Because the recipient process is not yet available, we have to make some
assumption about its AppArmor profile. Parsing the first word of
the Exec value and then chasing symlinks seems like too much magic,
so I've gone for something more explicit. If the .service file contains
AssumedAppArmorLabel=/foo/bar
then we will do the AppArmor query on the assumption that the recipient
AppArmor label will be as stated. Otherwise, we will do a query
with an unspecified label, which means that AppArmor rules that do
specify a peer label will never match it.
Regardless of the result of this query, we will do an independent
AppArmor query when the activation has actually happened, this time
with the correct peer label; that second query will still be used
to decide whether to deliver the message. As a result, if this change
has any effect, it is to make the bus more restrictive; it does not
allow anything that would previously have been denied.
Signed-off-by: Simon McVittie <simon.mcvittie@collabora.co.uk>
Reviewed-by: Philip Withnall <philip.withnall@collabora.co.uk>
Bug: https://bugs.freedesktop.org/show_bug.cgi?id=98666
We specifically do not check recipient policies, because
the recipient policy is based on properties of the
recipient process (in particular, its uid), which we do
not necessarily know until we have already started it.
In this initial implementation we do not check LSMs either,
because we cannot know what LSM context the recipient process
is going to have. However, LSM support will need to be added
to make this feature useful, because StartServiceByName is
normally allowed in non-LSM environments, and is more
powerful than auto-activation anyway.
The StartServiceByName method does not go through this check,
because if access to that method has been granted, then
it's somewhat obvious that you can start arbitrary services.
Signed-off-by: Simon McVittie <simon.mcvittie@collabora.co.uk>
Reviewed-by: Philip Withnall <philip.withnall@collabora.co.uk>
Bug: https://bugs.freedesktop.org/show_bug.cgi?id=98666
This avoids installing the build-dependencies for dbus and its tests,
then uninstalling them all because they rely on libraries whose versions
are older than the ones needed by wine:i386 (and apparently apt prefers
to remove those libraries rather than upgrade them). Doing it this way
round seems to convince apt to do the right thing.
Signed-off-by: Simon McVittie <simon.mcvittie@collabora.co.uk>
Clarify its intended behaviour in two situations:
• For interfaces which have no properties.
• Where some properties are not visible to the caller (due to access
control, for example).
The intention here is for this behaviour to be mandatory, but given that
this is quite late on in the specification’s life, and various D-Bus
libraries like dbus-glib and telepathy-glib cannot support access
control at a per-property level, for example. GDBus can, although it’s
questionable whether this is a good idea. Deliberately leave the
specification open to allow access control at a higher level as well
(such as per-(object, interface)).
Bug: https://bugs.freedesktop.org/show_bug.cgi?id=36190
Reviewed-by: Simon McVittie <simon.mcvittie@collabora.co.uk>
Using versioned names here reinforces the advice given in
<https://dbus.freedesktop.org/doc/dbus-api-design.html#api-versioning>.
I haven't added versions to the sample parameters "com.example.tea" and
"com.example.cappuccino" for methods that query information about
names, on the basis that I assume they are more likely to be intended
to represent an implementation than an API.
Signed-off-by: Simon McVittie <simon.mcvittie@collabora.co.uk>
Reviewed-by: Philip Withnall <philip.withnall@collabora.co.uk>
Bug: https://bugs.freedesktop.org/show_bug.cgi?id=98671
We didn't say that SystemdService existed. Now we do, together with
enough context to make it make sense.
Signed-off-by: Simon McVittie <simon.mcvittie@collabora.co.uk>
Reviewed-by: Philip Withnall <philip.withnall@collabora.co.uk>
Bug: https://bugs.freedesktop.org/show_bug.cgi?id=98671
For something we recommend, that is important enough to have its own
header flag, it doesn't have very good documentation. Redo the text
to suggest that auto-starting is the normal thing and
StartServiceByName is the oddity. That's usually a good principle
to follow, since it dodges time-of-check/time-of-use issues, and the
method call that you presumably wanted to do needs to handle errors
anyway.
Signed-off-by: Simon McVittie <simon.mcvittie@collabora.co.uk>
Reviewed-by: Philip Withnall <philip.withnall@collabora.co.uk>
Bug: https://bugs.freedesktop.org/show_bug.cgi?id=98671
The spec previously mentioned that CORBA calls this activation, but
did not explicitly say that D-Bus has copied this jargon term.
