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>
This commit is contained in:
Reshetova, Elena
2017-06-30 13:08:00 +03:00
committed by David S. Miller
parent 2638595afc
commit 14afee4b60
37 changed files with 74 additions and 85 deletions

View File

@@ -442,7 +442,7 @@ static int unix_dgram_peer_wake_me(struct sock *sk, struct sock *other)
static int unix_writable(const struct sock *sk)
{
return sk->sk_state != TCP_LISTEN &&
(atomic_read(&sk->sk_wmem_alloc) << 2) <= sk->sk_sndbuf;
(refcount_read(&sk->sk_wmem_alloc) << 2) <= sk->sk_sndbuf;
}
static void unix_write_space(struct sock *sk)
@@ -487,7 +487,7 @@ static void unix_sock_destructor(struct sock *sk)
skb_queue_purge(&sk->sk_receive_queue);
WARN_ON(atomic_read(&sk->sk_wmem_alloc));
WARN_ON(refcount_read(&sk->sk_wmem_alloc));
WARN_ON(!sk_unhashed(sk));
WARN_ON(sk->sk_socket);
if (!sock_flag(sk, SOCK_DEAD)) {
@@ -2033,7 +2033,7 @@ alloc_skb:
skb->len += size;
skb->data_len += size;
skb->truesize += size;
atomic_add(size, &sk->sk_wmem_alloc);
refcount_add(size, &sk->sk_wmem_alloc);
if (newskb) {
err = unix_scm_to_skb(&scm, skb, false);