iio: light: bh1745: fix information leak in triggered buffer

commit b62fbe3b8eedd3cf3c9ad0b7cb9f72c3f40815f0 upstream.

The 'scan' local struct is used to push data to user space from a
triggered buffer, but it does not set values for inactive channels, as
it only uses iio_for_each_active_channel() to assign new values.

Initialize the struct to zero before using it to avoid pushing
uninitialized information to userspace.

Cc: stable@vger.kernel.org
Fixes: eab35358aae7 ("iio: light: ROHM BH1745 colour sensor")
Signed-off-by: Javier Carrasco <javier.carrasco.cruz@gmail.com>
Link: https://patch.msgid.link/20241125-iio_memset_scan_holes-v1-7-0cb6e98d895c@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/iio/light/bh1745.c b/drivers/iio/light/bh1745.c
index 2e458e9d5d85308fb6a13d9dbd845fa03b56a40e..a025e279df0747574780901d1a0d1ffa4ce5494e 100644 (file)
--- a/drivers/iio/light/bh1745.c
+++ b/drivers/iio/light/bh1745.c
@@ -750,6 +750,8 @@ static irqreturn_t bh1745_trigger_handler(int interrupt, void *p)
        int i;
        int j = 0;
 
+       memset(&scan, 0, sizeof(scan));
+
        iio_for_each_active_channel(indio_dev, i) {
                ret = regmap_bulk_read(data->regmap, BH1745_RED_LSB + 2 * i,
                                       &value, 2);