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/core/skbuff.c | 6 +++--- net/core/sock.c | 6 +++--- 2 files changed, 6 insertions(+), 6 deletions(-) (limited to 'net/core') diff --git a/net/core/skbuff.c b/net/core/skbuff.c index c267713cd383..8b11341ed69a 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -3844,7 +3844,7 @@ struct sk_buff *skb_clone_sk(struct sk_buff *skb) struct sock *sk = skb->sk; struct sk_buff *clone; - if (!sk || !atomic_inc_not_zero(&sk->sk_refcnt)) + if (!sk || !refcount_inc_not_zero(&sk->sk_refcnt)) return NULL; clone = skb_clone(skb, GFP_ATOMIC); @@ -3915,7 +3915,7 @@ void skb_complete_tx_timestamp(struct sk_buff *skb, /* Take a reference to prevent skb_orphan() from freeing the socket, * but only if the socket refcount is not zero. */ - if (likely(atomic_inc_not_zero(&sk->sk_refcnt))) { + if (likely(refcount_inc_not_zero(&sk->sk_refcnt))) { *skb_hwtstamps(skb) = *hwtstamps; __skb_complete_tx_timestamp(skb, sk, SCM_TSTAMP_SND, false); sock_put(sk); @@ -3997,7 +3997,7 @@ void skb_complete_wifi_ack(struct sk_buff *skb, bool acked) /* Take a reference to prevent skb_orphan() from freeing the socket, * but only if the socket refcount is not zero. */ - if (likely(atomic_inc_not_zero(&sk->sk_refcnt))) { + if (likely(refcount_inc_not_zero(&sk->sk_refcnt))) { err = sock_queue_err_skb(sk, skb); sock_put(sk); } diff --git a/net/core/sock.c b/net/core/sock.c index 0866d59489cb..ba0ef6a7dbaf 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -1708,7 +1708,7 @@ struct sock *sk_clone_lock(const struct sock *sk, const gfp_t priority) * (Documentation/RCU/rculist_nulls.txt for details) */ smp_wmb(); - atomic_set(&newsk->sk_refcnt, 2); + refcount_set(&newsk->sk_refcnt, 2); /* * Increment the counter in the same struct proto as the master @@ -1851,7 +1851,7 @@ void skb_orphan_partial(struct sk_buff *skb) ) { struct sock *sk = skb->sk; - if (atomic_inc_not_zero(&sk->sk_refcnt)) { + if (refcount_inc_not_zero(&sk->sk_refcnt)) { WARN_ON(refcount_sub_and_test(skb->truesize, &sk->sk_wmem_alloc)); skb->destructor = sock_efree; } @@ -2687,7 +2687,7 @@ void sock_init_data(struct socket *sock, struct sock *sk) * (Documentation/RCU/rculist_nulls.txt for details) */ smp_wmb(); - atomic_set(&sk->sk_refcnt, 1); + refcount_set(&sk->sk_refcnt, 1); atomic_set(&sk->sk_drops, 0); } EXPORT_SYMBOL(sock_init_data); -- cgit v1.2.3