This is a note to let you know that I've just added the patch titled
usb: roles: Take care of driver module reference counting
to my usb git tree which can be found at
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git
in the usb-linus branch.
The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)
The patch will hopefully also be merged in Linus's tree for the
next -rc kernel release.
If you have any questions about this process, please let me know.
>From 5c54fcac9a9de559b444ac63ec3cd82f1d157a0b Mon Sep 17 00:00:00 2001
From: Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx>
Date: Wed, 19 Sep 2018 10:58:05 +0300
Subject: 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@xxxxxxxxxxxxxxx>
Acked-by: Hans de Goede <hdegoede@xxxxxxxxxx>
Tested-by: Hans de Goede <hdegoede@xxxxxxxxxx>
Signed-off-by: Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/usb/common/roles.c | 15 ++++++++++++---
1 file 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);
--
2.19.0
