Messages in this thread | | | Date | Wed, 8 Oct 2014 14:40:45 -0700 | From | Dmitry Torokhov <> | Subject | Re: [PATCH v2] HID: wacom: Prevent potential null dereference after disconnect |
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On Wed, Oct 08, 2014 at 11:25:42AM -0700, Jason Gerecke wrote: > Repeated connect/disconnect cycles under GNOME can trigger an occasional > OOPS from within e.g. wacom_led_select_store, presumably due to a timing > issue where userspace begins setting a value immediately before the > device disconnects and our shared data is whisked away. > > Signed-off-by: Jason Gerecke <killertofu@gmail.com> > --- > Changes in v2: > * Added in missing escape character > > drivers/hid/wacom_sys.c | 13 ++++++++++++- > 1 file changed, 12 insertions(+), 1 deletion(-) > > diff --git a/drivers/hid/wacom_sys.c b/drivers/hid/wacom_sys.c > index 8593047..265429b 100644 > --- a/drivers/hid/wacom_sys.c > +++ b/drivers/hid/wacom_sys.c > @@ -641,6 +641,9 @@ static ssize_t wacom_led_select_store(struct device *dev, int set_id, > unsigned int id; > int err; > > + if (!wacom) > + return -ENODEV; > +
Strong NAK. If device could disappear before this check it could as well disappear after your check.
This patch does not solve anything.
> err = kstrtouint(buf, 10, &id); > if (err) > return err;
Thanks.
-- Dmitry
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