Commit a1836a42 authored by David Quigley's avatar David Quigley Committed by Linus Torvalds

[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: default avatarDavid Quigley <dpquigl@tycho.nsa.gov>
Acked-by: default avatarStephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: default avatarJames Morris <jmorris@namei.org>
Cc: Jens Axboe <axboe@suse.de>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 7a01955f
......@@ -125,11 +125,24 @@ asmlinkage long sys_ioprio_set(int which, int who, int ioprio)
return ret;
}
static int get_task_ioprio(struct task_struct *p)
{
int ret;
ret = security_task_getioprio(p);
if (ret)
goto out;
ret = p->ioprio;
out:
return ret;
}
asmlinkage long sys_ioprio_get(int which, int who)
{
struct task_struct *g, *p;
struct user_struct *user;
int ret = -ESRCH;
int tmpio;
read_lock_irq(&tasklist_lock);
switch (which) {
......@@ -139,16 +152,19 @@ asmlinkage long sys_ioprio_get(int which, int who)
else
p = find_task_by_pid(who);
if (p)
ret = p->ioprio;
ret = get_task_ioprio(p);
break;
case IOPRIO_WHO_PGRP:
if (!who)
who = process_group(current);
do_each_task_pid(who, PIDTYPE_PGID, p) {
tmpio = get_task_ioprio(p);
if (tmpio < 0)
continue;
if (ret == -ESRCH)
ret = p->ioprio;
ret = tmpio;
else
ret = ioprio_best(ret, p->ioprio);
ret = ioprio_best(ret, tmpio);
} while_each_task_pid(who, PIDTYPE_PGID, p);
break;
case IOPRIO_WHO_USER:
......@@ -163,10 +179,13 @@ asmlinkage long sys_ioprio_get(int which, int who)
do_each_thread(g, p) {
if (p->uid != user->uid)
continue;
tmpio = get_task_ioprio(p);
if (tmpio < 0)
continue;
if (ret == -ESRCH)
ret = p->ioprio;
ret = tmpio;
else
ret = ioprio_best(ret, p->ioprio);
ret = ioprio_best(ret, tmpio);
} while_each_thread(g, p);
if (who)
......
......@@ -585,6 +585,10 @@ struct swap_info_struct;
* @p contains the task_struct of process.
* @ioprio contains the new ioprio value
* Return 0 if permission is granted.
* @task_getioprio
* Check permission before getting the ioprio value of @p.
* @p contains the task_struct of process.
* Return 0 if permission is granted.
* @task_setrlimit:
* Check permission before setting the resource limits of the current
* process for @resource to @new_rlim. The old resource limit values can
......@@ -1227,6 +1231,7 @@ struct security_operations {
int (*task_setgroups) (struct group_info *group_info);
int (*task_setnice) (struct task_struct * p, int nice);
int (*task_setioprio) (struct task_struct * p, int ioprio);
int (*task_getioprio) (struct task_struct * p);
int (*task_setrlimit) (unsigned int resource, struct rlimit * new_rlim);
int (*task_setscheduler) (struct task_struct * p, int policy,
struct sched_param * lp);
......@@ -1864,6 +1869,11 @@ static inline int security_task_setioprio (struct task_struct *p, int ioprio)
return security_ops->task_setioprio (p, ioprio);
}
static inline int security_task_getioprio (struct task_struct *p)
{
return security_ops->task_getioprio (p);
}
static inline int security_task_setrlimit (unsigned int resource,
struct rlimit *new_rlim)
{
......@@ -2520,6 +2530,11 @@ static inline int security_task_setioprio (struct task_struct *p, int ioprio)
return 0;
}
static inline int security_task_getioprio (struct task_struct *p)
{
return 0;
}
static inline int security_task_setrlimit (unsigned int resource,
struct rlimit *new_rlim)
{
......
......@@ -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);
......
......@@ -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,
......
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