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/atm/common.c b/net/atm/common.c
index f06422f..8a4f991 100644
--- a/net/atm/common.c
+++ b/net/atm/common.c
@@ -80,9 +80,9 @@ static void vcc_sock_destruct(struct sock *sk)
printk(KERN_DEBUG "%s: rmem leakage (%d bytes) detected.\n",
__func__, atomic_read(&sk->sk_rmem_alloc));
- if (atomic_read(&sk->sk_wmem_alloc))
+ if (refcount_read(&sk->sk_wmem_alloc))
printk(KERN_DEBUG "%s: wmem leakage (%d bytes) detected.\n",
- __func__, atomic_read(&sk->sk_wmem_alloc));
+ __func__, refcount_read(&sk->sk_wmem_alloc));
}
static void vcc_def_wakeup(struct sock *sk)
@@ -101,7 +101,7 @@ static inline int vcc_writable(struct sock *sk)
struct atm_vcc *vcc = atm_sk(sk);
return (vcc->qos.txtp.max_sdu +
- atomic_read(&sk->sk_wmem_alloc)) <= sk->sk_sndbuf;
+ refcount_read(&sk->sk_wmem_alloc)) <= sk->sk_sndbuf;
}
static void vcc_write_space(struct sock *sk)
@@ -156,7 +156,7 @@ int vcc_create(struct net *net, struct socket *sock, int protocol, int family, i
memset(&vcc->local, 0, sizeof(struct sockaddr_atmsvc));
memset(&vcc->remote, 0, sizeof(struct sockaddr_atmsvc));
vcc->qos.txtp.max_sdu = 1 << 16; /* for meta VCs */
- atomic_set(&sk->sk_wmem_alloc, 1);
+ refcount_set(&sk->sk_wmem_alloc, 1);
atomic_set(&sk->sk_rmem_alloc, 0);
vcc->push = NULL;
vcc->pop = NULL;
@@ -630,7 +630,7 @@ int vcc_sendmsg(struct socket *sock, struct msghdr *m, size_t size)
goto out;
}
pr_debug("%d += %d\n", sk_wmem_alloc_get(sk), skb->truesize);
- atomic_add(skb->truesize, &sk->sk_wmem_alloc);
+ refcount_add(skb->truesize, &sk->sk_wmem_alloc);
skb->dev = NULL; /* for paths shared with net_device interfaces */
ATM_SKB(skb)->atm_options = vcc->atm_options;