CVE request Qemu: usb: ehci null pointer dereference in ehci_caps_write

[P J P <ppandit () redhat com>]

  Hello,

Qemu emulator built with the USB EHCI emulation support is vulnerable to a 
null pointer dereference flaw. It could occur when an application attempts to 
write to EHCI capabilities registers.

A privileged user inside quest could use this flaw to crash the Qemu process 
instance resulting in DoS.

Upstream patch:
---------------
  -> https://lists.gnu.org/archive/html/qemu-devel/2016-01/msg05899.html

Reference:
----------
  -> https://bugzilla.redhat.com/show_bug.cgi?id=1301643

This issue was discovered by Mr Zuozhi Fzz of Alibaba Inc.

Thank you.
--
Prasad J Pandit / Red Hat Product Security Team
47AF CE69 3A90 54AA 9045 1053 DD13 3D32 FE5B 041F