diff options
| author |   Heikki Krogerus <heikki.krogerus@linux.intel.com> | 2018-09-19 10:58:05 +0300 |
|---|---|---|
| committer |   Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-09-20 13:20:24 +0200 |
| commit | 5c54fcac9a9de559b444ac63ec3cd82f1d157a0b (patch) | |
| tree | 06e3af99439cd5ca1fe7700f88b74d2bee2cc079 /drivers/usb/common | |
| parent | USB: handle NULL config in usb_find_alt_setting() (diff) | |
| download | linux-dev-5c54fcac9a9de559b444ac63ec3cd82f1d157a0b.tar.xz linux-dev-5c54fcac9a9de559b444ac63ec3cd82f1d157a0b.zip | |
usb: roles: Take care of driver module reference counting
This fixes potential "BUG: unable to handle kernel paging
request at ..." from happening.
Fixes: fde0aa6c175a ("usb: common: Small class for USB role switches")
Cc: <stable@vger.kernel.org>
Acked-by: Hans de Goede <hdegoede@redhat.com>
Tested-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/usb/common')
| -rw-r--r-- | drivers/usb/common/roles.c | 15 |
1 files changed, 12 insertions, 3 deletions
diff --git a/drivers/usb/common/roles.c b/drivers/usb/common/roles.c index 15cc76e22123..99116af07f1d 100644 --- a/drivers/usb/common/roles.c +++ b/drivers/usb/common/roles.c @@ -109,8 +109,15 @@ static void *usb_role_switch_match(struct device_connection *con, int ep, */ struct usb_role_switch *usb_role_switch_get(struct device *dev) { - return device_connection_find_match(dev, "usb-role-switch", NULL, - usb_role_switch_match); + struct usb_role_switch *sw; + + sw = device_connection_find_match(dev, "usb-role-switch", NULL, + usb_role_switch_match); + + if (!IS_ERR_OR_NULL(sw)) + WARN_ON(!try_module_get(sw->dev.parent->driver->owner)); + + return sw; } EXPORT_SYMBOL_GPL(usb_role_switch_get); @@ -122,8 +129,10 @@ EXPORT_SYMBOL_GPL(usb_role_switch_get); */ void usb_role_switch_put(struct usb_role_switch *sw) { - if (!IS_ERR_OR_NULL(sw)) + if (!IS_ERR_OR_NULL(sw)) { put_device(&sw->dev); + module_put(sw->dev.parent->driver->owner); + } } EXPORT_SYMBOL_GPL(usb_role_switch_put); |