4.9-stable review patch. If anyone has any objections, please let me know.
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From: Krzysztof Kozlowski krzk@kernel.org
commit 2ea8bab4dd2a9014e723b28091831fa850b82d83 upstream.
Fix NULL pointer exception on device unbind when device tree does not contain "has-touchscreen" property. In such case the input device is not registered so it should not be unregistered.
$ echo "12d10000.adc" > /sys/bus/platform/drivers/exynos-adc/unbind
Unable to handle kernel NULL pointer dereference at virtual address 00000474 ... (input_unregister_device) from [<c0772060>] (exynos_adc_remove+0x20/0x80) (exynos_adc_remove) from [<c0587d5c>] (platform_drv_remove+0x20/0x40) (platform_drv_remove) from [<c05860f0>] (device_release_driver_internal+0xdc/0x1ac) (device_release_driver_internal) from [<c0583ecc>] (unbind_store+0x60/0xd4) (unbind_store) from [<c031b89c>] (kernfs_fop_write+0x100/0x1e0) (kernfs_fop_write) from [<c029709c>] (__vfs_write+0x2c/0x17c) (__vfs_write) from [<c0297374>] (vfs_write+0xa4/0x184) (vfs_write) from [<c0297594>] (ksys_write+0x4c/0xac) (ksys_write) from [<c0101000>] (ret_fast_syscall+0x0/0x28)
Fixes: 2bb8ad9b44c5 ("iio: exynos-adc: add experimental touchscreen support") Cc: stable@vger.kernel.org Signed-off-by: Krzysztof Kozlowski krzk@kernel.org Signed-off-by: Jonathan Cameron Jonathan.Cameron@huawei.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/iio/adc/exynos_adc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/drivers/iio/adc/exynos_adc.c +++ b/drivers/iio/adc/exynos_adc.c @@ -916,7 +916,7 @@ static int exynos_adc_remove(struct plat struct iio_dev *indio_dev = platform_get_drvdata(pdev); struct exynos_adc *info = iio_priv(indio_dev);
- if (IS_REACHABLE(CONFIG_INPUT)) { + if (IS_REACHABLE(CONFIG_INPUT) && info->input) { free_irq(info->tsirq, info); input_unregister_device(info->input); }