451672e890
There are three ways to run chronyd:
- start as root, and continue running as root;
- start as root, then setuid() to a non-root user via either a command
line option or a configuration directive;
- start as root, and setuid() to a build-time specified non-root user.
Currently, the first situation is used by Buildroot, which does not
follow security best practices of dropping elevated privileges for
daemon at runtime when that is possible.
We switch to the third situation, where a compile-time default non-root
user is then used at runtime to drop privileges, with libcap used to
keep the capabilities required to call the appropriate syscalls to
adjust the system time (typically, CAP_SYS_TIME to call adjtimex() or
clock_settime() et al.).
This means that libcap is now a mandatory dependency.
To be noted: users who previously had configured their systems to run
chronyd as non root, would have done so with either the command-line
option (`-u`), or the configuration directive (`user`). Those take
precedence over the compile-time default, so this should not break their
systems (presumably, they also run as the `chrony` user). They would
also have taken care to run chronyc as the appropriate user to
manipulate chronyd at runtime via the UNIX socket.
For those who were running chronyd as root, this does not change either:
the functionality is unchanged, and they were running chronyc as root,
which should still be capable of manipulating chronyd via its UNIX
socket.
Take that opportunity to brine chrony's Config.in to current coding
style: enclose sub-option in an if-endif block.
Signed-off-by: James Kent <james.kent@orchestrated-technology.com>
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>
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|---|---|---|
| arch | ||
| board | ||
| boot | ||
| configs | ||
| docs | ||
| fs | ||
| linux | ||
| package | ||
| support | ||
| system | ||
| toolchain | ||
| utils | ||
| .checkpackageignore | ||
| .clang-format | ||
| .defconfig | ||
| .flake8 | ||
| .gitignore | ||
| .gitlab-ci.yml | ||
| .shellcheckrc | ||
| CHANGES | ||
| Config.in | ||
| Config.in.legacy | ||
| COPYING | ||
| DEVELOPERS | ||
| Makefile | ||
| Makefile.legacy | ||
| README | ||
Buildroot is a simple, efficient and easy-to-use tool to generate embedded Linux systems through cross-compilation. The documentation can be found in docs/manual. You can generate a text document with 'make manual-text' and read output/docs/manual/manual.text. Online documentation can be found at http://buildroot.org/docs.html To build and use the buildroot stuff, do the following: 1) run 'make menuconfig' 2) select the target architecture and the packages you wish to compile 3) run 'make' 4) wait while it compiles 5) find the kernel, bootloader, root filesystem, etc. in output/images You do not need to be root to build or run buildroot. Have fun! Buildroot comes with a basic configuration for a number of boards. Run 'make list-defconfigs' to view the list of provided configurations. Please feed suggestions, bug reports, insults, and bribes back to the buildroot mailing list: buildroot@buildroot.org You can also find us on #buildroot on OFTC IRC. If you would like to contribute patches, please read https://buildroot.org/manual.html#submitting-patches