dbus-sysdeps-unix.c: In function ‘_dbus_read_credentials_socket’:
dbus-sysdeps-unix.c:2061:9: error: ISO C90 forbids mixed declarations and code [-Werror=declaration-after-statement]
adt_session_data_t *adth = NULL;
^
Signed-off-by: Alan Coopersmith <alan.coopersmith@oracle.com>
Bug: https://bugs.freedesktop.org/show_bug.cgi?id=102145
Reviewed-by: Philip Withnall <withnall@endlessm.com>
Reviewed-by: Simon McVittie <smcv@collabora.com>
Previously, the listen() backlog was set to an arbitrary 30. This means
that if dbus-daemon is overloaded only 30 more connections may be queued
by the kernel, before connect() fails with EAGAIN. (Note that EAGAIN !=
EINPROGRESS -- the latter is what is returned if a connection is queued
and being processed for asynchronous sockets; EAGAIN in this case is
really an error, that cannot be recovered from).
Most software simply sets SOMAXCONN as backlog for AF_UNIX sockets, to
allow queuing of as many connections as the kernel allows. SOMAXCONN is
128 on Linux, which is not particularly high, but at least higher than
30.
This patch changes dbus-daemon to do the same.
I noticed this when flooding dbus-daemon with a lot of connections,
where it pretty quickly ceased to respond, much earlier than it really
should.
Note that the backlog has nothing to do with the number of concurrent
connections allowed, it simply controls how many queued, but not
accept()ed connections there may be on the listening socket.
(cherry picked from commit 12bd6e893c)
Bug: https://bugs.freedesktop.org/show_bug.cgi?id=95264
Bug-Debian: https://bugs.debian.org/872144
Reviewed-by: Simon McVittie <smcv@collabora.com>
Reviewed-by: Thiago Macieira <thiago@kde.org>
By default, Expat uses cryptographic-quality random numbers as a salt for
its hash algorithm, and since 2.2.1 it gets them from the getrandom
syscall on Linux. That syscall refuses to return any entropy until the
kernel's CSPRNG (random pool) has been initialized. Unfortunately, this
can take as long as 40 seconds on embedded devices with few entropy
sources, which is too long: if the system dbus-daemon blocks for that
length of time, important D-Bus clients like systemd and systemd-logind
time out and fail to connect to it.
We're parsing small configuration files here, and we trust them
completely, so we don't need to defend against hash collisions: nobody
is going to be crafting them to cause pathological performance.
Bug: https://bugs.freedesktop.org/show_bug.cgi?id=101858
Signed-off-by: Simon McVittie <smcv@debian.org>
Tested-by: Christopher Hewitt <hewitt@ieee.org>
Reviewed-by: Philip Withnall <withnall@endlessm.com>
configure.ac will detect PYTHON=python3 if there is no python
executable in the PATH.
Bug: https://bugs.freedesktop.org/show_bug.cgi?id=101716
Reviewed-by: Philip Withnall <withnall@endlessm.com>
Signed-off-by: Simon McVittie <smcv@collabora.com>
It is too easy for a developer working in an environment that has a
session bus to write tests that pass locally, but fail in minimal
environments. This is also risky because the tests might do
destructive things on the developer's real session bus. We can avoid
connecting to the session bus by consistently removing its address
from the environment, and replacing it with something that will
always fail.
Signed-off-by: Simon McVittie <smcv@collabora.com>
Reviewed-by: Philip Withnall <withnall@endlessm.com>
Bug: https://bugs.freedesktop.org/show_bug.cgi?id=101698
When we intend to exercise the default behaviour in the absence of
DBUS_SESSION_BUS_ADDRESS (but with an XDG_RUNTIME_DIR present), it would
help if we unset DBUS_SESSION_BUS_ADDRESS. Otherwise we'll just connect
to the real session bus, if there is one.
Signed-off-by: Simon McVittie <smcv@collabora.com>
Reviewed-by: Philip Withnall <withnall@endlessm.com>
Bug: https://bugs.freedesktop.org/show_bug.cgi?id=101698
test-pending-call-disconnected relies on being run under a session bus.