It's 2016, and developers are probably more likely to be familiar
with D-Bus than with CORBA at this point: explicitly say that *our*
jargon term for this action is activation.
Signed-off-by: Simon McVittie <simon.mcvittie@collabora.co.uk>
Reviewed-by: Philip Withnall <philip.withnall@collabora.co.uk>
Bug: https://bugs.freedesktop.org/show_bug.cgi?id=98671
This is a workaround for
<https://bugs.freedesktop.org/show_bug.cgi?id=95263>. If a service
sends a file descriptor sufficiently frequently that its queue of
messages never goes down to 0 fds pending, then it will eventually be
disconnected. logind is one such service.
We do not currently have a good solution for this: the proposed
patches either don't work, or reintroduce a denial of service
security vulnerability (CVE-2014-3637). Neither seems desirable.
However, we can avoid the worst symptoms by trusting uid 0 not to be
malicious.
Bug: https://bugs.freedesktop.org/show_bug.cgi?id=95263
Bug-Ubuntu: https://bugs.launchpad.net/ubuntu/+source/systemd/+bug/1591411
Reviewed-by: Łukasz Zemczak
Tested-by: Ivan Kozik
Tested-by: Finn Herpich
Tested-by: autostatic
Tested-by: Ben Parafina
Signed-off-by: Simon McVittie <simon.mcvittie@collabora.co.uk>
I'm assuming here that any version of clang will be new enough to
understand gcc 2.4 features, which seems rather safe.
Signed-off-by: Simon McVittie <simon.mcvittie@collabora.co.uk>
This is not a security vulnerability because it's test code that
should never be compiled in production.
Signed-off-by: Simon McVittie <simon.mcvittie@collabora.co.uk>
Since early 2015, a DBusSocket has been a struct containing either
an int or a pointer-sized Windows SOCKET. Print them with
"%" DBUS_SOCKET_FORMAT and _dbus_socket_printable().
Bug found by adding more _DBUS_GNUC_PRINTF attributes.
Signed-off-by: Simon McVittie <simon.mcvittie@collabora.co.uk>
This was not a security vulnerability because
_dbus_validity_to_error_message() doesn't return anything containing
"%", but the compiler can't know that.
Found by adding more _DBUS_GNUC_PRINTF attributes.
Signed-off-by: Simon McVittie <simon.mcvittie@collabora.co.uk>
The autoconf macros AX_COMPILER_FLAGS_{CFLAGS|CXXFLAGS|LDFLAGS} test
for compiler and linker support of various flags, and add the flags to
the generated output.
If the command-line option '--enable-compile-warnings' is specified to
'configure', a number of additional warning options is also added to the
output. This is the default.
The AX_COMPILER_FLAGS_* macros add stricter warnings then before. The
patch disables some of them to make dbus build without errors. A later
patch set should fix the warnings and remove the compiler flags.
This patch integrates all tests for compiler flags into the call to
AX_COMPILER_FLAGS_CFLAGS. All tests for compiler flags are now done
in a single place. The old macros have been removed.
Signed-off-by: Thomas Zimmermann <tdz@users.sourceforge.net>
[smcv: add missing $ to DISABLE_WARNINGS]
[smcv: drop -Wno-discarded-qualifiers]
[smcv: drop non-C++ option -Wpointer-sign in C++ mode]
[smcv: work around an AX_COMPILER_FLAGS_CFLAGS bug]
[smcv: this source tree is called dbus, not DBus]
Signed-off-by: Simon McVittie <smcv@debian.org>
Bug: https://bugs.freedesktop.org/show_bug.cgi?id=97357
When reviewing this commit, I said
Looks OK, although this is going to become impossible if we start
using the externally-curated list of warnings from
<https://www.gnu.org/software/autoconf-archive/ax_compiler_flags.html>,
which I've been quite tempted to do.
That time has now come. I think it's more valuable to have comprehensive
warnings under our primary build system, Autotools, than to have
some fairly elaborate CMake scripting to pick up the same compiler
warnings in both build systems; the CMake build system is primarily
there to give us the ability to compile with MSVC, which has orthogonal
compiler warning options anyway.
This reverts commit 41427560af.
Signed-off-by: Simon McVittie <smcv@debian.org>
Acked-by: Ralf Habacker <ralf.habacker@freenet.de>
Bug: https://bugs.freedesktop.org/show_bug.cgi?id=97357
Vaguely based on a patch from Thomas Zimmermann, but with a different
solution to RECURSIVE_MARSHAL_WRITE_TRACE, and additionally fixing
a build failure that only occurs when targeting Unix without libsystemd,
and another that occurs when targeting Windows.
