Some issues can be found only when a fuzzed image has a partial structure,
e.g. has L1/L2 tables but no refcount ones. Generation of an entirely
defined image limits these cases. Now the Image constructor creates only
a header and a backing file name (if any), other image elements are generated
in the 'create_image' API.
Signed-off-by: Maria Kustova <maria.k@catit.be>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Entries in L1/L2 entries are based on a portion of random guest clusters.
L2 entries contain offsets to host image clusters filled with random data.
Clusters for L1/L2 tables and guest data are selected randomly.
Signed-off-by: Maria Kustova <maria.k@catit.be>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
__init__.py provides the public API required by the test runner
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Maria Kustova <maria.k@catit.be>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
The layout submodule of the qcow2 package creates a random valid image,
randomly selects some amount of its fields, fuzzes them and write the fuzzed
image to the file. Fuzzing process can be controlled by an external
configuration.
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Maria Kustova <maria.k@catit.be>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
The fuzz submodule of the qcow2 image generator contains fuzzing functions for
image fields.
Each fuzzing function contains a list of constraints and a call of a helper
function that randomly selects a fuzzed value satisfied to one of constraints.
For now constraints include only known as invalid or potentially dangerous
values. But after investigation of code coverage by fuzz tests they will be
expanded by heuristic values based on inner checks and flows of a program
under test.
Now fuzzing of a header, header extensions and a backing file name is
supported.
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Maria Kustova <maria.k@catit.be>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
