lkml.org 
[lkml]   [2012]   [Apr]   [16]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH] driver core: check start node in klist_iter_init_node
Date
klist_iter_init_node() takes a node as a start argument.
However, this node might not be valid anymore.
This patch updates the klist_iter_init_node() and
dependent functions to return an error if so.
All calling functions have been audited to check
for a return code here.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Cc: Greg Kroah-Hartmann <gregkh@linuxfoundation.org>
Cc: Kay Sievers <kay@vrfy.org>
Cc: Stable Kernel <stable@kernel.org>
Cc: Linux Kernel <linux-kernel@vger.kernel.org>

diff --git a/drivers/base/bus.c b/drivers/base/bus.c
index 26a06b8..a2152a6 100644
--- a/drivers/base/bus.c
+++ b/drivers/base/bus.c
@@ -297,11 +297,13 @@ int bus_for_each_dev(struct bus_type *bus, struct device *start,
if (!bus)
return -EINVAL;

- klist_iter_init_node(&bus->p->klist_devices, &i,
- (start ? &start->p->knode_bus : NULL));
- while ((dev = next_device(&i)) && !error)
- error = fn(dev, data);
- klist_iter_exit(&i);
+ error = klist_iter_init_node(&bus->p->klist_devices, &i,
+ (start ? &start->p->knode_bus : NULL));
+ if (!error) {
+ while ((dev = next_device(&i)) && !error)
+ error = fn(dev, data);
+ klist_iter_exit(&i);
+ }
return error;
}
EXPORT_SYMBOL_GPL(bus_for_each_dev);
@@ -331,8 +333,10 @@ struct device *bus_find_device(struct bus_type *bus,
if (!bus)
return NULL;

- klist_iter_init_node(&bus->p->klist_devices, &i,
- (start ? &start->p->knode_bus : NULL));
+ if (klist_iter_init_node(&bus->p->klist_devices, &i,
+ (start ? &start->p->knode_bus : NULL)) < 0)
+ return NULL;
+
while ((dev = next_device(&i)))
if (match(dev, data) && get_device(dev))
break;
@@ -385,7 +389,9 @@ struct device *subsys_find_device_by_id(struct bus_type *subsys, unsigned int id
return NULL;

if (hint) {
- klist_iter_init_node(&subsys->p->klist_devices, &i, &hint->p->knode_bus);
+ if (klist_iter_init_node(&subsys->p->klist_devices, &i,
+ &hint->p->knode_bus) < 0)
+ return NULL;
dev = next_device(&i);
if (dev && dev->id == id && get_device(dev)) {
klist_iter_exit(&i);
@@ -447,11 +453,13 @@ int bus_for_each_drv(struct bus_type *bus, struct device_driver *start,
if (!bus)
return -EINVAL;

- klist_iter_init_node(&bus->p->klist_drivers, &i,
- start ? &start->p->knode_bus : NULL);
- while ((drv = next_driver(&i)) && !error)
- error = fn(drv, data);
- klist_iter_exit(&i);
+ error = klist_iter_init_node(&bus->p->klist_drivers, &i,
+ start ? &start->p->knode_bus : NULL);
+ if (!error) {
+ while ((drv = next_driver(&i)) && !error)
+ error = fn(drv, data);
+ klist_iter_exit(&i);
+ }
return error;
}
EXPORT_SYMBOL_GPL(bus_for_each_drv);
@@ -1112,15 +1120,19 @@ EXPORT_SYMBOL_GPL(bus_sort_breadthfirst);
* otherwise if it is NULL, the iteration starts at the beginning of
* the list.
*/
-void subsys_dev_iter_init(struct subsys_dev_iter *iter, struct bus_type *subsys,
- struct device *start, const struct device_type *type)
+int subsys_dev_iter_init(struct subsys_dev_iter *iter, struct bus_type *subsys,
+ struct device *start, const struct device_type *type)
{
struct klist_node *start_knode = NULL;
+ int error;

if (start)
start_knode = &start->p->knode_bus;
- klist_iter_init_node(&subsys->p->klist_devices, &iter->ki, start_knode);
- iter->type = type;
+ error = klist_iter_init_node(&subsys->p->klist_devices, &iter->ki,
+ start_knode);
+ if (!error)
+ iter->type = type;
+ return error;
}
EXPORT_SYMBOL_GPL(subsys_dev_iter_init);

diff --git a/drivers/base/class.c b/drivers/base/class.c
index 03243d4..23dbc66 100644
--- a/drivers/base/class.c
+++ b/drivers/base/class.c
@@ -301,15 +301,20 @@ void class_destroy(struct class *cls)
* otherwise if it is NULL, the iteration starts at the beginning of
* the list.
*/
-void class_dev_iter_init(struct class_dev_iter *iter, struct class *class,
- struct device *start, const struct device_type *type)
+int class_dev_iter_init(struct class_dev_iter *iter, struct class *class,
+ struct device *start, const struct device_type *type)
{
struct klist_node *start_knode = NULL;
+ int error;

if (start)
start_knode = &start->knode_class;
- klist_iter_init_node(&class->p->klist_devices, &iter->ki, start_knode);
- iter->type = type;
+ error = klist_iter_init_node(&class->p->klist_devices, &iter->ki,
+ start_knode);
+ if (!error)
+ iter->type = type;
+
+ return error;
}
EXPORT_SYMBOL_GPL(class_dev_iter_init);

