Without changing the SELinux label for private /dev of a service, it will take
a generic file system label:
system_u:object_r:tmpfs_t:s0
After this change it is the same as without `PrivateDevices=yes`:
system_u:object_r:device_t:s0
This helps writing SELinux policies, as the same rules for `/dev` will apply
despite any `PrivateDevices=yes` setting.
Without changing the SELinux label for private /dev of a service, it will take
a generic file system label:
system_u:object_r:tmpfs_t:s0
After this change it is the same as without `PrivateDevices=yes`:
system_u:object_r:device_t:s0
This helps writing SELinux policies, as the same rules for `/dev` will apply
despite any `PrivateDevices=yes` setting.
This part of the copyright blurb stems from the GPL use recommendations:
https://www.gnu.org/licenses/gpl-howto.en.html
The concept appears to originate in times where version control was per
file, instead of per tree, and was a way to glue the files together.
Ultimately, we nowadays don't live in that world anymore, and this
information is entirely useless anyway, as people are very welcome to
copy these files into any projects they like, and they shouldn't have to
change bits that are part of our copyright header for that.
hence, let's just get rid of this old cruft, and shorten our codebase a
bit.
Files which are installed as-is (any .service and other unit files, .conf
files, .policy files, etc), are left as is. My assumption is that SPDX
identifiers are not yet that well known, so it's better to retain the
extended header to avoid any doubt.
I also kept any copyright lines. We can probably remove them, but it'd nice to
obtain explicit acks from all involved authors before doing that.
This reworks the SELinux and SMACK label fixing calls in a number of
ways:
1. The two separate boolean arguments of these functions are converted
into a flags type LabelFixFlags.
2. The operations are now implemented based on O_PATH. This should
resolve TTOCTTOU races between determining the label for the file
system object and applying it, as it it allows to pin the object
while we are operating on it.
3. When changing a label fails we'll query the label previously set, and
if matches what we want to set anyway we'll suppress the error.
Also, all calls to label_fix() are now (void)ified, when we ignore the
return values.
Fixes: #8566
systemd-sysusers.service unit creates system users and groups and it
could update /etc/passwd, /etc/group, /etc/shadow and /etc/gshadow.
Those files should have '_' smack label because of accessibility.
However, if systemd has its own smack label using '--with-smack-run-label'
configuration, systemd-sysusers process spawned by systemd(pid:1) has
its parent smack label and eventually updated files also is set as its
parent smack label.
This patch fixes that bug by labeling updated files as '_' smack label
when --with-smack-run-label' is enabled.
- Add smack xattr lookup table
- Unify all of mac_smack_apply_xxx{_fd}() to mac_smack_apply() and
mac_smack_apply_fd().
- Add smack xattr read apis similar with apply apis as
mac_smack_read{_fd}().
