Qemu: block: multiple integer overflow flaws

Multiple integer overflows in the block drivers in QEMU, possibly before 2.0.0, allow local users to cause a denial of service crash via a crafted catalog size in 1 the parallelsopen function in block/parallels.c or 2 bochsopen function in bochs.c, a large L1 table in the 3 qcow2snapshotloadtmp i...