[PATCH v2] watchdog: aspeed: fix integer overflow in set_timeout handler

[rentao.bupt at gmail.com]

From: Tao Ren <rentao.bupt at gmail.com>

Fix the time comparison (timeout vs. max_hw_heartbeat_ms) in set_timeout
handler to avoid potential integer overflow when the supplied timeout is
greater than aspeed's maximum allowed timeout (4294 seconds).

Fixes: efa859f7d786 ("watchdog: Add Aspeed watchdog driver")
Reported-by: Amithash Prasad <amithash at fb.com>
Signed-off-by: Tao Ren <rentao.bupt at gmail.com>
---
 Changes in v2:
   - do not touch "wdd->timeout": only "max_hw_heartbeat_ms * 1000" is
     updated to "max_hw_heartbeat_ms / 1000".

 drivers/watchdog/aspeed_wdt.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/watchdog/aspeed_wdt.c b/drivers/watchdog/aspeed_wdt.c
index 7e00960651fa..507fd815d767 100644
--- a/drivers/watchdog/aspeed_wdt.c
+++ b/drivers/watchdog/aspeed_wdt.c
@@ -147,7 +147,7 @@ static int aspeed_wdt_set_timeout(struct watchdog_device *wdd,
 
 	wdd->timeout = timeout;
 
-	actual = min(timeout, wdd->max_hw_heartbeat_ms * 1000);
+	actual = min(timeout, wdd->max_hw_heartbeat_ms / 1000);
 
 	writel(actual * WDT_RATE_1MHZ, wdt->base + WDT_RELOAD_VALUE);
 	writel(WDT_RESTART_MAGIC, wdt->base + WDT_RESTART);
-- 
2.17.1