The scanning to find the end of a positional parameter designator in
GVariant text format (e.g. '%i') is currently broken in case the 'end'
pointer is not specified.
The scan is controlled by a somewhat complicated loop that needs to deal
properly with cases like (123, %(ii)) [where '%(ii)' is to be taken
together, but the final ')' not].
This loop missed the case where a format string passed to
g_variant_new_parsed() ended immediately after such a conversion, with a
nul character. In this case the 'end' pointer is NULL, so the only way
we can find the end is by scanning for nul in the string.
In case of g_variant_new_parsed() [which is what this code was designed
to be used for], the bug is somewhat unlikely in practice: the only way
that a valid text-form GVariant could ever contain a positional
parameter replacement at the end of the string is if this positional
parameter were the only thing being returned. In that case, the user
would likely have opted for a more direct approach.
Unfortunately, this code is also active in the tokenisation phase of
g_variant_parse(), before positional parameters are rejected as invalid
for that case. Anyone who calls this function with a nul-terminated
string (and no end pointer) is vulnerable to a crash from malicious user
input. This can be seen, at the very least with many commandline tools:
$ dconf write /x '%i'
Segmentation fault
We fix this problem by searching for the nul character in this case, in
addition to comparing the end pointer.
This problem is almost certainly limited to being able to cause crashes.
The loop in question only performs reads and, in the security-sensitive
case, the token will be quickly rejected after the loop is finished
(since it starts with '%' and the 'app' pointer is unset). This is
further mitigated by the fact that there are no known cases of GVariant
text format being used as part of a protocol at a privilege barrier.
Some applications support running in a mode where they present
themselves as a different application to the user (for example web
browsers or terminals).
To facilitate this, add an option --gapplication-app-id which allows
users to override an application's id from desktop files or similar.
Applications need to opt-in to this by setting the
G_APPLICATION_CAN_OVERRIDE_APP_ID flag.
https://bugzilla.gnome.org/show_bug.cgi?id=743933
currently schema_list will iterate over the default SchemaSource
list, and not the one associated with the passed in Schema. This
means schema_list can give incorrect results for a Schema fetched
from a non-default SchemaSource, like via new_from_directory.
https://bugzilla.gnome.org/show_bug.cgi?id=757506
Perform conversion before writing a value out of the cache into the registry,
and convert back when reading a value into the cache out of the registry.
The registry holds UTF-8 strings.
This is a flag used to understand if a key exists on the registry
and if it is readable. It makes more sense to rename it as readable
since anyway a key that does not exists anymore is a key that is
not readable.
