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/packet/af_packet.c b/net/packet/af_packet.c
index f9349a4..90fd38d 100644
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -1317,7 +1317,7 @@ static void packet_sock_destruct(struct sock *sk)
skb_queue_purge(&sk->sk_error_queue);
WARN_ON(atomic_read(&sk->sk_rmem_alloc));
- WARN_ON(atomic_read(&sk->sk_wmem_alloc));
+ WARN_ON(refcount_read(&sk->sk_wmem_alloc));
if (!sock_flag(sk, SOCK_DEAD)) {
pr_err("Attempt to release alive packet socket: %p\n", sk);
@@ -2523,7 +2523,7 @@ static int tpacket_fill_skb(struct packet_sock *po, struct sk_buff *skb,
skb->data_len = to_write;
skb->len += to_write;
skb->truesize += to_write;
- atomic_add(to_write, &po->sk.sk_wmem_alloc);
+ refcount_add(to_write, &po->sk.sk_wmem_alloc);
while (likely(to_write)) {
nr_frags = skb_shinfo(skb)->nr_frags;
