Messages in this thread | | | Date | Fri, 25 Nov 2022 19:56:09 +0200 | From | Andy Shevchenko <> | Subject | Re: [PATCH] gpiolib: cdev: fix NULL-pointer dereferences |
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On Fri, Nov 25, 2022 at 05:48:02PM +0100, Bartosz Golaszewski wrote: > On Fri, Nov 25, 2022 at 5:24 PM Kent Gibson <warthog618@gmail.com> wrote:
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> Then at the subsystem level, the GPIO device struct would need a lock > that would be taken by every user-space operation AND the code > unregistering the device so that we don't do what you described (i.e. > if there's a thread doing a read(), then let's wait until it returns > before we drop the device).
It's called a reference counting, basically you need to get device and then put when it makes sense.
> This wouldn't fix the case in which the same situation happened in a > kernel driver but crashing the kernel from within is a much lesser > offense than allowing user-space to crash it.
-- With Best Regards, Andy Shevchenko
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