The vulnerability reported as GNOME/glib#3268 can be characterized
as: these signals from an attacker should not be delivered to either
the GDBusConnection or the GDBusProxy, but in fact they are (in at
least some scenarios).
Reproduces: https://gitlab.gnome.org/GNOME/glib/-/issues/3268
Signed-off-by: Simon McVittie <smcv@collabora.com>
The expected result is that because TEST_CONN_SERVICE owns
ALREADY_OWNED_NAME but not (yet) OWNED_LATER_NAME, the signal will be
delivered to the subscriber for the former but not the latter.
Before #3268 was fixed, it was incorrectly delivered to both.
Reproduces: https://gitlab.gnome.org/GNOME/glib/-/issues/3268 (partially)
Signed-off-by: Simon McVittie <smcv@collabora.com>
Otherwise a malicious connection on a shared bus, especially the system
bus, could trick GDBus clients into processing signals sent by the
malicious connection as though they had come from the real owner of a
well-known service name.
Resolves: https://gitlab.gnome.org/GNOME/glib/-/issues/3268
Signed-off-by: Simon McVittie <smcv@collabora.com>
We will use this in a subsequent commit to prevent signals from an
impostor from being delivered to a subscriber.
To avoid message reordering leading to misleading situations, this does
not use the existing mechanism for watching bus name ownership, which
delivers the ownership changes to other main-contexts. Instead, it all
happens on the single thread used by the GDBusWorker, so the order in
which messages are received is the order in which they are processed.
Signed-off-by: Simon McVittie <smcv@collabora.com>
This will become confusing when we start tracking the owner of a
well-known-name sender, and it's redundant anyway. Instead, track the
1 bit of data that we actually need: whether it's a well-known name.
Strictly speaking this too is redundant, because it's syntactically
derivable from the sender, but only via extra string operations.
A subsequent commit will add a data structure to keep track of the
owner of a well-known-name sender, at which point this boolean will
be replaced by the presence or absence of that data structure.
Signed-off-by: Simon McVittie <smcv@collabora.com>
No functional change, just removing some nesting. The check for whether
signal_data->subscribers is empty changes from a conditional that tests
whether it is into an early-return if it isn't.
A subsequent commit will add additional conditions that make us consider
a SignalData to be still in use and therefore not eligible to be removed.
Signed-off-by: Simon McVittie <smcv@collabora.com>
No functional changes, except that the implicit ownership-transfer
for the rule field becomes explicit (the local variable is set to NULL
afterwards).
Signed-off-by: Simon McVittie <smcv@collabora.com>
Subsequent changes will need to access these data structures from
on_worker_message_received(). No functional change here, only moving
code around.
Signed-off-by: Simon McVittie <smcv@collabora.com>
Using these is a bit more clearly correct than repeating them everywhere.
To avoid excessive diffstat in a branch for a bug fix, I'm not
immediately replacing all existing occurrences of the same literals with
these names.
The names of these constants are chosen to be consistent with libdbus,
despite using somewhat outdated terminology (D-Bus now uses the term
"well-known bus name" for what used to be called a service name,
reserving the word "service" to mean specifically the programs that
have .service files and participate in service activation).
Signed-off-by: Simon McVittie <smcv@collabora.com>
On GNOME/glib#3268 there was some concern about whether this would
allow an attacker to send signals and have them be matched to a
GDBusProxy in this situation, but it seems that was a false alarm.
Signed-off-by: Simon McVittie <smcv@collabora.com>
This somewhat duplicates test_connection_signals(), but is easier to
extend to cover different scenarios.
Each scenario is tested three times: once with lower-level
GDBusConnection APIs, once with the higher-level GDBusProxy (which
cannot implement all of the subscription scenarios, so some message
counts are lower), and once with both (to check that delivery of the
same message to multiple destinations is handled appropriately).
Signed-off-by: Simon McVittie <smcv@collabora.com>
Technically we can’t rely on it being kept alive by the `message->body`
pointer, unless we can guarantee that the `GVariant` is always
serialised. That’s not necessarily the case, so keep a separate ref on
the arg0 value at all times.
This avoids a potential use-after-free.
Spotted by Thomas Haller in
https://gitlab.gnome.org/GNOME/glib/-/merge_requests/3720#note_1924707.
