[PATCH] 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>
---
 drivers/watchdog/aspeed_wdt.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/drivers/watchdog/aspeed_wdt.c b/drivers/watchdog/aspeed_wdt.c
index 7e00960651fa..9f77272dc906 100644
--- a/drivers/watchdog/aspeed_wdt.c
+++ b/drivers/watchdog/aspeed_wdt.c
@@ -145,9 +145,8 @@ static int aspeed_wdt_set_timeout(struct watchdog_device *wdd,
 	struct aspeed_wdt *wdt = to_aspeed_wdt(wdd);
 	u32 actual;
 
-	wdd->timeout = timeout;
-
-	actual = min(timeout, wdd->max_hw_heartbeat_ms * 1000);
+	actual = min(timeout, wdd->max_hw_heartbeat_ms / 1000);
+	wdd->timeout = actual;
 
 	writel(actual * WDT_RATE_1MHZ, wdt->base + WDT_RELOAD_VALUE);
 	writel(WDT_RESTART_MAGIC, wdt->base + WDT_RESTART);
-- 
2.17.1