kernel security and bug fix update

[2.6.32-642.4.2]

• [net] tcp: make challenge acks less predictable (Florian Westphal) [1355606 1355607] {CVE-2016-5696}
  [2.6.32-642.4.1]
• [ipmi] Remove smi_msg from waiting_rcv_msgs list before handle_one_recv_msg() (David Arcari) [1355980 1347189]
• [fs] ext4: Remove useless spinlock in ext4_getattr() (Lukas Czerner) [1355981 1315933]
• [net] tcp: increase size at which tcp_bound_to_half_wnd bounds to > TCP_MSS_DEFAULT (Davide Caratti) [1354446 1349776]
• [net] tcp: Prevent overzealous packetization by SWS logic (Davide Caratti) [1354446 1349776]
• [fs] configfs: fix race between dentry put and lookup (Robert S Peterson) [1353828 1333448]
• [drm] move idr2 implementation to lib (Milos Vyletel) [1353827 1316790]
• [fs] cifs: Create dedicated keyring for spnego operations (Scott Mayhew) [1351670 1267754]
• [infiniband] srp: Fix backport error in ib_srp::srp_queuecommand (Don Dutile) [1348062 1321094]
• [fs] gfs2: don’t set rgrp gl_object until it’s inserted into rgrp tree (Robert S Peterson) [1347539 1344740]
• [sched] avoid kernel panic during power off (Frank Ramsay) [1343894 1313035]