[PATCH 2/2] iio: fix possible buffer overflow

[Alexandre Belloni <alexandre.belloni@free-electrons.com>]

Found using smatch:
drivers/iio/industrialio-event.c:327 iio_device_add_event() error: buffer
overflow 'iio_ev_info_text' 3 <= 7

It was probably never hit because the mask_* members of the event_spec struct
are filled by using the BIT() macro with values from the iio_event_info enum
that also serve as the index of the iio_ev_info_text array.

Also, for_each_set_bit takes a number of bits as the size, not a number of
bytes.

Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
---
 drivers/iio/industrialio-event.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/iio/industrialio-event.c b/drivers/iio/industrialio-event.c
index ea6e06b9c7d4..804e90676159 100644
--- a/drivers/iio/industrialio-event.c
+++ b/drivers/iio/industrialio-event.c
@@ -321,7 +321,8 @@ static int iio_device_add_event(struct iio_dev *indio_dev,
 	char *postfix;
 	int ret;
 
-	for_each_set_bit(i, mask, sizeof(*mask)) {
+	for_each_set_bit(i, mask,
+			 min(sizeof(*mask)*8, ARRAY_SIZE(iio_ev_info_text))) {
 		postfix = kasprintf(GFP_KERNEL, "%s_%s_%s",
 				iio_ev_type_text[type], iio_ev_dir_text[dir],
 				iio_ev_info_text[i]);
-- 
1.9.1