On master, the TESTS in this directory all get that treatment, but
in dbus-1.10 they do not. This caused test-pending-call-disconnected
to fail in minimal environments like travis-ci where there is no
developer-initiated session bus.
Backport part of commit ec6b220 "name-test: run most C tests directly,
not via run-test.sh" to wrap it in dbus-run-session. This is better
than putting it in run-test.sh because this way, its TAP output is
parsed directly by Automake.
It also has the side benefit of exercising dbus-run-session in the
automated tests.
Signed-off-by: Simon McVittie <smcv@collabora.com>
Reviewed-by: Philip Withnall <withnall@endlessm.com>
Bug: https://bugs.freedesktop.org/show_bug.cgi?id=101698
If we run out of memory while calling _dbus_type_writer_recurse()
(which is impossible for most contained types, but can happen for
structs and dict-entries), then the memory we allocated in the call to
_dbus_message_iter_open_signature() will still be allocated, and we
have to free it in order to return to the state of the world prior to
calling open_container().
One might reasonably worry that this change can break callers that use
this (incorrect) pattern:
if (!dbus_message_iter_open_container (outer, ..., inner))
{
dbus_message_iter_abandon_container (outer, inner);
goto fail;
}
/* now we know inner is open, and we must close it later */
However, testing that pattern with _dbus_test_oom_handling()
demonstrates that it already dies with a DBusString assertion failure
even before this commit.
This is all concerningly fragile, and I think the next step should be
to zero out DBusMessageIter instances when they are invalidated, so
that a "double-free" is always detected.
Signed-off-by: Simon McVittie <smcv@collabora.com>
Reviewed-by: Philip Withnall <withnall@endlessm.com>
Bug: https://bugs.freedesktop.org/show_bug.cgi?id=101568
(cherry picked from commit 031aa2ceb3)
Found by source code inspection while trying to debug an unrelated
leak.
Signed-off-by: Simon McVittie <smcv@collabora.com>
Reviewed-by: Philip Withnall <withnall@endlessm.com>
Bug: https://bugs.freedesktop.org/show_bug.cgi?id=101568
(cherry picked from commit 6b7bdb105b)
If we somehow get an autolaunch address with multiple
semicolon-separated components, and one of them fails, then we will
hit an assertion failure when we try the next one.
Signed-off-by: Simon McVittie <smcv@collabora.com>
Reviewed-by: Philip Withnall <withnall@endlessm.com>
Bug: https://bugs.freedesktop.org/show_bug.cgi?id=101257
(cherry picked from commit ecdcb86bff)
The build timestamp is not particularly useful (the version number of
the package is already present in the HTML), and it prevents the build
from being reproducible. See <https://reproducible-builds.org/> for more
information.
Signed-off-by: Simon McVittie <smcv@debian.org>
Reviewed-by: Philip Withnall <withnall@endlessm.com>
Bug: https://bugs.freedesktop.org/show_bug.cgi?id=100692
(cherry picked from commit 0310ead002)
The error message was leaked when blocking on a pending call after
the connection was disconnected.
Reviewed-by: Philip Withnall <withnall@endlessm.com>
[smcv: re-word commit message]
Reviewed-by: Simon McVittie <smcv@collabora.com>
Bug: https://bugs.freedesktop.org/show_bug.cgi?id=101481
git.freedesktop.org no longer offers anonymous checkouts; that facility
moved to anongit.freedesktop.org.
Signed-off-by: Simon McVittie <smcv@collabora.com>
Bug: https://bugs.freedesktop.org/show_bug.cgi?id=100715
One level of pointer indirection too many when passing the arguments to
dbus_message_append_args().
Bug: https://bugs.freedesktop.org/show_bug.cgi?id=100568
Signed-off-by: Philip Withnall <withnall@endlessm.com>
Reviewed-by: Simon McVittie <smcv@collabora.com>
avc_init() in the SELinux code path is creating a new thread, we need to
set to capabilities before it gets created so it has the permission to
send audit messages.
It also make more sense to open the audit netlink before the different
logging callbacks are set.
