Commit 03e68060 authored by James Morris's avatar James Morris Committed by Linus Torvalds

[PATCH] lsm: add task_setioprio hook

Implement an LSM hook for setting a task's IO priority, similar to the hook
for setting a tasks's nice value.

A previous version of this LSM hook was included in an older version of
multiadm by Jan Engelhardt, although I don't recall it being submitted
upstream.

Also included is the corresponding SELinux hook, which re-uses the setsched
permission in the proccess class.
Signed-off-by: default avatarJames Morris <jmorris@namei.org>
Acked-by: default avatarStephen Smalley <sds@tycho.nsa.gov>
Cc: Jan Engelhardt <jengelh@linux01.gwdg.de>
Cc: Chris Wright <chrisw@sous-sol.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 9216dfad
......@@ -24,15 +24,21 @@
#include <linux/blkdev.h>
#include <linux/capability.h>
#include <linux/syscalls.h>
#include <linux/security.h>
static int set_task_ioprio(struct task_struct *task, int ioprio)
{
int err;
struct io_context *ioc;
if (task->uid != current->euid &&
task->uid != current->uid && !capable(CAP_SYS_NICE))
return -EPERM;
err = security_task_setioprio(task, ioprio);
if (err)
return err;
task_lock(task);
task->ioprio = ioprio;
......
......@@ -577,6 +577,11 @@ struct swap_info_struct;
* @p contains the task_struct of process.
* @nice contains the new nice value.
* Return 0 if permission is granted.
* @task_setioprio
* Check permission before setting the ioprio value of @p to @ioprio.
* @p contains the task_struct of process.
* @ioprio contains the new ioprio value
* 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
......@@ -1210,6 +1215,7 @@ struct security_operations {
int (*task_getsid) (struct task_struct * p);
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_setrlimit) (unsigned int resource, struct rlimit * new_rlim);
int (*task_setscheduler) (struct task_struct * p, int policy,
struct sched_param * lp);
......@@ -1836,6 +1842,11 @@ static inline int security_task_setnice (struct task_struct *p, int nice)
return security_ops->task_setnice (p, nice);
}
static inline int security_task_setioprio (struct task_struct *p, int ioprio)
{
return security_ops->task_setioprio (p, ioprio);
}
static inline int security_task_setrlimit (unsigned int resource,
struct rlimit *new_rlim)
{
......@@ -2478,6 +2489,11 @@ static inline int security_task_setnice (struct task_struct *p, int nice)
return 0;
}
static inline int security_task_setioprio (struct task_struct *p, int ioprio)
{
return 0;
}
static inline int security_task_setrlimit (unsigned int resource,
struct rlimit *new_rlim)
{
......
......@@ -516,6 +516,11 @@ static int dummy_task_setnice (struct task_struct *p, int nice)
return 0;
}
static int dummy_task_setioprio (struct task_struct *p, int ioprio)
{
return 0;
}
static int dummy_task_setrlimit (unsigned int resource, struct rlimit *new_rlim)
{
return 0;
......@@ -972,6 +977,7 @@ void security_fixup_ops (struct security_operations *ops)
set_to_dummy_if_null(ops, task_getsid);
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_setrlimit);
set_to_dummy_if_null(ops, task_setscheduler);
set_to_dummy_if_null(ops, task_getscheduler);
......
......@@ -2645,6 +2645,11 @@ static int selinux_task_setnice(struct task_struct *p, int nice)
return task_has_perm(current,p, PROCESS__SETSCHED);
}
static int selinux_task_setioprio(struct task_struct *p, int ioprio)
{
return task_has_perm(current, p, PROCESS__SETSCHED);
}
static int selinux_task_setrlimit(unsigned int resource, struct rlimit *new_rlim)
{
struct rlimit *old_rlim = current->signal->rlim + resource;
......@@ -4383,6 +4388,7 @@ static struct security_operations selinux_ops = {
.task_getsid = selinux_task_getsid,
.task_setgroups = selinux_task_setgroups,
.task_setnice = selinux_task_setnice,
.task_setioprio = selinux_task_setioprio,
.task_setrlimit = selinux_task_setrlimit,
.task_setscheduler = selinux_task_setscheduler,
.task_getscheduler = selinux_task_getscheduler,
......
Markdown is supported
0% or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment