Help: QXcbEventReader segfault

xiaoyj22200837

Environment : ubuntu 14.04 , QT 5.2.1
Operation: Press Key "ESC" to switch the UI Dialog, then APP crash.
Stack log:
[12-16 10:35:33:305][APP][E]: thread:3945, Caught error signal: 11
[12-16 10:35:33:305][APP][E]: =/home/root/sono(_Z15RecLogResultActiP9siginfo_tPv+0x4f) [0x764b4f]
[12-16 10:35:33:305][APP][E]: =/lib/x86_64-linux-gnu/libpthread.so.0(+0x10330) [0x7f673c769330]
[12-16 10:35:33:305][APP][E]: =/lib/x86_64-linux-gnu/libc.so.6(__poll+0x2d) [0x7f673bc6184d]
[12-16 10:35:33:305][APP][E]: =/usr/lib/x86_64-linux-gnu/libxcb.so.1(+0x9b72) [0x7f6735769b72]
[12-16 10:35:33:305][APP][E]: =/usr/lib/x86_64-linux-gnu/libxcb.so.1(xcb_wait_for_event+0x3f) [0x7f673576b64f]
[12-16 10:35:33:305][APP][E]: =/usr/lib/x86_64-linux-gnu/qt5/plugins/platforms/libqxcb.so(+0x2e729) [0x7f6732689729]
[12-16 10:35:33:305][APP][E]: =/usr/lib/x86_64-linux-gnu/libQt5Core.so.5(+0x93233) [0x7f673ca0a233]
[12-16 10:35:33:305][APP][E]: =/lib/x86_64-linux-gnu/libpthread.so.0(+0x8184) [0x7f673c761184]
[12-16 10:35:33:305][APP][E]: =/lib/x86_64-linux-gnu/libc.so.6(clone+0x6d) [0x7f673bc6ebed]

Kernel log:
Dec 16 10:35:33 sono kernel: [ 5774.844736] QXcbEventReader[3945]: segfault at 7f6732689729 ip 00007f6732689729 sp 00007f672fa5ee60 error 14 in libXdmcp.so.6.0.0[7f6732908000+5000]

I has no idea about this problem, did anyone else come across this? thanks.