| From | Greg Kroah-Hartman <> | Subject | [PATCH 5.11 006/601] usb: roles: Call try_module_get() from usb_role_switch_find_by_fwnode() | Date | Wed, 12 May 2021 16:41:23 +0200 |
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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; }
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