iio:core: Fix bug in length of event info_mask and catch unhandled bi…

…ts set in masks. The unhandled bits case was highlighted by smatch: CHECK drivers/iio/industrialio-core.c drivers/iio/industrialio-core.c:719 iio_device_add_info_mask_type() error: buffer overflow 'iio_chan_info_postfix' 17 <= 31 CC [M] drivers/iio/industrialio-core.o CHECK drivers/iio/industrialio-event.c drivers/iio/industrialio-event.c:327 iio_device_add_event() error: buffer overflow 'iio_ev_info_text' 3 <= 3 The incorrect limit for the for_each_set_bit loop was noticed whilst fixing this other case. Note that as we only have 3 possible entries a the moment and the value was set to 4, the bug would not have any effect currently. It will bite fairly soon though, so best fix it now. Signed-off-by: Jonathan Cameron <[email protected]> Cc: Lars-Peter Clausen <[email protected]> Cc: Dan Carpenter <[email protected]>
zuai · Mar 16, 2014 · ef4b485 · ef4b485
1 parent 2816ac6
commit ef4b485
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Showing 2 changed files with 5 additions and 1 deletion.
diff --git a/drivers/iio/industrialio-core.c b/drivers/iio/industrialio-core.c
@@ -716,6 +716,8 @@ static int iio_device_add_info_mask_type(struct iio_dev *indio_dev,
 	int i, ret, attrcount = 0;
 
 	for_each_set_bit(i, infomask, sizeof(infomask)*8) {
+		if (i >= ARRAY_SIZE(iio_chan_info_postfix))
+			return -EINVAL;
 		ret = __iio_add_chan_devattr(iio_chan_info_postfix[i],
 					     chan,
 					     &iio_read_channel_info,

diff --git a/drivers/iio/industrialio-event.c b/drivers/iio/industrialio-event.c
@@ -321,7 +321,9 @@ 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, sizeof(*mask)*8) {
+		if (i >= ARRAY_SIZE(iio_ev_info_text))
+			return -EINVAL;
 		postfix = kasprintf(GFP_KERNEL, "%s_%s_%s",
 				iio_ev_type_text[type], iio_ev_dir_text[dir],
 				iio_ev_info_text[i]);