Commit 2782fc51 authored by Lukáš Doktor's avatar Lukáš Doktor Committed by Eduardo Habkost
Browse files

qemu|qtest: Avoid dangerous arguments 



The list object is mutable in python and potentially might modify other
object's arguments when used as default argument. Reproducer:

    >>> vm1 = QEMUMachine("qemu")
    >>> vm2 = QEMUMachine("qemu")
    >>> vm1._wrapper.append("foo")
    >>> print vm2._wrapper
    ['foo']

In this case the `args` is actually copied so it would be safe to keep
it, but it's not a good practice to keep it. The same issue applies in
inherited qtest module.

Signed-off-by: default avatarLukáš Doktor <ldoktor@redhat.com>
Reviewed-by: default avatarEduardo Habkost <ehabkost@redhat.com>
Reviewed-by: default avatarJohn Snow <jsnow@redhat.com>
Message-Id: <20170818142613.32394-3-ldoktor@redhat.com>
Reviewed-by: default avatarCleber Rosa <crosa@redhat.com>
Signed-off-by: default avatarEduardo Habkost <ehabkost@redhat.com>
parent 2d853c70

scripts/qemu.py

+5 −1
Original line number Diff line number Diff line
@@ -30,7 +30,7 @@ class QEMUMachine(object): 
        # vm is guaranteed to be shut down here

    '''



    def __init__(self, binary, args=[], wrapper=[], name=None,

    def __init__(self, binary, args=None, wrapper=None, name=None,

                 test_dir="/var/tmp", monitor_address=None,

                 socket_scm_helper=None, debug=False):

        '''
@@ -46,6 +46,10 @@ class QEMUMachine(object): 
        @param debug: enable debug mode

        @note: Qemu process is not started until launch() is used.

        '''

        if args is None:

            args = []

        if wrapper is None:

            wrapper = []

        if name is None:

            name = "qemu-%d" % os.getpid()

        if monitor_address is None:

scripts/qtest.py

+1 −1
Original line number Diff line number Diff line
@@ -79,7 +79,7 @@ class QEMUQtestProtocol(object): 
class QEMUQtestMachine(qemu.QEMUMachine):

    '''A QEMU VM'''



    def __init__(self, binary, args=[], name=None, test_dir="/var/tmp",

    def __init__(self, binary, args=None, name=None, test_dir="/var/tmp",

                 socket_scm_helper=None):

        if name is None:

            name = "qemu-%d" % os.getpid()