linux/include/net/sctp
Marcelo Ricardo Leitner 2d45a02d01 sctp: fix ASCONF list handling
->auto_asconf_splist is per namespace and mangled by functions like
sctp_setsockopt_auto_asconf() which doesn't guarantee any serialization.

Also, the call to inet_sk_copy_descendant() was backuping
->auto_asconf_list through the copy but was not honoring
->do_auto_asconf, which could lead to list corruption if it was
different between both sockets.

This commit thus fixes the list handling by using ->addr_wq_lock
spinlock to protect the list. A special handling is done upon socket
creation and destruction for that. Error handlig on sctp_init_sock()
will never return an error after having initialized asconf, so
sctp_destroy_sock() can be called without addrq_wq_lock. The lock now
will be take on sctp_close_sock(), before locking the socket, so we
don't do it in inverse order compared to sctp_addr_wq_timeout_handler().

Instead of taking the lock on sctp_sock_migrate() for copying and
restoring the list values, it's preferred to avoid rewritting it by
implementing sctp_copy_descendant().

Issue was found with a test application that kept flipping sysctl
default_auto_asconf on and off, but one could trigger it by issuing
simultaneous setsockopt() calls on multiple sockets or by
creating/destroying sockets fast enough. This is only triggerable
locally.

Fixes: 9f7d653b67 ("sctp: Add Auto-ASCONF support (core).")
Reported-by: Ji Jianwen <jiji@redhat.com>
Suggested-by: Neil Horman <nhorman@tuxdriver.com>
Suggested-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-06-14 12:55:49 -07:00
..
auth.h include/net/: Fix FSF address in file headers 2013-12-06 12:37:56 -05:00
checksum.h include/net/: Fix FSF address in file headers 2013-12-06 12:37:56 -05:00
command.h sctp: handle association restarts when the socket is closed. 2014-10-06 00:21:45 -04:00
constants.h net: sctp: Rename SCTP_XMIT_NAGLE_DELAY to SCTP_XMIT_DELAY 2014-07-22 13:32:11 -07:00
sctp.h sctp: Fix mangled IPv4 addresses on a IPv6 listening socket 2015-05-27 14:15:26 -04:00
sm.h new helper: memcpy_from_msg() 2014-11-24 04:28:48 -05:00
structs.h sctp: fix ASCONF list handling 2015-06-14 12:55:49 -07:00
tsnmap.h sctp: Fix FSF address in file headers 2013-12-06 12:37:56 -05:00
ulpevent.h net: sctp: implement rfc6458, 5.3.6. SCTP_NXTINFO cmsg support 2014-07-16 14:40:03 -07:00
ulpqueue.h sctp: Fix FSF address in file headers 2013-12-06 12:37:56 -05:00