From 3fff22743640637c2b61473d3cc8d7dc2215984f Mon Sep 17 00:00:00 2001 From: Lars-Peter Clausen Date: Wed, 12 Sep 2012 12:06:00 +0100 Subject: staging:iio:dummy: Fix potential NULL pointer dereference If the config contains CONFIG_IIO_BUFFER=y and CONFIG_IIO_SIMPLE_DUMMY_BUFFER=n iio_simple_dummy_configure_buffer() is stubbed out and iio_buffer_register() is not. As a result we try to register a buffer which has not been configured. This will causes a NULL pointer deref in iio_buffer_register. To solve this issue move the iio_buffer_register() call to iio_simple_dummy_configure_buffer(), so it will only be called if iio_simple_dummy_configure_buffer() has been called. Reported-by: Fengguang Wu Signed-off-by: Lars-Peter Clausen Signed-off-by: Jonathan Cameron --- drivers/staging/iio/iio_simple_dummy.c | 20 +++++++------------- 1 file changed, 7 insertions(+), 13 deletions(-) (limited to 'drivers/staging/iio/iio_simple_dummy.c') diff --git a/drivers/staging/iio/iio_simple_dummy.c b/drivers/staging/iio/iio_simple_dummy.c index 029bcc67f164..dc6c728ea47a 100644 --- a/drivers/staging/iio/iio_simple_dummy.c +++ b/drivers/staging/iio/iio_simple_dummy.c @@ -445,26 +445,20 @@ static int __devinit iio_dummy_probe(int index) if (ret < 0) goto error_free_device; - /* Configure buffered capture support. */ - ret = iio_simple_dummy_configure_buffer(indio_dev); - if (ret < 0) - goto error_unregister_events; - /* - * Register the channels with the buffer, but avoid the output - * channel being registered by reducing the number of channels by 1. + * Configure buffered capture support and register the channels with the + * buffer, but avoid the output channel being registered by reducing the + * number of channels by 1. */ - ret = iio_buffer_register(indio_dev, iio_dummy_channels, 5); + ret = iio_simple_dummy_configure_buffer(indio_dev, iio_dummy_channels, 5); if (ret < 0) - goto error_unconfigure_buffer; + goto error_unregister_events; ret = iio_device_register(indio_dev); if (ret < 0) - goto error_unregister_buffer; + goto error_unconfigure_buffer; return 0; -error_unregister_buffer: - iio_buffer_unregister(indio_dev); error_unconfigure_buffer: iio_simple_dummy_unconfigure_buffer(indio_dev); error_unregister_events: @@ -499,7 +493,6 @@ static int iio_dummy_remove(int index) /* Device specific code to power down etc */ /* Buffered capture related cleanup */ - iio_buffer_unregister(indio_dev); iio_simple_dummy_unconfigure_buffer(indio_dev); ret = iio_simple_dummy_events_unregister(indio_dev); @@ -530,6 +523,7 @@ static __init int iio_dummy_init(void) instances = 1; return -EINVAL; } + /* Fake a bus */ iio_dummy_devs = kcalloc(instances, sizeof(*iio_dummy_devs), GFP_KERNEL); -- cgit v1.2.3