This reverts PR #23269 and its follow-up commit. Especially,
2299b1cae3 (partially), and
3cf63830ac.
The PR was merged without final approval, and has several issues:
- The NetLabel for static addresses are not assigned, as labels are
stored in the Address objects managed by Network, instead of Link.
- If NetLabel is specified for a static address, then the address
section will be invalid and the address will not be configured,
- It should be implemented with Request object,
- There is no test about the feature.
Fixes: CID#1469712
CID 1469712 (#1 of 1): Unused value (UNUSED_VALUE)
returned_value: Assigning value from sd_id128_from_string(word + 2, &boot_id) to r here,
but that stored value is overwritten before it can be used.
Not only block subsystem, but also misc has device named "loop*", and
the test always said that the following device is newly found:
---
/* test_sd_device_enumerator_filter_subsystem */
New device found: subsystem:misc syspath:/sys/devices/virtual/misc/loop-control
1 new devices are found in re-scan
---
The lookup "works", but is not useful. It was introduced in
9c66f52813.
And printf will NULL args is invalid was introduced in
5d1ce25728 when support for fds was initally
added :(
New directive `NetLabel=` provides a method for integrating dynamic network
configuration into Linux NetLabel subsystem rules, used by Linux security
modules (LSMs) for network access control. The option expects a whitespace
separated list of NetLabel labels. The labels must conform to lexical
restrictions of LSM labels. When an interface is configured with IP addresses,
the addresses and subnetwork masks will be appended to the NetLabel Fallback
Peer Labeling rules. They will be removed when the interface is
deconfigured. Failures to manage the labels will be ignored.
Example:
```
[DHCP]
NetLabel=system_u:object_r:localnet_peer_t:s0
```
With the above rules for interface `eth0`, when the interface is configured with
an IPv4 address of 10.0.0.0/8, `systemd-networkd` performs the equivalent of
`netlabelctl` operation
```
$ sudo netlabelctl unlbl add interface eth0 address:10.0.0.0/8 label:system_u:object_r:localnet_peer_t:s0
```
Result:
```
$ sudo netlabelctl -p unlbl list
...
interface: eth0
address: 10.0.0.0/8
label: "system_u:object_r:localnet_peer_t:s0"
...
```
We currently have a convoluted and complex selection of which random
numbers to use. We can simplify this down to two functions that cover
all of our use cases:
1) Randomness for crypto: this one needs to wait until the RNG is
initialized. So it uses getrandom(0). If that's not available, it
polls on /dev/random, and then reads from /dev/urandom. This function
returns whether or not it was successful, as before.
2) Randomness for other things: this one uses getrandom(GRND_INSECURE).
If it's not available it uses getrandom(GRND_NONBLOCK). And if that
would block, then it falls back to /dev/urandom. And if /dev/urandom
isn't available, it uses the fallback code. It never fails and
doesn't return a value.
These two cases match all the uses of randomness inside of systemd.
I would prefer to make both of these return void, and get rid of the
fallback code, and simply assert in the incredibly unlikely case that
/dev/urandom doesn't exist. But Luca disagrees, so this commit attempts
to instead keep case (1) returning a return value, which all the callers
already check, and fix the fallback code in (2) to be less bad than
before.
For the less bad fallback code for (2), we now use auxval and some
timestamps, together with various counters representing the invocation,
hash it all together and provide the output. Provided that AT_RANDOM is
secure, this construction is probably okay too, though notably it
doesn't have any forward secrecy. Fortunately, it's only used by
random_bytes() and not by crypto_random_bytes().
Some compiler wrappers like honggfuzz pass -fno-builtin explicitly
and because of that the tests where fabs is used fail to compile
with something like
```
FAILED: test-bus-marshal
...
/usr/bin/ld: test-bus-marshal.p/src_libsystemd_sd-bus_test-bus-marshal.c.o: undefined reference to symbol 'fabs@@GLIBC_2.2.5'
/usr/bin/ld: /usr/lib64/libm.so.6: error adding symbols: DSO missing from command line
collect2: error: ld returned 1 exit status
```
Fun fact: it took honggfuzz less than a minute to discover
https://github.com/advisories/GHSA-gmc7-pqv9-966m used by
systemd to compress/descompress some stuff.
The existing sd_hwdb_new function always initializes the hwdb from the
first successful hwdb.bin it finds from hwdb_bin_paths. This means there
is currently no way to initialize a hwdb from an explicit path, which
would be useful for systemd-hwdb query.
Add sd_hwdb_new_from_path to allow a sd_hwdb to be initialized from a
custom path outside of hwdb_bin_paths.
Include this header to fix errors when including hwdb-internal.h:
../src/libsystemd/sd-hwdb/hwdb-internal.h:16:21: error: field ‘st’ has incomplete type
16 | struct stat st;
3970 e = object_path_startswith(path, prefix);
(gdb) p path
$1 = 0x55c5a166f768 "/org/freedesktop/portable1/image"
(gdb) p prefix
$2 = 0x55c59ffc2928 "/org/freedesktop/portable1/image"
(gdb) p e
$1 = 0x5581a1675788 ""
This can be a bit confusing in certain cases, so add a comment and a
test to make the behaviour clearer and explicit.
Previously, in sd_device_new_from_subsystem_sysname(), '/' in sysname
was replaced '!' for several limited subsystems. This was based on a wrong
assumption that no sysname in e.g. driver subsystem does not contain '!'.
And the assumption is actually wrong, and trigger issue #23327.
In device_set_sysname_and_sysnum() we unconditionally replace '!' in the
filename. Hence, the translation in sd_device_new_from_subsystem_sysname()
must be also done unconditionally.
Fixes#23327.
Without the size limits, oss-fuzz creates huge samples that time out. Usually
this is because some of our code has bad algorithmic complexity. For data like
configuration samples we don't need to care about this: non-rogue configs are
rarely more than a few items, and a bit of a slowdown with a few hundred items
is acceptable. This wouldn't be OK for processing of untrusted data though.
We need to set the limit in two ways: through .options and in the code. The
first because it nicely allows libFuzzer to avoid wasting time, and the second
because fuzzers like hongfuzz and afl don't support .options.
While at it, let's fix an off-by-one (65535 is the largest offset for a
power-of-two size, but we're checking the size here).
Co-authored-by: Zbigniew Jędrzejewski-Szmek <zbyszek@in.waw.pl>
In sd_network_monitor_flush(), we shouldn't remove the inotify
watch for the current directory if the directory the network
monitor is waiting for wasn't created yet.
inotify_add_watch() returns the same unique watch descriptor if a
path is already being watched. Let's return the watch descriptor
from monitor_add_inotify_watch() so we can check if it's the same
as the watch descriptor of the inotify event. If they are equal,
we're still watching the same path and we don't need to remove the
inotify watch just yet.
On several CI environments, it seems that some loop block devices and
corresponding bdi devices are sometimes removed during the test is
running. Let's exclude them.
Fixes#22970.
David Tardon
Yu Watanabe
Shreenidhi Shedi
Luca Boccassi
i-do-cpp
Zbigniew Jędrzejewski-Szmek
Topi Miettinen
Jason A. Donenfeld
Evgeny Vereshchagin
Nick Rosbrook
Daan De Meyer
Mike Gilbert
Lennart Poettering