qemu: e1000 driver buffer overflow when processing large packets when SBP and LPE flags are disabled

Buffer overflow in the e1000receive function in the e1000 device driver hw/e1000.c in QEMU 1.3.0-rc2 and other versions, when the SBP and LPE flags are disabled, allows remote attackers to cause a denial of service guest OS crash and possibly execute arbitrary guest code via a large packet...