In the linked reproducer, m->fields_size == 0, and we calculate ri == -1, which
of course doesn't end well. Skip the whole calculation if m->fields_size == 0,
and also check that we don't go negative even if it is non-zero.
Fixes https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=19446 and #15583.
This is a security feature, and we thus shouldn't derive the random MACs
from a potentially guessable source. MAC addresses are after all facing
to the outside, and can be interacted with from untrusted environments.
Hence, let's generate them the same way as we generate UUIDs: from
getrandom() or /dev/urandom, and optionally with RDRAND if that's
supported.
RDRAND should be fine, since this is not cryptographic key material, but
ultimately public information. We just want to make sure conflicts are
not likely.
Previously we'd generate the MACs via rand(), which means given the
short seed they are a little bit too guessable, making collisions too
likely. See #14355 in particular.
Fixes: #14355
(Note that #14355 was already fixed by
a0f11d1d11, but I think we should do
better even, and not rely on rand() and uninitialized random pools)
```
21.16. Vendor Class Option
This option is used by a client to identify the vendor that
manufactured the hardware on which the client is running. The
information contained in the data area of this option is contained in
one or more opaque fields that identify details of the hardware
configuration. The format of the Vendor Class option is:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| OPTION_VENDOR_CLASS | option-len |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| enterprise-number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
. .
. vendor-class-data .
. . . . .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 28: Vendor Class Option Format
option-code OPTION_VENDOR_CLASS (16).
option-len 4 + length of vendor-class-data field.
enterprise-number The vendor's registered Enterprise Number as
maintained by IANA [IANA-PEN]. A 4-octet
field containing an unsigned integer.
vendor-class-data The hardware configuration of the node on
which the client is running. A
variable-length field (4 octets less than the
value in the option-len field).
The vendor-class-data field is composed of a series of separate
items, each of which describes some characteristic of the client's
hardware configuration. Examples of vendor-class-data instances
might include the version of the operating system the client is
running or the amount of memory installed on the client.
Each instance of vendor-class-data is formatted as follows:
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-...-+-+-+-+-+-+-+
| vendor-class-len | opaque-data |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-...-+-+-+-+-+-+-+
Figure 29: Format of vendor-class-data Field
The vendor-class-len field is 2 octets long and specifies the length
of the opaque vendor-class-data in network byte order.
Servers and clients MUST NOT include more than one instance of
OPTION_VENDOR_CLASS with the same Enterprise Number. Each instance
of OPTION_VENDOR_CLASS can carry multiple vendor-class-data
instances.
```
Let's make sure we always apply the process properties from the user
record, in all our three successful paths:
1. when we register a regular session
2. when we run for the systemd --user session
3. when we have no logind (but might still have complex user records
from elsewhere) and thus exit early
This variable is read by the module and can be used instead of the
suspend= PAM module parameter.
It is also set for the session itself to make debugging easy.
This adds a new switch try-empty-password. If set and none of PKCS#11 or
key files work, it is attempted to unlock the volume with an empty
password, before the user is asked for a password.
Usecase: an installer generates an OS image on one system, which is the
booted up for the first time in a possibly different system. The image
is encrypted using a random volume key, but an empty password. A tool
that runs on first boot then queries the user for a password to set or
enrols the volume in the TPM, removing the empty password. (Of course, in
such a scenario it is important to never reuse the installer image on
multiple systems as they all will have the same volume key, but that's a
different question.)
Let's make loading of keys a bit more automatic and define a common
place where key files can be placed. Specifically, whenever a volume of
name "foo" is attempted, search for a key file in
/etc/cryptsetup-keys.d/foo.key and /run/cryptsetup-keys.d/foo.key,
unless a key file is declared explicitly.
With this scheme we have a simple discovery in place that should make it
more straightfoward wher to place keys, and requires no explicit
configuration to be used.
This is useful when the key file is acquired dynamically in some form
and should be erased after use.
Note that this code tries to be robust, and removes the key file both on
success and on failure.
That's reduce the number of functions dealing with configuration
parsing/loading and should make the code simpler especially since this function
was used only once.
No functional change.
Most complexity of this patch is due to the fact that some manager settings
(basically the watchdog properties) can be set at runtime and in this case the
runtime values must be retained over daemon-reload or daemon-reexec.
For consistency sake, all watchdog properties behaves now the same way, that
is:
- Values defined by config files can be overridden by writing the new value
through their respective D-BUS properties. In this case, these values are
preserved over reload/reexec until the special value '0' or USEC_INFINITY
is written, which will then restore the last values loaded from the config
files. If the restored value is '0' or 'USEC_INFINITY', the watchdogs will
be disabled and the corresponding device will be closed.
- Reading the properties from a user instance will return the USEC_INFINITY
value as these properties are only meaningful for PID1.
- Writing to one of the watchdog properties of a user instance's will be a
NOP.
Fixes: #15453
It annoyed me for quite a while that running "journalctl --file=…" on a
file that is not readable failed with a "File not found" error instead
of a permission error. Let's fix that.
We make this work by using the GLOB_NOCHECK flag for glob() which means
that files are not accessible will be returned in the array as they are
instead of being filtered away. This then means that our later attemps
to open the files will fail cleanly with a good error message.
Evgeny Vereshchagin