[PATCH] SELinux: Add security hook definition for getioprio and insert hooks

Add a new security hook definition for the sys_ioprio_get operation.  At
present, the SELinux hook function implementation for this hook is
identical to the getscheduler implementation but a separate hook is
introduced to allow this check to be specialized in the future if
necessary.

This patch also creates a helper function get_task_ioprio which handles the
access check in addition to retrieving the ioprio value for the task.

Signed-off-by: David Quigley <dpquigl@tycho.nsa.gov>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>
Cc: Jens Axboe <axboe@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

2 files changed, 12 insertions, 0 deletions

diff --git a/security/dummy.c b/security/dummy.c
index de53f6eb0c08..d417936562db 100644
--- a/security/dummy.c
+++ b/security/dummy.c
@@ -524,6 +524,11 @@ static int dummy_task_setioprio (struct task_struct *p, int ioprio)
         return 0;
 }
 
+static int dummy_task_getioprio (struct task_struct *p)
+{
+        return 0;
+}
+
 static int dummy_task_setrlimit (unsigned int resource, struct rlimit *new_rlim)
 {
         return 0;
@@ -988,6 +993,7 @@ void security_fixup_ops (struct security_operations *ops)
         set_to_dummy_if_null(ops, task_setgroups);
         set_to_dummy_if_null(ops, task_setnice);
         set_to_dummy_if_null(ops, task_setioprio);
+        set_to_dummy_if_null(ops, task_getioprio);
         set_to_dummy_if_null(ops, task_setrlimit);
         set_to_dummy_if_null(ops, task_setscheduler);
         set_to_dummy_if_null(ops, task_getscheduler);
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index a5189a347354..51bec4c88f19 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -2671,6 +2671,11 @@ static int selinux_task_setioprio(struct task_struct *p, int ioprio)
         return task_has_perm(current, p, PROCESS__SETSCHED);
 }
 
+static int selinux_task_getioprio(struct task_struct *p)
+{
+        return task_has_perm(current, p, PROCESS__GETSCHED);
+}
+
 static int selinux_task_setrlimit(unsigned int resource, struct rlimit *new_rlim)
 {
         struct rlimit *old_rlim = current->signal->rlim + resource;
@@ -4449,6 +4454,7 @@ static struct security_operations selinux_ops = {
         .task_setgroups =               selinux_task_setgroups,
         .task_setnice =                 selinux_task_setnice,
         .task_setioprio =               selinux_task_setioprio,
+        .task_getioprio =               selinux_task_getioprio,
         .task_setrlimit =               selinux_task_setrlimit,
         .task_setscheduler =            selinux_task_setscheduler,
         .task_getscheduler =            selinux_task_getscheduler,