diff mbox

[05/18] net, bluetooth: convert rfcomm_dlc.refcnt from atomic_t to refcount_t

Message ID 1489749179-12063-6-git-send-email-elena.reshetova@intel.com
State Rejected, archived
Delegated to: David Miller
Headers show

Commit Message

Reshetova, Elena March 17, 2017, 11:12 a.m. UTC 
refcount_t type and corresponding API should be
used instead of atomic_t when the variable is used as
a reference counter. This allows to avoid accidental
refcounter overflows that might lead to use-after-free
situations.

Signed-off-by: Elena Reshetova <elena.reshetova@intel.com>
Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: David Windsor <dwindsor@gmail.com>
---
 include/net/bluetooth/rfcomm.h | 8 +++++---
 net/bluetooth/rfcomm/core.c    | 4 ++--
 2 files changed, 7 insertions(+), 5 deletions(-)

Comments

Marcel Holtmann March 27, 2017, 2:05 p.m. UTC | #1 
Hi Elena,

> refcount_t type and corresponding API should be
> used instead of atomic_t when the variable is used as
> a reference counter. This allows to avoid accidental
> refcounter overflows that might lead to use-after-free
> situations.
> 
> Signed-off-by: Elena Reshetova <elena.reshetova@intel.com>
> Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com>
> Signed-off-by: Kees Cook <keescook@chromium.org>
> Signed-off-by: David Windsor <dwindsor@gmail.com>
> ---
> include/net/bluetooth/rfcomm.h | 8 +++++---
> net/bluetooth/rfcomm/core.c    | 4 ++--
> 2 files changed, 7 insertions(+), 5 deletions(-)

patch has been applied to bluetooth-next tree.

Regards

Marcel
diff mbox

Patch

diff --git a/include/net/bluetooth/rfcomm.h b/include/net/bluetooth/rfcomm.h
index 4190af5..da4acef 100644
--- a/include/net/bluetooth/rfcomm.h
+++ b/include/net/bluetooth/rfcomm.h
@@ -21,6 +21,8 @@ 
    SOFTWARE IS DISCLAIMED.
 */
 
+#include <linux/refcount.h>
+
 #ifndef __RFCOMM_H
 #define __RFCOMM_H
 
@@ -174,7 +176,7 @@  struct rfcomm_dlc {
 	struct mutex  lock;
 	unsigned long state;
 	unsigned long flags;
-	atomic_t      refcnt;
+	refcount_t    refcnt;
 	u8            dlci;
 	u8            addr;
 	u8            priority;
@@ -247,12 +249,12 @@  struct rfcomm_dlc *rfcomm_dlc_exists(bdaddr_t *src, bdaddr_t *dst, u8 channel);
 
 static inline void rfcomm_dlc_hold(struct rfcomm_dlc *d)
 {
-	atomic_inc(&d->refcnt);
+	refcount_inc(&d->refcnt);
 }
 
 static inline void rfcomm_dlc_put(struct rfcomm_dlc *d)
 {
-	if (atomic_dec_and_test(&d->refcnt))
+	if (refcount_dec_and_test(&d->refcnt))
 		rfcomm_dlc_free(d);
 }
 
diff --git a/net/bluetooth/rfcomm/core.c b/net/bluetooth/rfcomm/core.c
index f7eb02f..8ebca90 100644
--- a/net/bluetooth/rfcomm/core.c
+++ b/net/bluetooth/rfcomm/core.c
@@ -311,7 +311,7 @@  struct rfcomm_dlc *rfcomm_dlc_alloc(gfp_t prio)
 
 	skb_queue_head_init(&d->tx_queue);
 	mutex_init(&d->lock);
-	atomic_set(&d->refcnt, 1);
+	refcount_set(&d->refcnt, 1);
 
 	rfcomm_dlc_clear_state(d);
 
@@ -342,7 +342,7 @@  static void rfcomm_dlc_unlink(struct rfcomm_dlc *d)
 {
 	struct rfcomm_session *s = d->session;
 
-	BT_DBG("dlc %p refcnt %d session %p", d, atomic_read(&d->refcnt), s);
+	BT_DBG("dlc %p refcnt %d session %p", d, refcount_read(&d->refcnt), s);
 
 	list_del(&d->list);
 	d->session = NULL;