Messages in this thread Patch in this message | | | Date | Thu, 11 Dec 2014 16:03:07 +0200 | From | Mika Westerberg <> | Subject | Re: NULL pointer dereference in i2c-hid |
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On Thu, Dec 11, 2014 at 10:58:01AM +0200, Mika Westerberg wrote: > On Wed, Dec 10, 2014 at 06:04:51PM +0100, Gabriele Mazzotta wrote: > > my laptop uses a touchpad that needs hid-rmi along with i2c-hid to work. > > i2c-hid and hid-rmi can be loaded and unloaded independelty from each > > other, however since 34f439e4afcd ("HID: i2c-hid: add runtime PM support") > > if I unload hid-rmi and after it I also unload i2c-hid, I get a NULL > > pointer dereference. > > I'll look into this. > > I can reproduce this easily with i2c-hid + hid-multitouch following your > directions.
Can you try the below patch?
I think we shouldn't free buffers yet in ->stop() because we need the command buffer sending power commands to the device. Also it seems that ->start() re-allocates buffers anyway if maximum size increases.
It shouldn't even leak memory as we release buffers at ->remove() anyway.
diff --git a/drivers/hid/i2c-hid/i2c-hid.c b/drivers/hid/i2c-hid/i2c-hid.c index 62cec01937ea..68a8c938feea 100644 --- a/drivers/hid/i2c-hid/i2c-hid.c +++ b/drivers/hid/i2c-hid/i2c-hid.c @@ -705,12 +705,7 @@ static int i2c_hid_start(struct hid_device *hid) static void i2c_hid_stop(struct hid_device *hid) { - struct i2c_client *client = hid->driver_data; - struct i2c_hid *ihid = i2c_get_clientdata(client); - hid->claimed = 0; - - i2c_hid_free_buffers(ihid); } static int i2c_hid_open(struct hid_device *hid)
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