CVE-2015-7512 Qemu: net: pcnet: buffer overflow in non-loopback mode

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

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  Hello,

The AMD PC-Net II emulator(hw/net/pcnet.c), while receiving packets from a 
remote host(non-loopback mode), fails to validate the received data size, thus 
resulting in a buffer overflow issue. It could potentially lead to arbitrary 
code execution on the host, with privileges of the Qemu process. It requires 
the guest NIC to have larger MTU limit.

A remote user could use this flaw to crash the guest instance resulting in DoS 
or potentially execute arbitrary code on a remote host with privileges of the 
Qemu process.

Upstream fix:
- -------------
  -> https://lists.gnu.org/archive/html/qemu-devel/2015-11/msg06341.html

CVE-2015-7512 has been assigned to this issue by Red Hat Inc.

This issue was independently discovered by Ling Liu of Qihoo 360 Inc. and 
Jason Wang of Red Hat Inc.

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

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