From: Thiébaud Weksteen tweek@google.com
commit 27709ae4e2fe6cf7da2ae45e718e190c5433342b upstream.
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: Thiébaud 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: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/usb/core/hcd.c | 123 --------------------------------------- drivers/usb/core/sysfs.c | 121 ++++++++++++++++++++++++++++++++++++++ drivers/usb/core/usb.h | 5 ++ 3 files changed, 126 insertions(+), 123 deletions(-)
diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c index 94d22551fc1bf..82e41179fb2db 100644 --- a/drivers/usb/core/hcd.c +++ b/drivers/usb/core/hcd.c @@ -101,11 +101,6 @@ 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); -} - /*-------------------------------------------------------------------------*/
/* @@ -878,101 +873,6 @@ 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, -}; - - - /*-------------------------------------------------------------------------*/
/** @@ -2895,32 +2795,11 @@ 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); @@ -2964,8 +2843,6 @@ 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; diff --git a/drivers/usb/core/sysfs.c b/drivers/usb/core/sysfs.c index 7e88fdfe3cf5c..f19694e69f5c3 100644 --- a/drivers/usb/core/sysfs.c +++ b/drivers/usb/core/sysfs.c @@ -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); diff --git a/drivers/usb/core/usb.h b/drivers/usb/core/usb.h index d95a5358f73df..d5ac492f441b1 100644 --- a/drivers/usb/core/usb.h +++ b/drivers/usb/core/usb.h @@ -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)