gpio: pca953x: Fix dereference of irq data in shutdown
authorMark Walton <mark.walton@serialtek.com>
Thu, 28 Feb 2019 15:46:36 +0000 (15:46 +0000)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Sat, 23 Mar 2019 19:10:05 +0000 (20:10 +0100)
commit6f29e4c2dbb1d8fc3f636e79c41492d6b0e5cae1
tree24152b1c8bb011db199167d69412734b03c8327c
parente86a57ecdfac68330a19a87bdb995acc31898cbb
gpio: pca953x: Fix dereference of irq data in shutdown

commit c378b3aa015931a46c91d6ccc2fe04d97801d060 upstream.

If a PCA953x gpio was used as an interrupt and then released,
the shutdown function was trying to extract the pca953x_chip
pointer directly from the irq_data, but in reality was getting
the gpio_chip structure.

The net effect was that the subsequent writes to the data
structure corrupted data in the gpio_chip structure, which wasn't
immediately obvious until attempting to use the GPIO again in the
future, at which point the kernel panics.

This fix correctly extracts the pca953x_chip structure via the
gpio_chip structure, as is correctly done in the other irq
functions.

Fixes: 0a70fe00efea ("gpio: pca953x: Clear irq trigger type on irq shutdown")
Cc: stable@vger.kernel.org
Signed-off-by: Mark Walton <mark.walton@serialtek.com>
Reviewed-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/gpio/gpio-pca953x.c