proc,security: move restriction on writing /proc/pid/attr nodes to proc
Processes can only alter their own security attributes via
/proc/pid/attr nodes. This is presently enforced by each individual
security module and is also imposed by the Linux credentials
implementation, which only allows a task to alter its own credentials.
Move the check enforcing this restriction from the individual
security modules to proc_pid_attr_write() before calling the security hook,
and drop the unnecessary task argument to the security hook since it can
only ever be the current task.
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Acked-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
diff --git a/security/apparmor/lsm.c b/security/apparmor/lsm.c
index 41b8cb1..8202e55 100644
--- a/security/apparmor/lsm.c
+++ b/security/apparmor/lsm.c
@@ -495,8 +495,8 @@ static int apparmor_getprocattr(struct task_struct *task, char *name,
return error;
}
-static int apparmor_setprocattr(struct task_struct *task, char *name,
- void *value, size_t size)
+static int apparmor_setprocattr(const char *name, void *value,
+ size_t size)
{
struct common_audit_data sa;
struct apparmor_audit_data aad = {0,};
@@ -506,9 +506,6 @@ static int apparmor_setprocattr(struct task_struct *task, char *name,
if (size == 0)
return -EINVAL;
- /* task can only write its own attributes */
- if (current != task)
- return -EACCES;
/* AppArmor requires that the buffer must be null terminated atm */
if (args[size - 1] != '\0') {