commit: a15d49fd3094cff90e5410ca454a870e0a722fe1 From: Hannes Reinecke <[email protected]> Date: Mon, 16 Apr 2012 15:06:25 +0200 Subject: driver core: check start node in klist_iter_init_node
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 <[email protected]> Cc: Greg Kroah-Hartmann <[email protected]> Cc: Kay Sievers <[email protected]> Cc: Stable Kernel <[email protected]> Cc: Linux Kernel <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- drivers/base/bus.c | 46 +++++++++++++++++++++++++++++----------------- drivers/base/class.c | 32 ++++++++++++++++++++------------ drivers/base/driver.c | 18 +++++++++++------- include/linux/device.h | 10 +++++----- include/linux/klist.h | 2 +- lib/klist.c | 14 ++++++++++---- 6 files changed, 76 insertions(+), 46 deletions(-) diff --git a/drivers/base/bus.c b/drivers/base/bus.c index 2bcef65..76aed01 100644 --- a/drivers/base/bus.c +++ b/drivers/base/bus.c @@ -296,11 +296,13 @@ 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); @@ -330,8 +332,10 @@ 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; @@ -384,7 +388,9 @@ 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); @@ -446,11 +452,13 @@ 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); @@ -1111,15 +1119,19 @@ 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); -- 1.7.3.4 -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
