qemu -- stack buffer overflow while parsing SCSI commands

Prasad J Pandit, Red Hat Product Security Team, reports:

Qemu emulator built with the SCSI device emulation support is
vulnerable to a stack buffer overflow issue. It could occur while
parsing SCSI command descriptor block with an invalid operation
code.
A privileged(CAP_SYS_RAWIO) user inside guest could use this flaw
to crash the Qemu instance resulting in DoS.