Commit 27709ae4 authored by Thiébaud Weksteen's avatar Thiébaud Weksteen Committed by Greg Kroah-Hartman

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