CVE-2017-15118 Qemu: stack buffer overflow in NBD server triggered via long export name

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

  Hello,

A stack based buffer overflow vulnerability was found in NBD server 
implementation in Qemu allowing client to request an export name of size up to 
4096 bytes, which in fact should be limited to 256 bytes, allowing to cause 
out-of-bounds stack write in Qemu process.

If NBD server requires TLS, the attacker cannot trigger the buffer overflow 
without first successfully negotiating TLS.

Upstream patch:
---------------
  -> https://lists.gnu.org/archive/html/qemu-devel/2017-11/msg05045.html

Reference:
----------
  ->https://bugzilla.redhat.com/show_bug.cgi?id=1516922

Thank you.
--
Prasad J Pandit / Red Hat Product Security Team
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