userns: Convert cgroup permission checks to use uid_eq
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
diff --git a/init/Kconfig b/init/Kconfig
index 7a5ccb2e..d24cc75 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -865,7 +865,6 @@
# List of kernel pieces that need user namespace work
# Features
- depends on CGROUPS = n
depends on MIGRATION = n
depends on NUMA = n
depends on SYSVIPC = n
diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index ed64cca..c8329b0 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -2160,9 +2160,9 @@
* only need to check permissions on one of them.
*/
tcred = __task_cred(tsk);
- if (cred->euid &&
- cred->euid != tcred->uid &&
- cred->euid != tcred->suid) {
+ if (!uid_eq(cred->euid, GLOBAL_ROOT_UID) &&
+ !uid_eq(cred->euid, tcred->uid) &&
+ !uid_eq(cred->euid, tcred->suid)) {
rcu_read_unlock();
ret = -EACCES;
goto out_unlock_cgroup;