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: 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>
diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c
index 9320787..2ccbc2f 100644
--- a/drivers/usb/core/hcd.c
+++ b/drivers/usb/core/hcd.c
@@ -103,11 +103,6 @@
/* 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 @@
}
-
-/*
- * 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 @@
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 @@
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 7e88fdf..f19694e 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 @@
.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 @@
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 @@
{
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 bd8d01f..0c9fde5a 100644
--- a/drivers/usb/core/usb.h
+++ b/drivers/usb/core/usb.h
@@ -153,6 +153,11 @@
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)
