net: convert sock.sk_wmem_alloc 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/core/skbuff.c b/net/core/skbuff.c
index 659dfc0..c267713 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -3024,7 +3024,7 @@ int skb_append_datato_frags(struct sock *sk, struct sk_buff *skb,
get_page(pfrag->page);
skb->truesize += copy;
- atomic_add(copy, &sk->sk_wmem_alloc);
+ refcount_add(copy, &sk->sk_wmem_alloc);
skb->len += copy;
skb->data_len += copy;
offset += copy;