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Tan Hu a53b42c118 ipvs: fix race between ip_vs_conn_new() and ip_vs_del_dest()
We came across infinite loop in ipvs when using ipvs in docker
env.

When ipvs receives new packets and cannot find an ipvs connection,
it will create a new connection, then if the dest is unavailable
(i.e. IP_VS_DEST_F_AVAILABLE), the packet will be dropped sliently.

But if the dropped packet is the first packet of this connection,
the connection control timer never has a chance to start and the
ipvs connection cannot be released. This will lead to memory leak, or
infinite loop in cleanup_net() when net namespace is released like
this:

    ip_vs_conn_net_cleanup at ffffffffa0a9f31a [ip_vs]
    __ip_vs_cleanup at ffffffffa0a9f60a [ip_vs]
    ops_exit_list at ffffffff81567a49
    cleanup_net at ffffffff81568b40
    process_one_work at ffffffff810a851b
    worker_thread at ffffffff810a9356
    kthread at ffffffff810b0b6f
    ret_from_fork at ffffffff81697a18

race condition:
    CPU1                           CPU2
    ip_vs_in()
      ip_vs_conn_new()
                                   ip_vs_del_dest()
                                     __ip_vs_unlink_dest()
                                       ~IP_VS_DEST_F_AVAILABLE
      cp->dest && !IP_VS_DEST_F_AVAILABLE
      __ip_vs_conn_put
    ...
    cleanup_net  ---> infinite looping

Fix this by checking whether the timer already started.

Signed-off-by: Tan Hu <tan.hu@zte.com.cn>
Reviewed-by: Jiang Biao <jiang.biao2@zte.com.cn>
Acked-by: Julian Anastasov <ja@ssi.bg>
Acked-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-08-16 19:36:51 +02:00
Documentation Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2018-08-15 15:04:25 -07:00
LICENSES LICENSES: Add Linux-OpenIB license text 2018-04-27 16:41:53 -06:00
arch Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2018-08-15 15:04:25 -07:00
block for-4.19/block-20180812 2018-08-14 10:23:25 -07:00
certs certs/blacklist: fix const confusion 2018-06-26 09:43:03 -07:00
crypto net: simplify sock_poll_wait 2018-07-30 09:10:25 -07:00
drivers Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2018-08-15 15:04:25 -07:00
firmware kbuild: remove all dummy assignments to obj- 2017-11-18 11:46:06 +09:00
fs Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2018-08-15 15:04:25 -07:00
include Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2018-08-15 15:04:25 -07:00
init Consolidation of Kconfig files by Christoph Hellwig. 2018-08-15 13:05:12 -07:00
ipc Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2018-08-15 15:04:25 -07:00
kernel Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2018-08-15 15:04:25 -07:00
lib Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2018-08-15 15:04:25 -07:00
mm Consolidation of Kconfig files by Christoph Hellwig. 2018-08-15 13:05:12 -07:00
net ipvs: fix race between ip_vs_conn_new() and ip_vs_del_dest() 2018-08-16 19:36:51 +02:00
samples Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2018-08-15 15:04:25 -07:00
scripts Kconfig updates for v4.19 2018-08-15 12:50:10 -07:00
security Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2018-08-15 15:04:25 -07:00
sound ASoC: Updates for v4.19 2018-08-13 12:12:31 +02:00
tools Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2018-08-15 15:04:25 -07:00
usr kbuild: rename built-in.o to built-in.a 2018-03-26 02:01:19 +09:00
virt arm64 updates for 4.19 2018-08-14 16:39:13 -07:00
.clang-format clang-format: add configuration file 2018-04-11 10:28:35 -07:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.get_maintainer.ignore
.gitattributes .gitattributes: set git diff driver for C source code files 2016-10-07 18:46:30 -07:00
.gitignore Kbuild updates for v4.17 (2nd) 2018-04-15 17:21:30 -07:00
.mailmap mailmap: remap some of my email addresses to kernel.org address 2018-08-06 13:15:16 -04:00
COPYING COPYING: use the new text with points to the license files 2018-03-23 12:41:45 -06:00
CREDITS MAINTAINERS/CREDITS: Drop METAG ARCHITECTURE 2018-03-05 16:34:24 +00:00
Kbuild Kbuild updates for v4.15 2017-11-17 17:45:29 -08:00
Kconfig kconfig: move the "Executable file formats" menu to fs/Kconfig.binfmt 2018-08-02 08:06:55 +09:00
MAINTAINERS Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2018-08-15 15:04:25 -07:00
Makefile Kconfig updates for v4.19 2018-08-15 12:50:10 -07:00
README Docs: Added a pointer to the formatted docs to README 2018-03-21 09:02:53 -06:00

README

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.
See Documentation/00-INDEX for a list of what is contained in each file.

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.