Why system logs are showing many call traces with 'tcp_fastretrans_alert' ?

Issue

• After updating to RHEL 6.4 kernel-2.6.32-358.14.1.el6, system logs are full of call traces like below:

------------[ cut here ]------------
WARNING: at net/ipv4/tcp_input.c:2976 tcp_fastretrans_alert+0x3a1/0x10f0() (Tainted: G        W  ---------------   )
Pid: 4471, comm: processname Tainted: G        W  ---------------    2.6.32-358.14.1.el6.x86_64 #1
Call Trace:
 [<ffffffff8106e307>] ? warn_slowpath_common+0x87/0xc0
 [<ffffffff8106e35a>] ? warn_slowpath_null+0x1a/0x20
 [<ffffffff81495db1>] ? tcp_fastretrans_alert+0x3a1/0x10f0
 [<ffffffff8149718c>] ? tcp_ack+0x68c/0x12c0
 [<ffffffff81499d00>] ? tcp_transmit_skb+0x400/0x7b0
 [<ffffffff8149b6a9>] ? tcp_send_ack+0xd9/0x120