CVE-2020-25084 QEMU: usb: use-after-free issue while setting up packet

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

  Hello,

An use-after-free issue was found in USB(xHCI/eHCI) controller emulators of 
QEMU. It occurs while setting up USB packet, as usb_packet_map() routine may 
return an error, which was not checked. A guest user/process may use this flaw 
to crash the QEMU process resulting in DoS scenario.

Upstream patches:
-----------------
  -> https://lists.nongnu.org/archive/html/qemu-devel/2020-08/msg08050.html
  -> https://lists.nongnu.org/archive/html/qemu-devel/2020-08/msg08043.html

References:
-----------
  -> https://ruhr-uni-bochum.sciebo.de/s/NNWP2GfwzYKeKwE?path=%2Fxhci_uaf_2

* This issue was reported by Sergej Schumilo, Cornelius Aschermann, Simon
  Wrner of Ruhr-University Bochum.

* 'CVE-2020-25084' assigned via https://cveform.mitre.org


Thank you.
--
Prasad J Pandit / Red Hat Product Security Team
8685 545E B54C 486B C6EB 271E E285 8B5A F050 DE8D