Messages in this thread | | | Date | Sun, 15 Jul 2018 09:42:25 +0200 | From | Marcus Folkesson <> | Subject | Re: [PATCH] Input: pxrc - fix leak of usb_device |
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On Sat, Jul 14, 2018 at 08:51:09AM +0000, Dmitry Torokhov wrote: > On Sat, Jul 14, 2018 at 10:09:20AM +0200, Marcus Folkesson wrote: > > Hi Alexey, > > > > Good catch! > > > > On Fri, Jul 13, 2018 at 11:07:57PM +0300, Alexey Khoroshilov wrote: > > > pxrc_probe() calls usb_get_dev(), but there is no usb_put_dev() > > > anywhere in the driver. > > > > > > The patch adds one to error handling code and to pxrc_disconnect(). > > > > > > Found by Linux Driver Verification project (linuxtesting.org). > > > > > > Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru> > > > > Reviewed-by: Marcus Folkesson <marcus.folkesson@gmail.com> > > Hmm, the biggest question however if we need to "take" the device, as I > do not think interface can outlive the device, and whether we actually > need to store it in pxrc, as we only need it during set up, as far as I > can see.
Yep, the device is only used during setup. I interpret the comments for usb_get_dev() as you should take a reference count on the device even if you only use the interface, but I could be wrong.
From usb_get_dev()::
* usb_get_dev - increments the reference count of the usb device structure * @dev: the device being referenced * * Each live reference to a device should be refcounted. * * Drivers for USB interfaces should normally record such references in * their probe() methods, when they bind to an interface, and release * them by calling usb_put_dev(), in their disconnect() methods.
I can fix the driver to not take the device if that is what we want. If not Alexey want to fix it of course, it is his catch :-)
> > Thanks. > > -- > Dmitry
Best regards Marcus Folkesson
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