diff options
author | Elena Reshetova <elena.reshetova@intel.com> | 2017-10-20 10:23:49 +0300 |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2017-10-22 04:22:39 +0300 |
commit | e65f7ee39b4d7604a78b03ed35d723e1001fc241 (patch) | |
tree | 047ba8c6ba1f159c9339923ca939dbb2d81c5897 /include/linux/connector.h | |
parent | 709c89b45b874b2f81a074b8802a736009873f48 (diff) | |
download | linux-e65f7ee39b4d7604a78b03ed35d723e1001fc241.tar.xz |
drivers, connector: convert cn_callback_entry.refcnt from atomic_t to refcount_t
atomic_t variables are currently used to implement reference
counters with the following properties:
- counter is initialized to 1 using atomic_set()
- a resource is freed upon counter reaching zero
- once counter reaches zero, its further
increments aren't allowed
- counter schema uses basic atomic operations
(set, inc, inc_not_zero, dec_and_test, etc.)
Such atomic variables should be converted to a newly provided
refcount_t type and API that prevents accidental counter overflows
and underflows. This is important since overflows and underflows
can lead to use-after-free situation and be exploitable.
The variable cn_callback_entry.refcnt is used as pure reference counter.
Convert it to refcount_t and fix up the operations.
Suggested-by: Kees Cook <keescook@chromium.org>
Reviewed-by: David Windsor <dwindsor@gmail.com>
Reviewed-by: Hans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: Elena Reshetova <elena.reshetova@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include/linux/connector.h')
-rw-r--r-- | include/linux/connector.h | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/include/linux/connector.h b/include/linux/connector.h index f8fe8637d771..032102b19645 100644 --- a/include/linux/connector.h +++ b/include/linux/connector.h @@ -22,7 +22,7 @@ #define __CONNECTOR_H -#include <linux/atomic.h> +#include <linux/refcount.h> #include <linux/list.h> #include <linux/workqueue.h> @@ -49,7 +49,7 @@ struct cn_callback_id { struct cn_callback_entry { struct list_head callback_entry; - atomic_t refcnt; + refcount_t refcnt; struct cn_queue_dev *pdev; struct cn_callback_id id; |