[This is a prerequisite for having tests pass after fixing the
vulnerability described in glib#3268, because after fixing that
vulnerability, the use-after-free genuinely does happen during
regression testing. -smcv]
Signed-off-by: Philip Withnall <pwithnall@gnome.org>
Helps: #3183, #3268
(cherry picked from commit 10e9a917be7fb92b6b27837ef7a7f1d0be6095d5)
Release branches older than the current stable release are intended
for long-term-supported OS distributions such as Debian, RHEL or
Ubuntu LTS where GLib is part of the OS itself, and therefore an
OS vendor that wants to minimize regression risk in other OS components
might reasonably prefer to backport high-impact bug fixes instead of
upgrading to new GLib branches.
MSYS2 does not fall into that category: it is an add-on to an operating
system that does not contain GLib as OS functionality (namely, Windows),
making its maintainers less change-averse than LTS distribution vendors,
and in reality it has already upgraded its packaged GLib to 2.80.x.
Making these CI jobs non-blockers ensures that security fix releases
for LTS Linux distributions do not get held back by build failures on
a platform that is no longer interested in the relevant branch.
Signed-off-by: Simon McVittie <smcv@debian.org>
PCRE2 10.43 has now introduced support for variable-length lookbehind,
so these tests now fail if GLib is built against PCRE2 10.43 or higher.
See
e8db6fa713/ChangeLog (L94).
Rather than making the tests conditional on the version of PCRE2 in use,
just remove them. They are mostly testing the PCRE2 code rather than
any code in GLib, so don’t have much value.
This should fix CI runs on msys2-mingw32, which updated to PCRE2 10.43 2
days ago.
Signed-off-by: Philip Withnall <pwithnall@gnome.org>
The `g_content_type_guess_for_tree` function segfaults currently when
processing filenames that are not valid unicode strings. Let's use the
`g_filename_to_utf8` and `g_utf8_make_valid` functions before other
processing to prevent that.
Fixes: https://gitlab.gnome.org/GNOME/glib/-/issues/3168
(cherry picked from commit 41af42717531a2af6dfd7a4f7b5c5fc228e85f0d)
For the same reasons as in commit 71061fdcb33b8c26f5f8467c, but in this
case we can’t downgrade the version of Meson on the CI runner, so just
tell it to shut up instead.
Signed-off-by: Philip Withnall <pwithnall@gnome.org>
Symptom:
20 0x00007ffff756337b in gtk_widget_size_allocate_with_baseline (widget=0xd7a0c0 [DirectWindow], allocation=, baseline=) at
gdb.error: value has been optimized out
This is just the result of running `black $(git ls-files '*.py')`.
For some reason, the `sh-and-py-check` CI job didn’t run on merge
request !3751, so this non-standard formatting slipped through onto
`main`.
See https://gitlab.gnome.org/GNOME/glib/-/merge_requests/3754#note_1939914
Signed-off-by: Philip Withnall <pwithnall@gnome.org>
This fixes a stack overflow reported by a user who had both the
definition of text/javascript from shared-mime-info 2.3 and the
definition of text/javascript from shared-mime-info 2.4 installed at the
same time. In 2.3, text/javascript is a subtype of
application/ecmascript, but in 2.4 application/ecmascript is a subtype
of text/javascript. Having both at the same time resulted in circular
inheritance.
The new logic keeps a list of all parents that have already been
checked, which is more comprehensive than the old workaround that was
implemented in commit 38869ece2 ("xdgmime: Prevent infinite loops from
badly-formed MIME registrations").
https://bugs.archlinux.org/task/80279
Depending on the operating system, /bin/sh might either be bash (for
example on Fedora or Arch) or dash (for example on Debian or Ubuntu)
or some other POSIX shell.
When bash is asked to run a simple command with no shell keywords or
metacharacters, like this one, it replaces itself with the program
via execve(), but dash does not have that optimization and treats it
like any other program invocation in a larger script: it will fork,
exec the program in the child, and wait for the child in the parent.
This seems like it conflicts with sleep_and_kill() assuming that it can
use the subprocess's process ID as the sleep(1) process ID. Specifically,
if it sends SIGKILL, it will go to the sh(1) process and not the sleep(1)
child, which could result in the sh(1) process being terminated and
its sleep(1) child being leaked.
To get the bash-like behaviour portably, explicitly use the exec builtin
to instruct the shell to replace itself with sleep(1), so that the
process ID previously used for the shell becomes the process ID of the
sleep process.
This appears to resolve an intermittent hang and test timeout on Debian
machines (especially slower ones), although I'm not 100% clear on the
mechanics of how it happens.
Resolves: https://gitlab.gnome.org/GNOME/glib/-/issues/3157
Signed-off-by: Simon McVittie <smcv@collabora.com>
