[PATCH 3.16 04/72] leds: leds-lp5562 allow firmware files up to the maximum length

Ben Hutchings
2019-12-08T13:59:24Z

From: Nick Stoughton <nstoughton@logitech.com>

commit ed2abfebb041473092b41527903f93390d38afa7 upstream.

Firmware files are in ASCII, using 2 hex characters per byte. The
maximum length of a firmware string is therefore

16 (commands) * 2 (bytes per command) * 2 (characters per byte) = 64

Fixes: ff45262a85db ("leds: add new LP5562 LED driver")
Signed-off-by: Nick Stoughton <nstoughton@logitech.com>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Jacek Anaszewski <jacek.anaszewski@gmail.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
drivers/leds/leds-lp5562.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)

--- a/drivers/leds/leds-lp5562.c
+++ b/drivers/leds/leds-lp5562.c
@@ -263,7 +263,11 @@ static void lp5562_firmware_loaded(struc
{
const struct firmware *fw = chip->fw;

- if (fw->size > LP5562_PROGRAM_LENGTH) {
+ /*
+ * the firmware is encoded in ascii hex character, with 2 chars
+ * per byte
+ */
+ if (fw->size > (LP5562_PROGRAM_LENGTH * 2)) {
dev_err(&chip->cl->dev, "firmware data size overflow: %zu\n",
fw->size);
return;