From: David Quigley <[email protected]>
This patch adds 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 <[email protected]>
Acked-by: Stephen Smalley <[email protected]>
Signed-off-by: James Morris <[email protected]>
Please apply.
---
fs/ioprio.c | 29 ++++++++++++++++++++++++-----
include/linux/security.h | 15 +++++++++++++++
security/dummy.c | 6 ++++++
security/selinux/hooks.c | 6 ++++++
4 files changed, 51 insertions(+), 5 deletions(-)
diff -uprN -X /home/dpquigl/dontdiff linux-2.6.17-mm3/fs/ioprio.c linux-2.6.17-mm3-ioprio/fs/ioprio.c
--- linux-2.6.17-mm3/fs/ioprio.c 2006-06-28 13:58:56.000000000 -0400
+++ linux-2.6.17-mm3-ioprio/fs/ioprio.c 2006-06-29 15:58:29.000000000 -0400
@@ -125,11 +125,24 @@ asmlinkage long sys_ioprio_set(int which
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
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
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)
diff -uprN -X /home/dpquigl/dontdiff linux-2.6.17-mm3/include/linux/security.h linux-2.6.17-mm3-ioprio/include/linux/security.h
--- linux-2.6.17-mm3/include/linux/security.h 2006-06-28 13:58:59.000000000 -0400
+++ linux-2.6.17-mm3-ioprio/include/linux/security.h 2006-06-28 11:21:37.000000000 -0400
@@ -582,6 +582,10 @@ 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
@@ -1221,6 +1225,7 @@ 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);
@@ -1853,6 +1858,11 @@ static inline int security_task_setiopri
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)
{
@@ -2505,6 +2515,11 @@ static inline int security_task_setiopri
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)
{
diff -uprN -X /home/dpquigl/dontdiff linux-2.6.17-mm3/security/dummy.c linux-2.6.17-mm3-ioprio/security/dummy.c
--- linux-2.6.17-mm3/security/dummy.c 2006-06-28 13:58:59.000000000 -0400
+++ linux-2.6.17-mm3-ioprio/security/dummy.c 2006-06-28 11:23:00.000000000 -0400
@@ -521,6 +521,11 @@ static int dummy_task_setioprio (struct
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;
@@ -984,6 +989,7 @@ void security_fixup_ops (struct security
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 -uprN -X /home/dpquigl/dontdiff linux-2.6.17-mm3/security/selinux/hooks.c linux-2.6.17-mm3-ioprio/security/selinux/hooks.c
--- linux-2.6.17-mm3/security/selinux/hooks.c 2006-06-28 13:58:59.000000000 -0400
+++ linux-2.6.17-mm3-ioprio/security/selinux/hooks.c 2006-06-28 11:49:13.000000000 -0400
@@ -2665,6 +2665,11 @@ static int selinux_task_setioprio(struct
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;
@@ -4432,6 +4437,7 @@ static struct security_operations selinu
.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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