From 41c6d650f6537e55a1b53438c646fbc3f49176bf Mon Sep 17 00:00:00 2001 From: "Reshetova, Elena" Date: Fri, 30 Jun 2017 13:08:01 +0300 Subject: net: convert sock.sk_refcnt 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. This patch uses refcount_inc_not_zero() instead of atomic_inc_not_zero_hint() due to absense of a _hint() version of refcount API. If the hint() version must be used, we might need to revisit API. Signed-off-by: Elena Reshetova Signed-off-by: Hans Liljestrand Signed-off-by: Kees Cook Signed-off-by: David Windsor Signed-off-by: David S. Miller --- net/netlink/af_netlink.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'net/netlink/af_netlink.c') diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c index 8ced52e91181..5acee49db90b 100644 --- a/net/netlink/af_netlink.c +++ b/net/netlink/af_netlink.c @@ -575,7 +575,7 @@ static void netlink_remove(struct sock *sk) table = &nl_table[sk->sk_protocol]; if (!rhashtable_remove_fast(&table->hash, &nlk_sk(sk)->node, netlink_rhashtable_params)) { - WARN_ON(atomic_read(&sk->sk_refcnt) == 1); + WARN_ON(refcount_read(&sk->sk_refcnt) == 1); __sock_put(sk); } @@ -691,7 +691,7 @@ static void deferred_put_nlk_sk(struct rcu_head *head) struct netlink_sock *nlk = container_of(head, struct netlink_sock, rcu); struct sock *sk = &nlk->sk; - if (!atomic_dec_and_test(&sk->sk_refcnt)) + if (!refcount_dec_and_test(&sk->sk_refcnt)) return; if (nlk->cb_running && nlk->cb.done) { @@ -2568,7 +2568,7 @@ static int netlink_seq_show(struct seq_file *seq, void *v) sk_rmem_alloc_get(s), sk_wmem_alloc_get(s), nlk->cb_running, - atomic_read(&s->sk_refcnt), + refcount_read(&s->sk_refcnt), atomic_read(&s->sk_drops), sock_i_ino(s) ); -- cgit v1.2.1