When we parse the device tree and allocate platform
devices, the 'name' of the newly-created platform_device
is set to point to the 'name' field of the 'struct device'
embedded within the platform_device. This is dangerous,
because the name of the 'struct device' is dynamically
allocated. Drivers may call dev_set_name() on the device,
which will free and reallocate the name of the device,
leaving the 'name' of the platform_device pointing to the
now-freed memory.
Furthermore, if the dev_set_name() call is made from a
driver's probe() function and a subsequent request results
in probe deferral, the dangling 'name' reference may lead
to the device being re-probed using the wrong driver.
To mitigate these scenarios, we use kstrdup to perform a
deep copy of the device name when assigning the name of the
platform_device, so that the platform_device name is
unaffected by any calls to dev_set_name() that might made
by drivers to rename the embedded 'struct device'.
Signed-off-by: Stepan Moskovchenko <stepanm@xxxxxxxxxxxxxx>
---
* v2 - swap cleanup order
drivers/of/device.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/of/device.c b/drivers/of/device.c
index f685e55..e9beae6 100644
--- a/drivers/of/device.c
+++ b/drivers/of/device.c
@@ -54,7 +54,7 @@ int of_device_add(struct platform_device *ofdev)
/* name and id have to be set so that the platform bus doesn't get
* confused on matching */
- ofdev->name = dev_name(&ofdev->dev);
+ ofdev->name = kstrdup(dev_name(&ofdev->dev), GFP_KERNEL);
ofdev->id = -1;
/* device_add will assume that this device is on the same node as
@@ -75,6 +75,7 @@ EXPORT_SYMBOL(of_device_register);
void of_device_unregister(struct platform_device *ofdev)
{
+ kfree(ofdev->name);
device_unregister(&ofdev->dev);
}
EXPORT_SYMBOL(of_device_unregister);
--
The Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
hosted by The Linux Foundation
--
To unsubscribe from this list: send the line "unsubscribe devicetree" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
