summaryrefslogtreecommitdiff
path: root/drivers/iio/health
diff options
context:
space:
mode:
authorJonathan Cameron <Jonathan.Cameron@huawei.com>2020-05-17 18:29:57 +0100
committerJonathan Cameron <Jonathan.Cameron@huawei.com>2020-06-14 12:32:22 +0100
commitf88ecccac4be348bbcc6d056bdbc622a8955c04d (patch)
tree7967e7b5b25117067517111153bb7bc4c09c692c /drivers/iio/health
parent3f9c6d38797e9903937b007a341dad0c251765d6 (diff)
iio:health:afe4404 Fix timestamp alignment and prevent data leak.
One of a class of bugs pointed out by Lars in a recent review. iio_push_to_buffers_with_timestamp assumes the buffer used is aligned to the size of the timestamp (8 bytes). This is not guaranteed in this driver which uses a 40 byte array of smaller elements on the stack. As Lars also noted this anti pattern can involve a leak of data to userspace and that indeed can happen here. We close both issues by moving to a suitable structure in the iio_priv() data with alignment explicitly requested. This data is allocated with kzalloc so no data can leak appart from previous readings. Fixes: 87aec56e27ef ("iio: health: Add driver for the TI AFE4404 heart monitor") Reported-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Acked-by: Andrew F. Davis <afd@ti.com> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Diffstat (limited to 'drivers/iio/health')
-rw-r--r--drivers/iio/health/afe4404.c8
1 files changed, 5 insertions, 3 deletions
diff --git a/drivers/iio/health/afe4404.c b/drivers/iio/health/afe4404.c
index e728bbb21ca8..cebb1fd4d0b1 100644
--- a/drivers/iio/health/afe4404.c
+++ b/drivers/iio/health/afe4404.c
@@ -83,6 +83,7 @@ static const struct reg_field afe4404_reg_fields[] = {
* @regulator: Pointer to the regulator for the IC
* @trig: IIO trigger for this device
* @irq: ADC_RDY line interrupt number
+ * @buffer: Used to construct a scan to push to the iio buffer.
*/
struct afe4404_data {
struct device *dev;
@@ -91,6 +92,7 @@ struct afe4404_data {
struct regulator *regulator;
struct iio_trigger *trig;
int irq;
+ s32 buffer[10] __aligned(8);
};
enum afe4404_chan_id {
@@ -328,17 +330,17 @@ static irqreturn_t afe4404_trigger_handler(int irq, void *private)
struct iio_dev *indio_dev = pf->indio_dev;
struct afe4404_data *afe = iio_priv(indio_dev);
int ret, bit, i = 0;
- s32 buffer[10];
for_each_set_bit(bit, indio_dev->active_scan_mask,
indio_dev->masklength) {
ret = regmap_read(afe->regmap, afe4404_channel_values[bit],
- &buffer[i++]);
+ &afe->buffer[i++]);
if (ret)
goto err;
}
- iio_push_to_buffers_with_timestamp(indio_dev, buffer, pf->timestamp);
+ iio_push_to_buffers_with_timestamp(indio_dev, afe->buffer,
+ pf->timestamp);
err:
iio_trigger_notify_done(indio_dev->trig);