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@xxxxxxxxx>
Signed-off-by: Hans Liljestrand <ishkamiel@xxxxxxxxx>
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
Signed-off-by: David Windsor <dwindsor@xxxxxxxxx>
---
include/net/bluetooth/rfcomm.h | 8 +++++---
net/bluetooth/rfcomm/core.c | 4 ++--
2 files changed, 7 insertions(+), 5 deletions(-)
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;
--
2.7.4
--
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