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authorLars-Peter Clausen <lars@metafoo.de>2012-06-15 20:08:59 +0400
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2012-06-16 01:39:19 +0400
commitaff1eb4e3dd13ee419c6cd76baf1bcc2edeaaa86 (patch)
tree36fbc70e56ffa72bcb33067a178981cb9f841b82 /drivers/iio
parentfb1c4bcd721fcc30d6e43f60a244483dc0d07056 (diff)
downloadlinux-aff1eb4e3dd13ee419c6cd76baf1bcc2edeaaa86.tar.xz
iio: buffer: Fix NULL pointer deref caused by empty scan mask
iio_scan_mask_match() returns NULL if the passed in scan mask is empty. This will happen if no channel has been selected and buffer is enabled. iio_sw_buffer_preenable() will assign NULL to indio_dev->active_scan_mask in this case. As a result iio_update_demux() will cause a NULL pointer deref, because it expects active_scan_mask to be non-NULL. Since it does not make much sense to start data capture if there is no data to capture this patch updates the code to fail gracefully in iio_scan_mask_match() instead of crashing the kernel. Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Acked-by: Jonathan Cameron <jic23@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/iio')
-rw-r--r--drivers/iio/industrialio-buffer.c4
1 files changed, 4 insertions, 0 deletions
diff --git a/drivers/iio/industrialio-buffer.c b/drivers/iio/industrialio-buffer.c
index ac185b8694bd..2f35db93cdb6 100644
--- a/drivers/iio/industrialio-buffer.c
+++ b/drivers/iio/industrialio-buffer.c
@@ -553,6 +553,10 @@ int iio_sw_buffer_preenable(struct iio_dev *indio_dev)
buffer->scan_mask);
else
indio_dev->active_scan_mask = buffer->scan_mask;
+
+ if (indio_dev->active_scan_mask == NULL)
+ return -EINVAL;
+
iio_update_demux(indio_dev);
if (indio_dev->info->update_scan_mode)