diff --git a/man/run0.xml b/man/run0.xml index 1eb9905b57..6f3f959b10 100644 --- a/man/run0.xml +++ b/man/run0.xml @@ -65,6 +65,10 @@ run0 is a symbolic link to systemd-run executable file, and it behaves as run0 if it is invoked through the symbolic link, otherwise behaves as systemd-run. + + Note that TTY isolation as provided by the default value of the option is a + core feature of run0. Redirecting terminals must therefore be done with care, + avoiding giving such control to untrusted programs. @@ -267,6 +271,9 @@ is specified in which case is selected), otherwise the relevant file descriptors are passed through directly. + As mentioned above, TTY isolation as implemented by the default value of this option is + crucial for security, so care must be taken when overriding it. + and were added in v257. was added in v258. diff --git a/man/systemd-mountfsd.service.xml b/man/systemd-mountfsd.service.xml index 2e623a2728..a42c71bdea 100644 --- a/man/systemd-mountfsd.service.xml +++ b/man/systemd-mountfsd.service.xml @@ -46,7 +46,10 @@ If the disk image contains a Verity enabled disk image, along with a signature partition with a key in the kernel keyring or in /etc/verity.d/*.crt (and related - directories) the disk image is considered trusted. + directories) the disk image is considered trusted. Note that the GPT partition table of the disk image + is parsed by the kernel to discover its contents and systemd-mountfsd assumes that + the GPT parser is robust against malformed input and applies no security policies or checks around it. + This service provides one Varlink service: diff --git a/man/systemd-nsresourced.service.xml b/man/systemd-nsresourced.service.xml index e3ac1eb0c3..3c662d04ed 100644 --- a/man/systemd-nsresourced.service.xml +++ b/man/systemd-nsresourced.service.xml @@ -92,6 +92,11 @@ This service provides one Varlink service: io.systemd.NamespaceResource allows registering user namespaces, and assign mounts, cgroups and network interfaces to it. + + Note that combining usage of systemd-nsresourced and systems based on + /etc/subuid and /etc/subgid might result in undefined + behavior if UID or GID ranges defined in those files overlap with the UID or GID ranges used by + nsresourced (the foreign UID range). diff --git a/man/systemd-system.conf.xml b/man/systemd-system.conf.xml index 9f70dc0c3a..9351c6ec52 100644 --- a/man/systemd-system.conf.xml +++ b/man/systemd-system.conf.xml @@ -560,7 +560,10 @@ layer may still control a binary's ownership and setuid bits. Multi-device filesystems such as btrfs are unsupported. - Note that, without further measures to secure the system, kexec can be used to circumvent this. + Note that, without further measures to secure the system, kexec can be used to circumvent + this. Writable and executable memory mappings can also be used to circumvent this, so they need to + be blocked, which can be achieved using other LSMs, or on a per-service basis by using the + MemoryDenyWriteExecute= setting. This requires the kernel to be booted with dm_verity.require_signatures=1 on the kernel command line and with BPF LSM enabled (lsm=...,bpf). If either