This implements {createTTY, detach} and all of the combinations and
negations of the two that were previously implemented. There are some
valid questions about out-of-OCI-scope topics like !createTTY and how
things should be handled (why do we dup the current stdio to the
process, and how is that not a security issue). However, these will be
dealt with in a separate patchset.
In order to allow for late console setup, split setupRootfs into the
"preparation" section where all of the mounts are created and the
"finalize" section where we pivot_root and set things as ro. In between
the two we can set up all of the console mountpoints and symlinks we
need.
We use two-stage synchronisation to ensures that when the syscalls are
reordered in a suboptimal way, an out-of-place read() on the parentPipe
will not gobble the ancilliary information.
This patch is part of the console rewrite patchset.
Signed-off-by: Aleksa Sarai <asarai@suse.de>
For example, the /sys/firmware directory should be masked because it can contain some sensitive files:
- /sys/firmware/acpi/tables/{SLIC,MSDM}: Windows license information:
- /sys/firmware/ibft/target0/chap-secret: iSCSI CHAP secret
Signed-off-by: Akihiro Suda <suda.akihiro@lab.ntt.co.jp>
This avoid the goimports tool from remove the libcontainer/keys import line due the package name is diferent from folder name
Signed-off-by: Guilherme Rezende <guilhermebr@gmail.com>
This removes the use of a signal handler and SIGCONT to signal the init
process to exec the users process.
Signed-off-by: Michael Crosby <crosbymichael@gmail.com>
This adds an `--no-new-keyring` flag to run and create so that a new
session keyring is not created for the container and the calling
processes keyring is inherited.
Fixes#818
Signed-off-by: Michael Crosby <crosbymichael@gmail.com>
See https://github.com/docker/docker/issues/22252
Previously we would apply seccomp rules before applying
capabilities, because it requires CAP_SYS_ADMIN. This
however means that a seccomp profile needs to allow
operations such as setcap() and setuid() which you
might reasonably want to disallow.
If prctl(PR_SET_NO_NEW_PRIVS) has been applied however
setting a seccomp filter is an unprivileged operation.
Therefore if this has been set, apply the seccomp
filter as late as possible, after capabilities have
been dropped and the uid set.
Note a small number of syscalls will take place
after the filter is applied, such as `futex`,
`stat` and `execve`, so these still need to be allowed
in addition to any the program itself needs.
Signed-off-by: Justin Cormack <justin.cormack@docker.com>
Fixes#680
This changes setupRlimit to use the Prlimit syscall (rather than
Setrlimit) and moves the call to the parent process. This is necessary
because Setrlimit would affect the libcontainer consumer if called in
the parent, and would fail if called from the child if the
child process is in a user namespace and the requested rlimit is higher
than that in the parent.
Signed-off-by: Julian Friedman <julz.friedman@uk.ibm.com>
This updates runc and libcontainer to handle rlimits per process and set
them correctly for the container.
Signed-off-by: Michael Crosby <crosbymichael@gmail.com>
The re-work of namespace entering lost the setuid/setgid that was part
of the Go-routine based process exec in the prior code. A side issue was
found with setting oom_score_adj before execve() in a userns that is
also solved here.
Docker-DCO-1.1-Signed-off-by: Phil Estes <estesp@linux.vnet.ibm.com> (github: estesp)
This commit adds support to libcontainer to allow caps, no new privs,
apparmor, and selinux process label to the process struct so that it can
be used together of override the base settings on the container config
per individual process.
Signed-off-by: Michael Crosby <crosbymichael@gmail.com>
An init process can join other namespaces (pidns, ipc etc.). This leverages
C code defined in nsenter package to spawn a process with correct namespaces
and clone if necessary.
This moves all setns and cloneflags related code to nsenter layer, which mean
that we dont use Go os/exec to create process with cloneflags and set
uid/gid_map or setgroups anymore. The necessary data is passed from Go to C
using a netlink binary-encoding format.
With this change, setns and init processes are almost the same, which brings
some opportunity for refactoring.
Signed-off-by: Daniel, Dao Quang Minh <dqminh89@gmail.com>
[mickael.laventure@docker.com: adapted to apply on master @ d97d5e]
Signed-off-by: Kenfe-Mickael Laventure <mickael.laventure@docker.com>
Create a unique session key name for every container. Use the pattern
_ses.<postfix> with postfix being the container's Id.
This patch does not prevent containers from joining each other's session
keyring.
Signed-off-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
Today mounts in pre-start hooks get overriden by the default mounts.
Moving the pre-start hooks to after the container mounts and before
the pivot/move root gives better flexiblity in the hooks.
Signed-off-by: Mrunal Patel <mrunalp@gmail.com>
Create a new session key ring '_ses' for every container. This avoids sharing
the key structure with the process that created the container and the
container inherits from.
This patch fixes it init and exec.
Signed-off-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
Due to the fact that the init is implemented in Go (which seemingly
randomly spawns new processes and loves eating memory), most cgroup
configurations are required to have an arbitrary minimum dictated by the
init. This confuses users and makes configuration more annoying than it
should. An example of this is pids.max, where Go spawns multiple
processes that then cause init to violate the pids cgroup constraint
before the container can even start.
Solve this problem by setting the cgroup configurations as late as
possible, to avoid hitting as many of the resources hogged by the Go
init as possible. This has to be done before seccomp rules are applied,
as the parent and child must synchronise in order for the parent to
correctly set the configurations (and writes might be blocked by seccomp).
Signed-off-by: Aleksa Sarai <asarai@suse.com>
Due to the fact that the init is implemented in Go (which seemingly
randomly spawns new processes and loves eating memory), most cgroup
configurations are required to have an arbitrary minimum dictated by the
init. This confuses users and makes configuration more annoying than it
should. An example of this is pids.max, where Go spawns multiple
processes that then cause init to violate the pids cgroup constraint
before the container can even start.
Solve this problem by setting the cgroup configurations as late as
possible, to avoid hitting as many of the resources hogged by the Go
init as possible. This has to be done before seccomp rules are applied,
as the parent and child must synchronise in order for the parent to
correctly set the configurations (and writes might be blocked by seccomp).
Signed-off-by: Aleksa Sarai <asarai@suse.com>
This removes the existing, native Go seccomp filter generation and replaces it
with Libseccomp. Libseccomp is a C library which provides architecture
independent generation of Seccomp filters for the Linux kernel.
This adds a dependency on v2.2.1 or above of Libseccomp.
Signed-off-by: Matthew Heon <mheon@redhat.com>
Aleksa Sarai
Daniel Dao
Akihiro Suda
Guilherme Rezende
Mrunal Patel
Peng Gao
Michael Crosby
Justin Cormack
Julian Friedman
Phil Estes
Stefan Berger
Mrunal Patel
Stefan Berger
Aleksa Sarai
Vishnu Kannan
Matthew Heon