Bug: https://bugs.freedesktop.org/show_bug.cgi?id=92832
[smcv: add comments explaining why initialization must happen in this
specific order]
Reviewed-by: Simon McVittie <simon.mcvittie@collabora.co.uk>
Bug-Debian: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=857660
Reviewed-by: Stephen Smalley <sds@tycho.nsa.gov>
(cherry picked from commit a3a5935a0a)
Creating a directory is atomic, stat'ing it to see whether to remove
it is very much not.
Bug: https://bugs.freedesktop.org/show_bug.cgi?id=99828
Signed-off-by: Simon McVittie <simon.mcvittie@collabora.co.uk>
Reviewed-by: Philip Withnall <withnall@endlessm.com>
If we don't trap EEXIST and its Windows equivalent, we are unable to
detect the situation where we create an ostensibly unique
subdirectory in a shared /tmp, but an attacker has already created it.
This affects dbus-nonce (the nonce-tcp transport) and the activation
reload test.
Add a new _dbus_ensure_directory() for the one case where we want it to
succeed even on EEXIST: the DBUS_COOKIE_SHA1 keyring, which we know
we are creating in our own trusted "official" $HOME. In the new
transient service support on Bug #99825, ensure_owned_directory()
would need the same treatment.
We are not treating this as a serious security problem, because the
nonce-tcp transport is rarely enabled on Unix and there are multiple
mitigations.
The nonce-tcp transport creates a new unique file with O_EXCL and 0600
(private to user) permissions, then overwrites the requested filename
via atomic-overwrite, so the worst that could happen there is that an
attacker could place a symbolic link matching the name of a directory
we are going to create, causing a dbus-daemon configured for nonce-tcp
to traverse the symlink and atomically overwrite a file named "nonce"
in a directory of the attacker's choice, with new random contents that
are not known to the attacker. This seems unlikely to be exploitable
for anything worse than denial of service in practice. In mainline
Linux since 3.6, this attack is also defeated by the
fs.protected_symlinks sysctl, which many distributions enable by default.
The activation reload test suffers from a classic symlink attack
due to time-of-check/time-of-use errors in its implementation, but as
part of the developer-only "embedded tests" that are only intended
to be run on a trusted machine, it is not treated as security-sensitive.
That code path will be fixed in a subsequent commit.
Bug: https://bugs.freedesktop.org/show_bug.cgi?id=99828
Signed-off-by: Simon McVittie <simon.mcvittie@collabora.co.uk>
Reviewed-by: Philip Withnall <withnall@endlessm.com>
Hopefully this has better uptime than snapshot.debian.org, which is
really an archival service rather than a production component.
This particular autoconf-archive version was in Ubuntu 16.10, so it
should stay around for a while.
Signed-off-by: Simon McVittie <smcv@debian.org>
(cherry picked from commit 9935a5b7d1)
Debian stable, Debian testing and Ubuntu LTS provide a reasonable
spectrum of old and new distributions. I'm only doing one build on
each to avoid a combinatorial explosion of options.
The Docker images don't have any deb-src apt sources set up, so don't
use `apt-get build-dep`; just include dependencies manually.
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=98889
Reviewed-by: Philip Withnall <philip.withnall@collabora.co.uk>
[smcv: move comment to install script as suggested]
Signed-off-by: Simon McVittie <simon.mcvittie@collabora.co.uk>
Bug: https://bugs.freedesktop.org/show_bug.cgi?id=98889
Taken from the version I added to OSTree.
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=98889
set -u forces us to set all variables that we use (for example with the
${foo:=bar} syntax to take an existing value or set a default), or use the
${foo:-bar} syntax to make it explicit that the variable might be unset.
set -o pipefail (which is a bash feature) detects failure in non-last
elements of a pipeline.
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=98889
This aligns it with the more generic script based on this one that
I sent to OSTree.
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=98889
This realigns it with the script loosely based on this one that I
sent to OSTree.
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=98889
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
[smcv: cherry-picked from master to dbus-1.10 to get the Travis-CI setup
consistent between the two branches]
This way the link won't expire in future.
Signed-off-by: Simon McVittie <smcv@debian.org>
[smcv: cherry-picked from master to dbus-1.10 to get the Travis-CI setup
consistent between the two branches; it is not strictly needed on dbus-1.10]