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Commit 5704225c authored by Jorge Sanjuan Garcia's avatar Jorge Sanjuan Garcia Committed by Greg Kroah-Hartman
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mcb: remove is_added flag from mcb_device struct 



commit 0f28ada1fbf0054557cddcdb93ad17f767105208 upstream.

When calling mcb_bus_add_devices(), both mcb devices and the mcb
bus will attempt to attach a device to a driver because they share
the same bus_type. This causes an issue when trying to cast the
container of the device to mcb_device struct using to_mcb_device(),
leading to a wrong cast when the mcb_bus is added. A crash occurs
when freing the ida resources as the bus numbering of mcb_bus gets
confused with the is_added flag on the mcb_device struct.

The only reason for this cast was to keep an is_added flag on the
mcb_device struct that does not seem necessary. The function
device_attach() handles already bound devices and the mcb subsystem
does nothing special with this is_added flag so remove it completely.

Fixes: 18d28819 ("mcb: Correctly initialize the bus's device")
Cc: stable <stable@kernel.org>
Signed-off-by: default avatarJorge Sanjuan Garcia <jorge.sanjuangarcia@duagon.com>
Co-developed-by: default avatarJose Javier Rodriguez Barbarin <JoseJavier.Rodriguez@duagon.com>
Signed-off-by: default avatarJose Javier Rodriguez Barbarin <JoseJavier.Rodriguez@duagon.com>
Link: https://lore.kernel.org/r/20230906114901.63174-2-JoseJavier.Rodriguez@duagon.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 2bf6c93e

drivers/mcb/mcb-core.c

+3 −7
Original line number Diff line number Diff line
@@ -389,17 +389,13 @@ EXPORT_SYMBOL_GPL(mcb_free_dev); 


static int __mcb_bus_add_devices(struct device *dev, void *data)

{

	struct mcb_device *mdev = to_mcb_device(dev);

	int retval;



	if (mdev->is_added)

		return 0;



	retval = device_attach(dev);

	if (retval < 0)

	if (retval < 0) {

		dev_err(dev, "Error adding device (%d)\n", retval);



	mdev->is_added = true;

		return retval;

	}



	return 0;

}

drivers/mcb/mcb-parse.c

+0 −2
Original line number Diff line number Diff line
@@ -99,8 +99,6 @@ static int chameleon_parse_gdd(struct mcb_bus *bus, 
	mdev->mem.end = mdev->mem.start + size - 1;

	mdev->mem.flags = IORESOURCE_MEM;



	mdev->is_added = false;



	ret = mcb_device_register(bus, mdev);

	if (ret < 0)

		goto err;

include/linux/mcb.h

+0 −1
Original line number Diff line number Diff line
@@ -63,7 +63,6 @@ static inline struct mcb_bus *to_mcb_bus(struct device *dev) 
struct mcb_device {

	struct device dev;

	struct mcb_bus *bus;

	bool is_added;

	struct mcb_driver *driver;

	u16 id;

	int inst;