From a506aedc51093544ff0f9610af6066d18cb6abbe Mon Sep 17 00:00:00 2001
From: "wzt.wzt@gmail.com" <wzt.wzt@gmail.com>
Date: Fri, 2 Apr 2010 08:41:14 +0200
Subject: [PATCH] Block: Fix block/elevator.c elevator_get() off-by-one error
elevator_get() not check the name length, if the name length > sizeof(elv),
elv will miss the '\0'. And elv buffer will be replace "-iosched" as something
like aaaaaaaaa, then call request_module() can load an not trust module.
Signed-off-by: Zhitong Wang <zhitong.wangzt@alibaba-inc.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
---
block/elevator.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/block/elevator.c b/block/elevator.c
index df75676f6671..76e3702d5381 100644
--- a/block/elevator.c
+++ b/block/elevator.c
@@ -154,7 +154,7 @@ static struct elevator_type *elevator_get(const char *name)
spin_unlock(&elv_list_lock);
- sprintf(elv, "%s-iosched", name);
+ snprintf(elv, sizeof(elv), "%s-iosched", name);
request_module("%s", elv);
spin_lock(&elv_list_lock);