[PATCH 14/21] leds: flash: Avoid divide-by-zero in led_clamp_align()

[Lee Jones]

If a flash LED driver leaves a setting's step size as zero, writing to
the corresponding sysfs attribute invokes led_clamp_align() and triggers
an integer division by zero when aligning the offset to s->step.

Clamp s->val to [s->min, s->max] and return early when s->step is zero.

Fixes: 7aea8389a77a ("leds: Add LED Flash class extension to the LED subsystem")
Closes: https://sashiko.dev/#/bug/linux-9d06d7fe-310b-4aee-8b16-0fb49550c287
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Lee Jones <lee@xxxxxxxxxx>
---
 drivers/leds/led-class-flash.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/leds/led-class-flash.c b/drivers/leds/led-class-flash.c
index 181dfd49c6ad..16b3b6b9365b 100644
--- a/drivers/leds/led-class-flash.c
+++ b/drivers/leds/led-class-flash.c
@@ -375,6 +375,11 @@ static void led_clamp_align(struct led_flash_setting *s)
 {
 	u32 v, offset;
 
+	if (!s->step) {
+		s->val = clamp(s->val, s->min, s->max);
+		return;
+	}
+
 	v = s->val + s->step / 2;
 	v = clamp(v, s->min, s->max);
 	offset = v - s->min;
-- 
2.56.0.218.g1ec904b173-goog