diff options
| author | Colin Cross <ccross@android.com> | 2011-07-12 19:53:24 -0700 |
|---|---|---|
| committer | Praneeth Bajjuri <praneeth@ti.com> | 2011-09-20 16:59:57 -0700 |
| commit | 0c7fe33e5fe277ebc0676eca5143dc809bfac0a2 (patch) | |
| tree | 6aca0637b89871b6daada25fd454e32202cf076e /kernel/sched.c | |
| parent | e475aef9ac0b788d05ed6dec0f839b49ae819591 (diff) | |
cgroup: Add generic cgroup subsystem permission checks
Rather than using explicit euid == 0 checks when trying to move
tasks into a cgroup via CFS, move permission checks into each
specific cgroup subsystem. If a subsystem does not specify a
'allow_attach' handler, then we fall back to doing our checks
the old way.
Use the 'allow_attach' handler for the 'cpu' cgroup to allow
non-root processes to add arbitrary processes to a 'cpu' cgroup
if it has the CAP_SYS_NICE capability set.
This version of the patch adds a 'allow_attach' handler instead
of reusing the 'can_attach' handler. If the 'can_attach' handler
is reused, a new cgroup that implements 'can_attach' but not
the permission checks could end up with no permission checks
at all.
Change-Id: Icfa950aa9321d1ceba362061d32dc7dfa2c64f0c
Original-Author: San Mehat <san@google.com>
Signed-off-by: Colin Cross <ccross@android.com>
Diffstat (limited to 'kernel/sched.c')
| -rw-r--r-- | kernel/sched.c | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/kernel/sched.c b/kernel/sched.c index b4a97528b52..f065d66695e 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -8991,6 +8991,20 @@ cpu_cgroup_destroy(struct cgroup_subsys *ss, struct cgroup *cgrp) } static int +cpu_cgroup_allow_attach(struct cgroup *cgrp, struct task_struct *tsk) +{ + const struct cred *cred = current_cred(), *tcred; + + tcred = __task_cred(tsk); + + if ((current != tsk) && !capable(CAP_SYS_NICE) && + cred->euid != tcred->uid && cred->euid != tcred->suid) + return -EACCES; + + return 0; +} + +static int cpu_cgroup_can_attach_task(struct cgroup *cgrp, struct task_struct *tsk) { #ifdef CONFIG_RT_GROUP_SCHED @@ -9095,6 +9109,7 @@ struct cgroup_subsys cpu_cgroup_subsys = { .name = "cpu", .create = cpu_cgroup_create, .destroy = cpu_cgroup_destroy, + .allow_attach = cpu_cgroup_allow_attach, .can_attach_task = cpu_cgroup_can_attach_task, .attach_task = cpu_cgroup_attach_task, .exit = cpu_cgroup_exit, |