Commit 27709ae4 authored by Thiébaud Weksteen's avatar Thiébaud Weksteen Committed by Greg Kroah-Hartman
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usb: setup authorized_default attributes using usb_bus_notify 



Currently, the authorized_default and interface_authorized_default
attributes for HCD are set up after the uevent has been sent to userland.
This creates a race condition where userland may fail to access this
file when processing the event. Move the appending of these attributes
earlier relying on the usb_bus_notify dispatcher.

Signed-off-by: default avatarThiébaud Weksteen <tweek@google.com>
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20190806110050.38918-1-tweek@google.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent c468a8aa

drivers/usb/core/hcd.c

+0 −123
Original line number Diff line number Diff line
@@ -103,11 +103,6 @@ static DEFINE_SPINLOCK(hcd_urb_unlink_lock); 
/* wait queue for synchronous unlinks */

DECLARE_WAIT_QUEUE_HEAD(usb_kill_urb_queue);



static inline int is_root_hub(struct usb_device *udev)

{

	return (udev->parent == NULL);

}



/*-------------------------------------------------------------------------*/



/*
@@ -880,101 +875,6 @@ static int usb_rh_urb_dequeue(struct usb_hcd *hcd, struct urb *urb, int status) 
}







/*

 * Show & store the current value of authorized_default

 */

static ssize_t authorized_default_show(struct device *dev,

				       struct device_attribute *attr, char *buf)

{

	struct usb_device *rh_usb_dev = to_usb_device(dev);

	struct usb_bus *usb_bus = rh_usb_dev->bus;

	struct usb_hcd *hcd;



	hcd = bus_to_hcd(usb_bus);

	return snprintf(buf, PAGE_SIZE, "%u\n", hcd->dev_policy);

}



static ssize_t authorized_default_store(struct device *dev,

					struct device_attribute *attr,

					const char *buf, size_t size)

{

	ssize_t result;

	unsigned val;

	struct usb_device *rh_usb_dev = to_usb_device(dev);

	struct usb_bus *usb_bus = rh_usb_dev->bus;

	struct usb_hcd *hcd;



	hcd = bus_to_hcd(usb_bus);

	result = sscanf(buf, "%u\n", &val);

	if (result == 1) {

		hcd->dev_policy = val <= USB_DEVICE_AUTHORIZE_INTERNAL ?

			val : USB_DEVICE_AUTHORIZE_ALL;

		result = size;

	} else {

		result = -EINVAL;

	}

	return result;

}

static DEVICE_ATTR_RW(authorized_default);



/*

 * interface_authorized_default_show - show default authorization status

 * for USB interfaces

 *

 * note: interface_authorized_default is the default value

 *       for initializing the authorized attribute of interfaces

 */

static ssize_t interface_authorized_default_show(struct device *dev,

		struct device_attribute *attr, char *buf)

{

	struct usb_device *usb_dev = to_usb_device(dev);

	struct usb_hcd *hcd = bus_to_hcd(usb_dev->bus);



	return sprintf(buf, "%u\n", !!HCD_INTF_AUTHORIZED(hcd));

}



/*

 * interface_authorized_default_store - store default authorization status

 * for USB interfaces

 *

 * note: interface_authorized_default is the default value

 *       for initializing the authorized attribute of interfaces

 */

static ssize_t interface_authorized_default_store(struct device *dev,

		struct device_attribute *attr, const char *buf, size_t count)

{

	struct usb_device *usb_dev = to_usb_device(dev);

	struct usb_hcd *hcd = bus_to_hcd(usb_dev->bus);

	int rc = count;

	bool val;



	if (strtobool(buf, &val) != 0)

		return -EINVAL;



	if (val)

		set_bit(HCD_FLAG_INTF_AUTHORIZED, &hcd->flags);

	else

		clear_bit(HCD_FLAG_INTF_AUTHORIZED, &hcd->flags);



	return rc;

}

static DEVICE_ATTR_RW(interface_authorized_default);



/* Group all the USB bus attributes */

static struct attribute *usb_bus_attrs[] = {

		&dev_attr_authorized_default.attr,

		&dev_attr_interface_authorized_default.attr,

		NULL,

};



static const struct attribute_group usb_bus_attr_group = {

	.name = NULL,	/* we want them in the same directory */

	.attrs = usb_bus_attrs,

};







/*-------------------------------------------------------------------------*/



/**
@@ -2894,32 +2794,11 @@ int usb_add_hcd(struct usb_hcd *hcd, 
	if (retval != 0)

		goto err_register_root_hub;



	retval = sysfs_create_group(&rhdev->dev.kobj, &usb_bus_attr_group);

	if (retval < 0) {

		printk(KERN_ERR "Cannot register USB bus sysfs attributes: %d\n",

		       retval);

		goto error_create_attr_group;

	}

	if (hcd->uses_new_polling && HCD_POLL_RH(hcd))

		usb_hcd_poll_rh_status(hcd);



	return retval;



error_create_attr_group:

	clear_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);

	if (HC_IS_RUNNING(hcd->state))

		hcd->state = HC_STATE_QUIESCING;

	spin_lock_irq(&hcd_root_hub_lock);

	hcd->rh_registered = 0;

	spin_unlock_irq(&hcd_root_hub_lock);



#ifdef CONFIG_PM

	cancel_work_sync(&hcd->wakeup_work);