Signed-off-by: Simon McVittie <simon.mcvittie@collabora.co.uk>
Reviewed-by: Thomas Zimmermann <tdz@users.sourceforge.net>
Bug: https://bugs.freedesktop.org/show_bug.cgi?id=97357
Annoyingly, the POSIX way to declare environ (as
"extern char **environ") is a redundant declaration in glibc with
_GNU_SOURCE; work around that.
We also have a workaround for _NSGetEnviron() needing to be used
instead of direct access to environ in at least some circumstances on
Mac OS. Attempt to sync that up between all the files that use environ,
consistently sorting the most special special-cases first (Windows
for files that are compiled there, then Mac, then GNU, with
lowest-common-denominator POSIX last).
The affected files are already OS-specific, so I'm not bothering to
introduce a nicer or higher-level API for this.
Based on the best bits of an earlier patch from me, and an earlier
patch from Thomas Zimmermann.
Signed-off-by: Simon McVittie <simon.mcvittie@collabora.co.uk>
Reviewed-by: Thomas Zimmermann <tdz@users.sourceforge.net>
Bug: https://bugs.freedesktop.org/show_bug.cgi?id=97357
We can avoid duplicating the format string between translation units,
without the compiler warning us that it can't check non-literal
format strings for format-string security vulnerabilities based on %p,
by breaking out the "assertion failed" case into a slow-path.
Signed-off-by: Simon McVittie <simon.mcvittie@collabora.co.uk>
Reviewed-by: Thomas Zimmermann <tdz@users.sourceforge.net>
Bug: https://bugs.freedesktop.org/show_bug.cgi?id=97357
glibc >= 2.24 marks readdir_r() as deprecated. It is meant to be a
thread-safe version of readdir(), but modern implementations of readdir()
are thread-safe anyway (when called with a distinct DIR * argument),
and readdir_r() has some design issues involving PATH_MAX.
This code path is in Linux-specific code, so we can safely assume a
high-quality implementation of readdir().
Signed-off-by: Simon McVittie <smcv@debian.org>
Reviewed-by: Thomas Zimmermann <tdz@users.sourceforge.net>
Bug: https://bugs.freedesktop.org/show_bug.cgi?id=97357
As a general design principle, strings that we aren't going to modify
should usually be const. When compiling with -Wwrite-strings, quoted
string constants are of type "const char *", causing compiler warnings
when they are assigned to char * variables.
Unfortunately, we need to add casts in a few places:
* _dbus_list_append(), _dbus_test_oom_handling() and similar generic
"user-data" APIs take a void *, not a const void *, so we have
to cast
* For historical reasons the execve() family of functions take a
(char * const *), i.e. a constant pointer to an array of mutable
strings, so again we have to cast
* _dbus_spawn_async_with_babysitter similarly takes a char **,
although we can make it a little more const-correct by making it
take (char * const *) like execve() does
This also incorporates a subsequent patch by Thomas Zimmermann to
put various string constants in static storage, which is a little
more efficient.
Signed-off-by: Simon McVittie <smcv@debian.org>
Reviewed-by: Thomas Zimmermann <tdz@users.sourceforge.net>
Bug: https://bugs.freedesktop.org/show_bug.cgi?id=97357
This avoids confusion with the meaning of "release" used by
AX_IS_RELEASE. AX_IS_RELEASE is about facts about the source tree,
namely the distinction between releases (tags) and random snapshots.
The build variants in .travis.yml are about facts about the build
being done, namely the distinction between production and
debug/developer builds.
Production builds are sometimes referred to as "release builds",
for example in typical CMake and MSVC build environments, but a
different term seems better here.
Signed-off-by: Simon McVittie <smcv@debian.org>
Bug: https://bugs.freedesktop.org/show_bug.cgi?id=97357
This patch fixes warnings from '-Wsuggest-attribute=noreturn'. We cannot
enable it unconditionally as it would break libtool.
Signed-off-by: Thomas Zimmermann <tdz@users.sourceforge.net>
Signed-off-by: Thomas Zimmermann <tdz@users.sourceforge.net>
[smcv: omit the part involving environ, which was more involved]
Reviewed-by: Simon McVittie <simon.mcvittie@collabora.co.uk>
Bug: https://bugs.freedesktop.org/show_bug.cgi?id=97357
