Qemu block drivers for CLOOP, QCOW2 version 2 and various other image formats
are vulnerable to potential memory corruptions, integer/buffer overflows or
crash caused by missing input validations.

An user able to alter the Qemu disk image files loaded by a guest could use
this flaw to crash the Qemu instance resulting in DoS or corrupt QEMU process
memory on the host, which could potentially result in arbitrary code execution
on the host with the privileges of the QEMU process.

Upstream fixes:
---------------
qcow2: Validate active L1 table offset and size
  -> http://git.qemu.org/?p=qemu.git;a=commit;h=2d51c32c4b511db8bb9e58208f1e2c25e4c06c85

qcow2: Validate snapshot table offset/size
  -> http://git.qemu.org/?p=qemu.git;a=commit;h=ce48f2f441ca98885267af6fd636a7cb804ee646

qcow2: Check refcount table size
  -> http://git.qemu.org/?p=qemu.git;a=commit;h=5dab2faddc8eaa1fb1abdbe2f502001fc13a1b21

qcow2: Check backing_file_offset
  -> http://git.qemu.org/?p=qemu.git;a=commit;h=a1b3955c9415b1e767c130a2f59fee6aa28e575b

qcow2: Check header_length
  -> http://git.qemu.org/?p=qemu.git;a=commit;h=24342f2cae47d03911e346fe1e520b00dc2818e0

curl: check data size before memcpy to local buffer
  -> http://git.qemu.org/?p=qemu.git;a=commit;h=6d4b9e55fc625514a38d27cff4b9933f617fa7dc

vdi: add bounds checks for blocks_in_image and disk_size
  -> http://git.qemu.org/?p=qemu.git;a=commit;h=63fa06dc978f3669dbfd9443b33cde9e2a7f4b41

vpc/vhd: add bounds check for max_table_entries
  -> http://git.qemu.org/?p=qemu.git;a=commit;h=97f1c45c6f456572e5b504b8614e4a69e23b8e3a

block/cloop: refuse images with bogus offsets
  -> http://git.qemu.org/?p=qemu.git;a=commit;h=f56b9bc3ae20fc93815b34aa022be919941406ce

block/cloop: refuse images with huge offsets arrays
  -> http://git.qemu.org/?p=qemu.git;a=commit;h=7b103b36d6ef3b11827c203d3a793bf7da50ecd6

block/cloop: validate block_size header field
  -> http://git.qemu.org/?p=qemu.git;a=commit;h=d65f97a82c4ed48374a764c769d4ba1ea9724e97