#endif

	cancel_work_sync(&hcd->died_work);

	mutex_lock(&usb_bus_idr_lock);

	usb_disconnect(&rhdev);		/* Sets rhdev to NULL */

	mutex_unlock(&usb_bus_idr_lock);

err_register_root_hub:

	hcd->rh_pollable = 0;

	clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
@@ -2963,8 +2842,6 @@ void usb_remove_hcd(struct usb_hcd *hcd) 
	dev_info(hcd->self.controller, "remove, state %x\n", hcd->state);



	usb_get_dev(rhdev);

	sysfs_remove_group(&rhdev->dev.kobj, &usb_bus_attr_group);



	clear_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);

	if (HC_IS_RUNNING (hcd->state))

		hcd->state = HC_STATE_QUIESCING;

drivers/usb/core/sysfs.c

+121 −0
Original line number Diff line number Diff line
@@ -15,6 +15,7 @@ 
#include <linux/kernel.h>

#include <linux/string.h>

#include <linux/usb.h>

#include <linux/usb/hcd.h>

#include <linux/usb/quirks.h>

#include <linux/of.h>

#include "usb.h"
@@ -922,6 +923,116 @@ static struct bin_attribute dev_bin_attr_descriptors = { 
	.size = 18 + 65535,	/* dev descr + max-size raw descriptor */

};



/*

 * Show & store the current value of authorized_default

 */

static ssize_t authorized_default_show(struct device *dev,

				       struct device_attribute *attr, char *buf)

{

	struct usb_device *rh_usb_dev = to_usb_device(dev);

	struct usb_bus *usb_bus = rh_usb_dev->bus;

	struct usb_hcd *hcd;



	hcd = bus_to_hcd(usb_bus);

	return snprintf(buf, PAGE_SIZE, "%u\n", hcd->dev_policy);

}



static ssize_t authorized_default_store(struct device *dev,

					struct device_attribute *attr,

					const char *buf, size_t size)

{

	ssize_t result;

	unsigned int val;

	struct usb_device *rh_usb_dev = to_usb_device(dev);

	struct usb_bus *usb_bus = rh_usb_dev->bus;

	struct usb_hcd *hcd;



	hcd = bus_to_hcd(usb_bus);

	result = sscanf(buf, "%u\n", &val);

	if (result == 1) {

		hcd->dev_policy = val <= USB_DEVICE_AUTHORIZE_INTERNAL ?

			val : USB_DEVICE_AUTHORIZE_ALL;

		result = size;

	} else {

		result = -EINVAL;

	}

	return result;

}

static DEVICE_ATTR_RW(authorized_default);



/*

 * interface_authorized_default_show - show default authorization status

 * for USB interfaces

 *

 * note: interface_authorized_default is the default value

 *       for initializing the authorized attribute of interfaces

 */

static ssize_t interface_authorized_default_show(struct device *dev,

		struct device_attribute *attr, char *buf)

{

	struct usb_device *usb_dev = to_usb_device(dev);

	struct usb_hcd *hcd = bus_to_hcd(usb_dev->bus);



	return sprintf(buf, "%u\n", !!HCD_INTF_AUTHORIZED(hcd));

}



/*

 * interface_authorized_default_store - store default authorization status

 * for USB interfaces

 *

 * note: interface_authorized_default is the default value

 *       for initializing the authorized attribute of interfaces

 */

static ssize_t interface_authorized_default_store(struct device *dev,

		struct device_attribute *attr, const char *buf, size_t count)

{

	struct usb_device *usb_dev = to_usb_device(dev);

	struct usb_hcd *hcd = bus_to_hcd(usb_dev->bus);

	int rc = count;

	bool val;



	if (strtobool(buf, &val) != 0)

		return -EINVAL;



	if (val)

		set_bit(HCD_FLAG_INTF_AUTHORIZED, &hcd->flags);

	else

		clear_bit(HCD_FLAG_INTF_AUTHORIZED, &hcd->flags);



	return rc;

}

static DEVICE_ATTR_RW(interface_authorized_default);



/* Group all the USB bus attributes */

static struct attribute *usb_bus_attrs[] = {

		&dev_attr_authorized_default.attr,

		&dev_attr_interface_authorized_default.attr,

		NULL,

};



static const struct attribute_group usb_bus_attr_group = {

	.name = NULL,	/* we want them in the same directory */

	.attrs = usb_bus_attrs,

};





static int add_default_authorized_attributes(struct device *dev)

{

	int rc = 0;



	if (is_usb_device(dev))

		rc = sysfs_create_group(&dev->kobj, &usb_bus_attr_group);



	return rc;

}



static void remove_default_authorized_attributes(struct device *dev)

{

	if (is_usb_device(dev)) {

		sysfs_remove_group(&dev->kobj, &usb_bus_attr_group);

	}

}



int usb_create_sysfs_dev_files(struct usb_device *udev)

{

	struct device *dev = &udev->dev;
@@ -938,7 +1049,14 @@ int usb_create_sysfs_dev_files(struct usb_device *udev) 
	retval = add_power_attributes(dev);

	if (retval)

		goto error;



	if (is_root_hub(udev)) {

		retval = add_default_authorized_attributes(dev);

		if (retval)

			goto error;

	}

	return retval;



error:

	usb_remove_sysfs_dev_files(udev);

	return retval;
@@ -948,6 +1066,9 @@ void usb_remove_sysfs_dev_files(struct usb_device *udev) 
{

	struct device *dev = &udev->dev;



	if (is_root_hub(udev))

		remove_default_authorized_attributes(dev);



	remove_power_attributes(dev);

	remove_persist_attributes(dev);

	device_remove_bin_file(dev, &dev_bin_attr_descriptors);

drivers/usb/core/usb.h

+5 −0
Original line number Diff line number Diff line
@@ -153,6 +153,11 @@ static inline int is_usb_port(const struct device *dev) 
	return dev->type == &usb_port_device_type;

}



static inline int is_root_hub(struct usb_device *udev)

{

	return (udev->parent == NULL);

}



/* Do the same for device drivers and interface drivers. */



static inline int is_usb_device_driver(struct device_driver *drv)

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