                      |
                                     | if (!sock_owned_by_user(sk))
                                     |  tipc_sk_filter_rcv()
                                     |  {
                                     |   ...
                                     |   tipc_sk_proto_rcv()
                                     |   {
                                     |    ...
                                     |    tsk->cong_link_cnt--;
                                     |    ...
                                     |    sk->sk_write_space(sk);
                                     |    ...
                                     |   }
                                     |   ...
                                     |  }
  sched_annotate_sleep();            |
  lock_sock(sk_);                    |
  remove_wait_queue();               |
 }                                   |
}                                    |

This commit fixes it by adding memory barrier to tipc_sk_proto_rcv()
and tipc_wait_for_cond().

Acked-by: Jon Maloy 
Signed-off-by: Tung Nguyen 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

tipc: fix RDM/DGRAM connect() regression

2019-03-10T06:17:17+00:00

[ Upstream commit 0e63208915a8d7590d0a6218dadb2a6a00ac705a ]

Fix regression bug introduced in
commit 365ad353c256 ("tipc: reduce risk of user starvation during link
congestion")

Only signal -EDESTADDRREQ for RDM/DGRAM if we don't have a cached
sockaddr.

Fixes: 365ad353c256 ("tipc: reduce risk of user starvation during link congestion")
Signed-off-by: Erik Hugne 
Signed-off-by: Jon Maloy 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

tipc: check group dests after tipc_wait_for_cond()

2019-01-09T16:38:34+00:00

[ Upstream commit 3c6306d44082ef007a258ae1b86ea58e6974ee3f ]

Similar to commit 143ece654f9f ("tipc: check tsk->group in tipc_wait_for_cond()")
we have to reload grp->dests too after we re-take the sock lock.
This means we need to move the dsts check after tipc_wait_for_cond()
too.

Fixes: 75da2163dbb6 ("tipc: introduce communication groups")
Reported-and-tested-by: syzbot+99f20222fc5018d2b97a@syzkaller.appspotmail.com
Cc: Ying Xue 
Cc: Jon Maloy 
Signed-off-by: Cong Wang 
Acked-by: Jon Maloy 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

tipc: use lock_sock() in tipc_sk_reinit()

2019-01-09T16:38:34+00:00

[ Upstream commit 15ef70e286176165d28b0b8a969b422561a68dfc ]

lock_sock() must be used in process context to be race-free with
other lock_sock() callers, for example, tipc_release(). Otherwise
using the spinlock directly can't serialize a parallel tipc_release().

As it is blocking, we have to hold the sock refcnt before
rhashtable_walk_stop() and release it after rhashtable_walk_start().

Fixes: 07f6c4bc048a ("tipc: convert tipc reference table to use generic rhashtable")
Reported-by: Dmitry Vyukov 
Cc: Ying Xue 
Cc: Jon Maloy 
Signed-off-by: Cong Wang 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

tipc: check tsk->group in tipc_wait_for_cond()

2019-01-09T16:38:33+00:00

[ Upstream commit 143ece654f9f5b37bedea252a990be37e48ae3a5 ]

tipc_wait_for_cond() drops socket lock before going to sleep,
but tsk->group could be freed right after that release_sock().
So we have to re-check and reload tsk->group after it wakes up.

After this patch, tipc_wait_for_cond() returns -ERESTARTSYS when
tsk->group is NULL, instead of continuing with the assumption of
a non-NULL tsk->group.

(It looks like 'dsts' should be re-checked and reloaded too, but
it is a different bug.)

Similar for tipc_send_group_unicast() and tipc_send_group_anycast().

Reported-by: syzbot+10a9db47c3a0e13eb31c@syzkaller.appspotmail.com
Fixes: b7d42635517f ("tipc: introduce flow control for group broadcast messages")
Fixes: ee106d7f942d ("tipc: introduce group anycast messaging")
Fixes: 27bd9ec027f3 ("tipc: introduce group unicast messaging")
Cc: Ying Xue 
Cc: Jon Maloy 
Signed-off-by: Cong Wang 
Acked-by: Ying Xue 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman