md/raid5: cap worker count

static checker reports a potential integer overflow. Cap the worker count to avoid the overflow. Reported:-by: Dan Carpenter <[email protected]> Signed-off-by: Shaohua Li <[email protected]>
kyagi · Sep 28, 2017 · 7d5d7b5 · 7d5d7b5
1 parent c4d6a1b
commit 7d5d7b5
Showing 1 changed file with 5 additions and 2 deletions.
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
@@ -6575,14 +6575,17 @@ static ssize_t
 raid5_store_group_thread_cnt(struct mddev *mddev, const char *page, size_t len)
 {
 	struct r5conf *conf;
-	unsigned long new;
+	unsigned int new;
 	int err;
 	struct r5worker_group *new_groups, *old_groups;
 	int group_cnt, worker_cnt_per_group;
 
 	if (len >= PAGE_SIZE)
 		return -EINVAL;
-	if (kstrtoul(page, 10, &new))
+	if (kstrtouint(page, 10, &new))
+		return -EINVAL;
+	/* 8192 should be big enough */
+	if (new > 8192)
 		return -EINVAL;
 
 	err = mddev_lock(mddev);