drivers/gpio/gpiolib-cdev.c | 193 ++++++++++++++++++++++++++++++++---- drivers/gpio/gpiolib.c | 4 + drivers/gpio/gpiolib.h | 5 + 3 files changed, 180 insertions(+), 22 deletions(-)
From: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
This is (hopefully) the final iteration of the changes that aim at fixing
the situation in which the user-space can provoke a NULL-pointer derefence
in the kernel when a GPIO device that's in use by user-space is removed.
v5 -> v6:
- signal an error in poll callbacks instead of returning 0 which would make
the user-space assume a timeout occurred (which could lead to user-space
spinning a timeout loop forever)
v4 -> v5:
- try to acquire the semaphore for reading and bail out of syscall callbacks
immediately in case of lock contention
v3 -> v4:
- use function typedefs to make code cleaner
- add a blank line after down_write()
v2 -> v3:
- drop the helper variable in patch 1/2 as we won't be using it in 2/2
- refactor patch 2/2 to use locking wrappers around the syscall callbacks
v1 -> v2:
- add missing gdev->chip checks in patch 1/2
- add a second patch that protects the structures that can be accessed
by user-space calls against concurrent removal
Bartosz Golaszewski (2):
gpiolib: cdev: fix NULL-pointer dereferences
gpiolib: protect the GPIO device against being dropped while in use by
user-space
drivers/gpio/gpiolib-cdev.c | 193 ++++++++++++++++++++++++++++++++----
drivers/gpio/gpiolib.c | 4 +
drivers/gpio/gpiolib.h | 5 +
3 files changed, 180 insertions(+), 22 deletions(-)
--
2.37.2
On Thu, Dec 1, 2022 at 1:59 PM Bartosz Golaszewski <brgl@bgdev.pl> wrote: > > From: Bartosz Golaszewski <bartosz.golaszewski@linaro.org> > > This is (hopefully) the final iteration of the changes that aim at fixing > the situation in which the user-space can provoke a NULL-pointer derefence > in the kernel when a GPIO device that's in use by user-space is removed. > > v5 -> v6: > - signal an error in poll callbacks instead of returning 0 which would make > the user-space assume a timeout occurred (which could lead to user-space > spinning a timeout loop forever) > > v4 -> v5: > - try to acquire the semaphore for reading and bail out of syscall callbacks > immediately in case of lock contention > > v3 -> v4: > - use function typedefs to make code cleaner > - add a blank line after down_write() > > v2 -> v3: > - drop the helper variable in patch 1/2 as we won't be using it in 2/2 > - refactor patch 2/2 to use locking wrappers around the syscall callbacks > > v1 -> v2: > - add missing gdev->chip checks in patch 1/2 > - add a second patch that protects the structures that can be accessed > by user-space calls against concurrent removal > > Bartosz Golaszewski (2): > gpiolib: cdev: fix NULL-pointer dereferences > gpiolib: protect the GPIO device against being dropped while in use by > user-space > > drivers/gpio/gpiolib-cdev.c | 193 ++++++++++++++++++++++++++++++++---- > drivers/gpio/gpiolib.c | 4 + > drivers/gpio/gpiolib.h | 5 + > 3 files changed, 180 insertions(+), 22 deletions(-) > > -- > 2.37.2 > I know Kent and Linus left their review tags already, I will add them when applying. Bart
On Thu, Dec 01, 2022 at 02:00:06PM +0100, Bartosz Golaszewski wrote: > On Thu, Dec 1, 2022 at 1:59 PM Bartosz Golaszewski <brgl@bgdev.pl> wrote: ... > I know Kent and Linus left their review tags already, I will add them > when applying. I guess it's good enough, go ahead with it. -- With Best Regards, Andy Shevchenko
On Thu, Dec 1, 2022 at 2:59 PM Andy Shevchenko <andriy.shevchenko@linux.intel.com> wrote: > > On Thu, Dec 01, 2022 at 02:00:06PM +0100, Bartosz Golaszewski wrote: > > On Thu, Dec 1, 2022 at 1:59 PM Bartosz Golaszewski <brgl@bgdev.pl> wrote: > > ... > > > I know Kent and Linus left their review tags already, I will add them > > when applying. > > I guess it's good enough, go ahead with it. > > -- > With Best Regards, > Andy Shevchenko > > Can you leave your Reviewed-by here too? Bart
On Thu, Dec 01, 2022 at 03:13:55PM +0100, Bartosz Golaszewski wrote: > On Thu, Dec 1, 2022 at 2:59 PM Andy Shevchenko > <andriy.shevchenko@linux.intel.com> wrote: > > > > On Thu, Dec 01, 2022 at 02:00:06PM +0100, Bartosz Golaszewski wrote: > > > On Thu, Dec 1, 2022 at 1:59 PM Bartosz Golaszewski <brgl@bgdev.pl> wrote: > > > > ... > > > > > I know Kent and Linus left their review tags already, I will add them > > > when applying. > > > > I guess it's good enough, go ahead with it. > > Can you leave your Reviewed-by here too? Hmm... Your both patches already have it. -- With Best Regards, Andy Shevchenko
On Thu, Dec 1, 2022 at 4:40 PM Andy Shevchenko <andriy.shevchenko@linux.intel.com> wrote: > > On Thu, Dec 01, 2022 at 03:13:55PM +0100, Bartosz Golaszewski wrote: > > On Thu, Dec 1, 2022 at 2:59 PM Andy Shevchenko > > <andriy.shevchenko@linux.intel.com> wrote: > > > > > > On Thu, Dec 01, 2022 at 02:00:06PM +0100, Bartosz Golaszewski wrote: > > > > On Thu, Dec 1, 2022 at 1:59 PM Bartosz Golaszewski <brgl@bgdev.pl> wrote: > > > > > > ... > > > > > > > I know Kent and Linus left their review tags already, I will add them > > > > when applying. > > > > > > I guess it's good enough, go ahead with it. > > > > Can you leave your Reviewed-by here too? > > Hmm... Your both patches already have it. > > -- > With Best Regards, > Andy Shevchenko > > I was thinking about the mailing list's history but whatever. Applying it now. Bart
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