CVE-2021-3416 QEMU: net: infinite loop in loopback mode may lead tostack overflow

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

  Hello,

A potential stack overflow via infinite loop issue was found in various NIC 
emulators of QEMU. The said issue occurs in loopback mode of a NIC wherein 
reentrant DMA checks may get bypassed. A guest user/process may use this flaw 
to consume cpu cycles or crash the QEMU process on the host resulting in DoS 
scenario.

Upstream patch:
---------------
  -> https://lists.gnu.org/archive/html/qemu-devel/2021-02/msg07431.html
  -> https://lists.gnu.org/archive/html/qemu-devel/2021-02/msg07484.html

'CVE-2021-3416' assigned via Red Hat Inc.

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