mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-26 10:49:33 +00:00
![William Breathitt Gray](/assets/img/avatar_default.png)
The isa_driver structure for an isa_bus device is stored in the device
platform_data member of the respective device structure. This
platform_data member may be reset to NULL if isa_driver match callback
for the device fails, indicating a device unsupported by the ISA driver.
This patch fixes a possible NULL pointer dereference if one of the
isa_driver callbacks to attempted for an unsupported device. This error
should not occur in practice since ISA devices are typically manually
configured and loaded by the users, but we may as well prevent this
error from popping up for the 0day testers.
Fixes: a5117ba7da
("[PATCH] Driver model: add ISA bus")
Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Cc: stable <stable@vger.kernel.org>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
183 lines
3.8 KiB
C
183 lines
3.8 KiB
C
/*
|
|
* ISA bus.
|
|
*/
|
|
|
|
#include <linux/device.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/module.h>
|
|
#include <linux/init.h>
|
|
#include <linux/dma-mapping.h>
|
|
#include <linux/isa.h>
|
|
|
|
static struct device isa_bus = {
|
|
.init_name = "isa"
|
|
};
|
|
|
|
struct isa_dev {
|
|
struct device dev;
|
|
struct device *next;
|
|
unsigned int id;
|
|
};
|
|
|
|
#define to_isa_dev(x) container_of((x), struct isa_dev, dev)
|
|
|
|
static int isa_bus_match(struct device *dev, struct device_driver *driver)
|
|
{
|
|
struct isa_driver *isa_driver = to_isa_driver(driver);
|
|
|
|
if (dev->platform_data == isa_driver) {
|
|
if (!isa_driver->match ||
|
|
isa_driver->match(dev, to_isa_dev(dev)->id))
|
|
return 1;
|
|
dev->platform_data = NULL;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static int isa_bus_probe(struct device *dev)
|
|
{
|
|
struct isa_driver *isa_driver = dev->platform_data;
|
|
|
|
if (isa_driver && isa_driver->probe)
|
|
return isa_driver->probe(dev, to_isa_dev(dev)->id);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int isa_bus_remove(struct device *dev)
|
|
{
|
|
struct isa_driver *isa_driver = dev->platform_data;
|
|
|
|
if (isa_driver && isa_driver->remove)
|
|
return isa_driver->remove(dev, to_isa_dev(dev)->id);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void isa_bus_shutdown(struct device *dev)
|
|
{
|
|
struct isa_driver *isa_driver = dev->platform_data;
|
|
|
|
if (isa_driver && isa_driver->shutdown)
|
|
isa_driver->shutdown(dev, to_isa_dev(dev)->id);
|
|
}
|
|
|
|
static int isa_bus_suspend(struct device *dev, pm_message_t state)
|
|
{
|
|
struct isa_driver *isa_driver = dev->platform_data;
|
|
|
|
if (isa_driver && isa_driver->suspend)
|
|
return isa_driver->suspend(dev, to_isa_dev(dev)->id, state);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int isa_bus_resume(struct device *dev)
|
|
{
|
|
struct isa_driver *isa_driver = dev->platform_data;
|
|
|
|
if (isa_driver && isa_driver->resume)
|
|
return isa_driver->resume(dev, to_isa_dev(dev)->id);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static struct bus_type isa_bus_type = {
|
|
.name = "isa",
|
|
.match = isa_bus_match,
|
|
.probe = isa_bus_probe,
|
|
.remove = isa_bus_remove,
|
|
.shutdown = isa_bus_shutdown,
|
|
.suspend = isa_bus_suspend,
|
|
.resume = isa_bus_resume
|
|
};
|
|
|
|
static void isa_dev_release(struct device *dev)
|
|
{
|
|
kfree(to_isa_dev(dev));
|
|
}
|
|
|
|
void isa_unregister_driver(struct isa_driver *isa_driver)
|
|
{
|
|
struct device *dev = isa_driver->devices;
|
|
|
|
while (dev) {
|
|
struct device *tmp = to_isa_dev(dev)->next;
|
|
device_unregister(dev);
|
|
dev = tmp;
|
|
}
|
|
driver_unregister(&isa_driver->driver);
|
|
}
|
|
EXPORT_SYMBOL_GPL(isa_unregister_driver);
|
|
|
|
int isa_register_driver(struct isa_driver *isa_driver, unsigned int ndev)
|
|
{
|
|
int error;
|
|
unsigned int id;
|
|
|
|
isa_driver->driver.bus = &isa_bus_type;
|
|
isa_driver->devices = NULL;
|
|
|
|
error = driver_register(&isa_driver->driver);
|
|
if (error)
|
|
return error;
|
|
|
|
for (id = 0; id < ndev; id++) {
|
|
struct isa_dev *isa_dev;
|
|
|
|
isa_dev = kzalloc(sizeof *isa_dev, GFP_KERNEL);
|
|
if (!isa_dev) {
|
|
error = -ENOMEM;
|
|
break;
|
|
}
|
|
|
|
isa_dev->dev.parent = &isa_bus;
|
|
isa_dev->dev.bus = &isa_bus_type;
|
|
|
|
dev_set_name(&isa_dev->dev, "%s.%u",
|
|
isa_driver->driver.name, id);
|
|
isa_dev->dev.platform_data = isa_driver;
|
|
isa_dev->dev.release = isa_dev_release;
|
|
isa_dev->id = id;
|
|
|
|
isa_dev->dev.coherent_dma_mask = DMA_BIT_MASK(24);
|
|
isa_dev->dev.dma_mask = &isa_dev->dev.coherent_dma_mask;
|
|
|
|
error = device_register(&isa_dev->dev);
|
|
if (error) {
|
|
put_device(&isa_dev->dev);
|
|
break;
|
|
}
|
|
|
|
if (isa_dev->dev.platform_data) {
|
|
isa_dev->next = isa_driver->devices;
|
|
isa_driver->devices = &isa_dev->dev;
|
|
} else
|
|
device_unregister(&isa_dev->dev);
|
|
}
|
|
|
|
if (!error && !isa_driver->devices)
|
|
error = -ENODEV;
|
|
|
|
if (error)
|
|
isa_unregister_driver(isa_driver);
|
|
|
|
return error;
|
|
}
|
|
EXPORT_SYMBOL_GPL(isa_register_driver);
|
|
|
|
static int __init isa_bus_init(void)
|
|
{
|
|
int error;
|
|
|
|
error = bus_register(&isa_bus_type);
|
|
if (!error) {
|
|
error = device_register(&isa_bus);
|
|
if (error)
|
|
bus_unregister(&isa_bus_type);
|
|
}
|
|
return error;
|
|
}
|
|
|
|
postcore_initcall(isa_bus_init);
|