diff options
| author | San Mehat <san@google.com> | 2009-05-21 14:10:06 -0700 |
|---|---|---|
| committer | Colin Cross <ccross@android.com> | 2010-09-29 17:49:18 -0700 |
| commit | c316a1d4a0867c767cda23397e634e28905a8cc7 (patch) | |
| tree | d38b560d4fdac7565eee2450259e8f78e78fcfdb /kernel/cgroup.c | |
| parent | b8aab015cd2af37c45d95967de1122825ce4d90d (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
'can_attach' handler, then we fall back to doing our checks the old way.
This way non-root processes can add arbitrary processes to
a cgroup if all the registered subsystems on that cgroup agree.
Also change explicit euid == 0 check to CAP_SYS_ADMIN
Signed-off-by: San Mehat <san@google.com>
Diffstat (limited to 'kernel/cgroup.c')
| -rw-r--r-- | kernel/cgroup.c | 18 |
1 files changed, 9 insertions, 9 deletions
diff --git a/kernel/cgroup.c b/kernel/cgroup.c index c9483d8f6140..f3d6f30c8cd1 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -58,6 +58,7 @@ #include <linux/vmalloc.h> /* TODO: replace with more sophisticated array */ #include <linux/eventfd.h> #include <linux/poll.h> +#include <linux/capability.h> #include <asm/atomic.h> @@ -1722,6 +1723,14 @@ int cgroup_attach_task(struct cgroup *cgrp, struct task_struct *tsk) */ failed_ss = ss; goto out; + } else if (!capable(CAP_SYS_ADMIN)) { + const struct cred *cred = current_cred(), *tcred; + + /* No can_attach() - check perms generically */ + tcred = __task_cred(tsk); + if (cred->euid != tcred->uid && + cred->euid != tcred->suid) { + return -EACCES; } } } @@ -1821,7 +1830,6 @@ EXPORT_SYMBOL_GPL(cgroup_attach_task_all); static int attach_task_by_pid(struct cgroup *cgrp, u64 pid) { struct task_struct *tsk; - const struct cred *cred = current_cred(), *tcred; int ret; if (pid) { @@ -1831,14 +1839,6 @@ static int attach_task_by_pid(struct cgroup *cgrp, u64 pid) rcu_read_unlock(); return -ESRCH; } - - tcred = __task_cred(tsk); - if (cred->euid && - cred->euid != tcred->uid && - cred->euid != tcred->suid) { - rcu_read_unlock(); - return -EACCES; - } get_task_struct(tsk); rcu_read_unlock(); } else { |