@@ -387,14 +392,15 @@ int class_for_each_device(struct class *class, struct device *start,
return -EINVAL;
}

- class_dev_iter_init(&iter, class, start, NULL);
- while ((dev = class_dev_iter_next(&iter))) {
- error = fn(dev, data);
- if (error)
- break;
+ error = class_dev_iter_init(&iter, class, start, NULL);
+ if (!error) {
+ while ((dev = class_dev_iter_next(&iter))) {
+ error = fn(dev, data);
+ if (error)
+ break;
+ }
+ class_dev_iter_exit(&iter);
}
- class_dev_iter_exit(&iter);
-
return error;
}
EXPORT_SYMBOL_GPL(class_for_each_device);
@@ -434,7 +440,9 @@ struct device *class_find_device(struct class *class, struct device *start,
return NULL;
}

- class_dev_iter_init(&iter, class, start, NULL);
+ if (class_dev_iter_init(&iter, class, start, NULL) < 0)
+ return NULL;
+
while ((dev = class_dev_iter_next(&iter))) {
if (match(dev, data)) {
get_device(dev);
diff --git a/drivers/base/driver.c b/drivers/base/driver.c
index 3ec3896..16f6dd2 100644
--- a/drivers/base/driver.c
+++ b/drivers/base/driver.c
@@ -49,11 +49,13 @@ int driver_for_each_device(struct device_driver *drv, struct device *start,
if (!drv)
return -EINVAL;

- klist_iter_init_node(&drv->p->klist_devices, &i,
- start ? &start->p->knode_driver : NULL);
- while ((dev = next_device(&i)) && !error)
- error = fn(dev, data);
- klist_iter_exit(&i);
+ error = klist_iter_init_node(&drv->p->klist_devices, &i,
+ start ? &start->p->knode_driver : NULL);
+ if (!error) {
+ while ((dev = next_device(&i)) && !error)
+ error = fn(dev, data);
+ klist_iter_exit(&i);
+ }
return error;
}
EXPORT_SYMBOL_GPL(driver_for_each_device);
@@ -83,8 +85,10 @@ struct device *driver_find_device(struct device_driver *drv,
if (!drv)
return NULL;

- klist_iter_init_node(&drv->p->klist_devices, &i,
- (start ? &start->p->knode_driver : NULL));
+ if (klist_iter_init_node(&drv->p->klist_devices, &i,
+ (start ? &start->p->knode_driver : NULL)) < 0)
+ return NULL;
+
while ((dev = next_device(&i)))
if (match(dev, data) && get_device(dev))
break;
diff --git a/include/linux/device.h b/include/linux/device.h
index 5ad17cc..50429b9 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -128,7 +128,7 @@ struct subsys_dev_iter {
struct klist_iter ki;
const struct device_type *type;
};
-void subsys_dev_iter_init(struct subsys_dev_iter *iter,
+int subsys_dev_iter_init(struct subsys_dev_iter *iter,
struct bus_type *subsys,
struct device *start,
const struct device_type *type);
@@ -380,10 +380,10 @@ int class_compat_create_link(struct class_compat *cls, struct device *dev,
void class_compat_remove_link(struct class_compat *cls, struct device *dev,
struct device *device_link);

-extern void class_dev_iter_init(struct class_dev_iter *iter,
- struct class *class,
- struct device *start,
- const struct device_type *type);
+extern int class_dev_iter_init(struct class_dev_iter *iter,
+ struct class *class,
+ struct device *start,
+ const struct device_type *type);
extern struct device *class_dev_iter_next(struct class_dev_iter *iter);
extern void class_dev_iter_exit(struct class_dev_iter *iter);

diff --git a/include/linux/klist.h b/include/linux/klist.h
index a370ce5..9f63323 100644
--- a/include/linux/klist.h
+++ b/include/linux/klist.h
@@ -60,7 +60,7 @@ struct klist_iter {


extern void klist_iter_init(struct klist *k, struct klist_iter *i);
-extern void klist_iter_init_node(struct klist *k, struct klist_iter *i,
+extern int klist_iter_init_node(struct klist *k, struct klist_iter *i,
struct klist_node *n);
extern void klist_iter_exit(struct klist_iter *i);
extern struct klist_node *klist_next(struct klist_iter *i);
diff --git a/lib/klist.c b/lib/klist.c
index 0874e41..a2741a7 100644
--- a/lib/klist.c
+++ b/lib/klist.c
@@ -278,13 +278,19 @@ EXPORT_SYMBOL_GPL(klist_node_attached);
* Similar to klist_iter_init(), but starts the action off with @n,
* instead of with the list head.
*/
-void klist_iter_init_node(struct klist *k, struct klist_iter *i,
- struct klist_node *n)
+int klist_iter_init_node(struct klist *k, struct klist_iter *i,
+ struct klist_node *n)
{
+ if (n) {
+ kref_get(&n->n_ref);
+ if (!n->n_klist) {
+ kref_put(&n->n_ref);
+ return -ENODEV;
+ }
+ }
i->i_klist = k;
i->i_cur = n;
- if (n)
- kref_get(&n->n_ref);
+ return 0;
}
EXPORT_SYMBOL_GPL(klist_iter_init_node);


\
 
 \ /
  Last update: 2012-04-16 15:09    [W:0.029 / U:1.592 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site