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

fs/ioprio.c

+24 −5
Original line number Diff line number Diff line
@@ -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)

include/linux/security.h

+15 −0
Original line number Diff line number Diff line
@@ -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)

{

security/dummy.c

+6 −0
Original line number Diff line number Diff line
@@ -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);

security/selinux/hooks.c

+6 −0
Original line number Diff line number Diff line
@@ -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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