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authorReshetova, Elena <elena.reshetova@intel.com>2017-07-04 15:53:08 +0300
committerDavid S. Miller <davem@davemloft.net>2017-07-04 22:35:16 +0100
commit0408c58be5a475c99b271f08d85859f7b59ec767 (patch)
tree100c31c9fab2ae3b9fee699c83fa798cfbb0baad
parent7b9364050246bd4c24b36b71c8990b2922dcc027 (diff)
net, lapb: convert lapb_cb.refcnt from atomic_t to refcount_t
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> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--include/net/lapb.h3
-rw-r--r--net/lapb/lapb_iface.c6
2 files changed, 5 insertions, 4 deletions
diff --git a/include/net/lapb.h b/include/net/lapb.h
index 9510f8725f03..85e773742f4e 100644
--- a/include/net/lapb.h
+++ b/include/net/lapb.h
@@ -1,6 +1,7 @@
#ifndef _LAPB_H
#define _LAPB_H
#include <linux/lapb.h>
+#include <linux/refcount.h>
#define LAPB_HEADER_LEN 20 /* LAPB over Ethernet + a bit more */
@@ -101,7 +102,7 @@ struct lapb_cb {
struct lapb_frame frmr_data;
unsigned char frmr_type;
- atomic_t refcnt;
+ refcount_t refcnt;
};
/* lapb_iface.c */
diff --git a/net/lapb/lapb_iface.c b/net/lapb/lapb_iface.c
index b50b64ac8815..e15314e3b464 100644
--- a/net/lapb/lapb_iface.c
+++ b/net/lapb/lapb_iface.c
@@ -54,12 +54,12 @@ static void lapb_free_cb(struct lapb_cb *lapb)
static __inline__ void lapb_hold(struct lapb_cb *lapb)
{
- atomic_inc(&lapb->refcnt);
+ refcount_inc(&lapb->refcnt);
}
static __inline__ void lapb_put(struct lapb_cb *lapb)
{
- if (atomic_dec_and_test(&lapb->refcnt))
+ if (refcount_dec_and_test(&lapb->refcnt))
lapb_free_cb(lapb);
}
@@ -136,7 +136,7 @@ static struct lapb_cb *lapb_create_cb(void)
lapb->mode = LAPB_DEFAULT_MODE;
lapb->window = LAPB_DEFAULT_WINDOW;
lapb->state = LAPB_STATE_0;
- atomic_set(&lapb->refcnt, 1);
+ refcount_set(&lapb->refcnt, 1);
out:
return lapb;
}