today my xserver locked up while typing: it was just hanging, not even the mouse did move (no restart).  in Xorg.0.log I got the following information:

...
(II) 3rd Button detected: disabling emulate3Button
BOGUS LENGTH in write keyboard desc, expected 5140, got 5148

Backtrace:
0: /usr/bin/Xorg(xf86SigHandler+0x65) [0x47eca5]
1: /lib64/libc.so.6 [0x7fd167be26e0]
2: /lib64/libc.so.6 [0x7fd167c254ca]
3: /lib64/libc.so.6(cfree+0x76) [0x7fd167c25c76]
4: /usr/bin/Xorg [0x540475]
5: /usr/bin/Xorg(ProcXkbGetKbdByName+0xe24) [0x546dd4]
6: /usr/bin/Xorg(Dispatch+0x364) [0x44c444]
7: /usr/bin/Xorg(main+0x45d) [0x43260d]
8: /lib64/libc.so.6(__libc_start_main+0xe6) [0x7fd167bce586]
9: /usr/bin/Xorg [0x4319e9]

the full backtrace from attached gdb while looping looks like this:


(no debugging symbols found)
0x00007fd167c8ee6e in ?? () from /lib64/libc.so.6
(gdb) where
#0  0x00007fd167c8ee6e in ?? () from /lib64/libc.so.6
#1  0x00007fd167c2963e in ?? () from /lib64/libc.so.6
#2  0x00007fd167c25c6b in free () from /lib64/libc.so.6
#3  0x000000000049685d in XisbFree ()
#4  0x00007fd1658ae47f in ?? () from /usr/lib64/xorg/modules//input/mouse_drv.so
#5  0x0000000000445273 in DisableDevice ()
#6  0x00000000004455ee in RemoveDevice ()
#7  0x0000000000495f63 in DeleteInputDeviceRequest ()
#8  0x0000000000445769 in CloseDownDevices ()
#9  0x00000000004f6573 in AbortServer ()
#10 0x00000000004f6c45 in FatalError ()
#11 0x000000000047ecf8 in xf86SigHandler ()
#12 <signal handler called>
#13 0x00007fd167c254ca in ?? () from /lib64/libc.so.6
#14 0x00007fd167c25c76 in free () from /lib64/libc.so.6
#15 0x0000000000540475 in ?? ()
#16 0x0000000000546dd4 in ProcXkbGetKbdByName ()
#17 0x000000000044c444 in Dispatch ()
#18 0x000000000043260d in main ()
(gdb) q


version information: xorg-x11-server-7.4-17.4.1