| From 3a2a91a2d51761557843996a66098eb7182b48b4 Mon Sep 17 00:00:00 2001 |
| From: Hans de Goede <hdegoede@redhat.com> |
| Date: Fri, 9 Apr 2021 14:41:36 +0200 |
| Subject: usb: roles: Call try_module_get() from usb_role_switch_find_by_fwnode() |
| |
| From: Hans de Goede <hdegoede@redhat.com> |
| |
| commit 3a2a91a2d51761557843996a66098eb7182b48b4 upstream. |
| |
| usb_role_switch_find_by_fwnode() returns a reference to the role-switch |
| which must be put by calling usb_role_switch_put(). |
| |
| usb_role_switch_put() calls module_put(sw->dev.parent->driver->owner), |
| add a matching try_module_get() to usb_role_switch_find_by_fwnode(), |
| making it behave the same as the other usb_role_switch functions |
| which return a reference. |
| |
| This avoids a WARN_ON being hit at kernel/module.c:1158 due to the |
| module-refcount going below 0. |
| |
| Fixes: c6919d5e0cd1 ("usb: roles: Add usb_role_switch_find_by_fwnode()") |
| Cc: stable <stable@vger.kernel.org> |
| Reviewed-by: Guenter Roeck <linux@roeck-us.net> |
| Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> |
| Signed-off-by: Hans de Goede <hdegoede@redhat.com> |
| Link: https://lore.kernel.org/r/20210409124136.65591-1-hdegoede@redhat.com |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| --- |
| drivers/usb/roles/class.c | 2 ++ |
| 1 file changed, 2 insertions(+) |
| |
| --- a/drivers/usb/roles/class.c |
| +++ b/drivers/usb/roles/class.c |
| @@ -189,6 +189,8 @@ usb_role_switch_find_by_fwnode(const str |
| return NULL; |
| |
| dev = class_find_device_by_fwnode(role_class, fwnode); |
| + if (dev) |
| + WARN_ON(!try_module_get(dev->parent->driver->owner)); |
| |
| return dev ? to_role_switch(dev) : NULL; |
| } |
