Tung Nguyen d34910e175 tipc: fix duplicate SYN messages under link congestion
Scenario:
1. A client socket initiates a SYN message to a listening socket.
2. The send link is congested, the SYN message is put in the
send link and a wakeup message is put in wakeup queue.
3. The congestion situation is abated, the wakeup message is
pulled out of the wakeup queue. Function tipc_sk_push_backlog()
is called to send out delayed messages by Nagle. However,
the client socket is still in CONNECTING state. So, it sends
the SYN message in the socket write queue to the listening socket
again.
4. The listening socket receives the first SYN message and creates
first server socket. The client socket receives ACK- and establishes
a connection to the first server socket. The client socket closes
its connection with the first server socket.
5. The listening socket receives the second SYN message and creates
second server socket. The second server socket sends ACK- to the
client socket, but it has been closed. It results in connection
reset error when reading from the server socket in user space.

Solution: return from function tipc_sk_push_backlog() immediately
if there is pending SYN message in the socket write queue.

Fixes: c0bceb97db9e ("tipc: add smart nagle feature")
Signed-off-by: Tung Nguyen <tung.q.nguyen@dektech.com.au>
Acked-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-11-28 23:09:15 -08:00
2019-11-28 11:16:43 -08:00
2019-11-25 11:37:01 -08:00
2019-11-27 17:45:48 -08:00
2019-11-28 10:43:39 -08:00
2019-11-28 11:16:43 -08:00
2019-11-28 10:57:12 -08:00
2019-11-27 11:42:01 -08:00
2019-11-27 17:45:48 -08:00
2019-11-26 20:04:35 -08:00
2019-09-22 10:34:46 -07:00
2019-11-27 17:45:48 -08:00
2019-11-24 16:32:01 -08:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.
Description
Linux kernel source tree
Readme 3.5 GiB
Languages
C 97.5%
Assembly 1%
Shell 0.6%
Python 0.3%
Makefile 0.3%