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| -rw-r--r-- | changelog.d/9803.doc | 1 | ||||
| -rw-r--r-- | contrib/systemd/override-hardened.conf | 71 | ||||
| -rw-r--r-- | docs/systemd-with-workers/README.md | 30 |
3 files changed, 102 insertions, 0 deletions
diff --git a/changelog.d/9803.doc b/changelog.d/9803.doc new file mode 100644 index 0000000000..16c7ba7033 --- /dev/null +++ b/changelog.d/9803.doc @@ -0,0 +1 @@ +Add hardened systemd files as proposed in [#9760](https://github.com/matrix-org/synapse/issues/9760) and added them to `contrib/`. Change the docs to reflect the presence of these files. diff --git a/contrib/systemd/override-hardened.conf b/contrib/systemd/override-hardened.conf new file mode 100644 index 0000000000..b2fa3ae7c5 --- /dev/null +++ b/contrib/systemd/override-hardened.conf @@ -0,0 +1,71 @@ +[Service] +# The following directives give the synapse service R/W access to: +# - /run/matrix-synapse +# - /var/lib/matrix-synapse +# - /var/log/matrix-synapse + +RuntimeDirectory=matrix-synapse +StateDirectory=matrix-synapse +LogsDirectory=matrix-synapse + +###################### +## Security Sandbox ## +###################### + +# Make sure that the service has its own unshared tmpfs at /tmp and that it +# cannot see or change any real devices +PrivateTmp=true +PrivateDevices=true + +# We give no capabilities to a service by default +CapabilityBoundingSet= +AmbientCapabilities= + +# Protect the following from modification: +# - The entire filesystem +# - sysctl settings and loaded kernel modules +# - No modifications allowed to Control Groups +# - Hostname +# - System Clock +ProtectSystem=strict +ProtectKernelTunables=true +ProtectKernelModules=true +ProtectControlGroups=true +ProtectClock=true +ProtectHostname=true + +# Prevent access to the following: +# - /home directory +# - Kernel logs +ProtectHome=tmpfs +ProtectKernelLogs=true + +# Make sure that the process can only see PIDs and process details of itself, +# and the second option disables seeing details of things like system load and +# I/O etc +ProtectProc=invisible +ProcSubset=pid + +# While not needed, we set these options explicitly +# - This process has been given access to the host network +# - It can also communicate with any IP Address +PrivateNetwork=false +RestrictAddressFamilies=AF_INET AF_INET6 AF_UNIX +IPAddressAllow=any + +# Restrict system calls to a sane bunch +SystemCallArchitectures=native +SystemCallFilter=@system-service +SystemCallFilter=~@privileged @resources @obsolete + +# Misc restrictions +# - Since the process is a python process it needs to be able to write and +# execute memory regions, so we set MemoryDenyWriteExecute to false +RestrictSUIDSGID=true +RemoveIPC=true +NoNewPrivileges=true +RestrictRealtime=true +RestrictNamespaces=true +LockPersonality=true +PrivateUsers=true +MemoryDenyWriteExecute=false diff --git a/docs/systemd-with-workers/README.md b/docs/systemd-with-workers/README.md index cfa36be7b4..a1135e9ed5 100644 --- a/docs/systemd-with-workers/README.md +++ b/docs/systemd-with-workers/README.md @@ -65,3 +65,33 @@ systemctl restart matrix-synapse-worker@federation_reader.service systemctl enable matrix-synapse-worker@federation_writer.service systemctl restart matrix-synapse.target ``` + +## Hardening + +**Optional:** If further hardening is desired, the file +`override-hardened.conf` may be copied from +`contrib/systemd/override-hardened.conf` in this repository to the location +`/etc/systemd/system/matrix-synapse.service.d/override-hardened.conf` (the +directory may have to be created). It enables certain sandboxing features in +systemd to further secure the synapse service. You may read the comments to +understand what the override file is doing. The same file will need to be copied +to +`/etc/systemd/system/matrix-synapse-worker@.service.d/override-hardened-worker.conf` +(this directory may also have to be created) in order to apply the same +hardening options to any worker processes. + +Once these files have been copied to their appropriate locations, simply reload +systemd's manager config files and restart all Synapse services to apply the hardening options. They will automatically +be applied at every restart as long as the override files are present at the +specified locations. + +```sh +systemctl daemon-reload + +# Restart services +systemctl restart matrix-synapse.target +``` + +In order to see their effect, you may run `systemd-analyze security +matrix-synapse.service` before and after applying the hardening options to see +the changes being applied at a glance. |