net: convert packet_fanout.sk_ref 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>
diff --git a/net/packet/internal.h b/net/packet/internal.h
index 9ee4631..94d1d40 100644
--- a/net/packet/internal.h
+++ b/net/packet/internal.h
@@ -1,6 +1,8 @@
#ifndef __PACKET_INTERNAL_H__
#define __PACKET_INTERNAL_H__
+#include <linux/refcount.h>
+
struct packet_mclist {
struct packet_mclist *next;
int ifindex;
@@ -86,7 +88,7 @@ struct packet_fanout {
struct list_head list;
struct sock *arr[PACKET_FANOUT_MAX];
spinlock_t lock;
- atomic_t sk_ref;
+ refcount_t sk_ref;
struct packet_type prot_hook ____cacheline_aligned_in_smp;
};
