From mboxrd@z Thu Jan 1 00:00:00 1970 From: Elena Reshetova Subject: [PATCH 01/36] net, llc: convert llc_sap.refcnt from atomic_t to refcount_t Date: Tue, 4 Jul 2017 15:52:56 +0300 Message-ID: <1499172811-16271-2-git-send-email-elena.reshetova@intel.com> References: <1499172811-16271-1-git-send-email-elena.reshetova@intel.com> Cc: peterz@infradead.org, jchapman@katalix.com, bfields@fieldses.org, linux-sctp@vger.kernel.org, jlayton@poochiereds.net, Elena Reshetova , steffen.klassert@secunet.com, zyan@redhat.com, herbert@gondor.apana.org.au, linux-x25@vger.kernel.org, linux-rdma@vger.kernel.org, bridge@lists.linux-foundation.org, jmorris@namei.org, 3chas3@gmail.com, kuznet@ms2.inr.ac.ru, jreuter@yaina.de, keescook@chromium.org, santosh.shilimkar@oracle.com, jhs@mojatatu.com, Hans Liljestrand , linux-hams@vger.kernel.org, David Windsor , linux-nfs@vger.kernel.org, sage@redhat.com, nhorman@tuxdriver.com, yoshfuji@linux-ipv6.org, vyasevich@gmail.com, linux-decnet-user@lists.sourceforge.net, linux-kernel@vger.kernel.org, ralf@linux-mips.org, kaber@trash.net, davem@davemloft.net To: netdev@vger.kernel.org Return-path: In-Reply-To: <1499172811-16271-1-git-send-email-elena.reshetova@intel.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: bridge-bounces@lists.linux-foundation.org Errors-To: bridge-bounces@lists.linux-foundation.org List-Id: netdev.vger.kernel.org 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 Signed-off-by: Hans Liljestrand Signed-off-by: Kees Cook Signed-off-by: David Windsor --- include/net/llc.h | 6 +++--- net/llc/llc_core.c | 2 +- 2 files changed, 4 insertions(+), 4 deletions(-) diff --git a/include/net/llc.h b/include/net/llc.h index e8e61d4..dc35f25 100644 --- a/include/net/llc.h +++ b/include/net/llc.h @@ -55,7 +55,7 @@ struct llc_sap { unsigned char state; unsigned char p_bit; unsigned char f_bit; - atomic_t refcnt; + refcount_t refcnt; int (*rcv_func)(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, @@ -113,14 +113,14 @@ struct llc_sap *llc_sap_open(unsigned char lsap, struct net_device *orig_dev)); static inline void llc_sap_hold(struct llc_sap *sap) { - atomic_inc(&sap->refcnt); + refcount_inc(&sap->refcnt); } void llc_sap_close(struct llc_sap *sap); static inline void llc_sap_put(struct llc_sap *sap) { - if (atomic_dec_and_test(&sap->refcnt)) + if (refcount_dec_and_test(&sap->refcnt)) llc_sap_close(sap); } diff --git a/net/llc/llc_core.c b/net/llc/llc_core.c index 842851c..8904126 100644 --- a/net/llc/llc_core.c +++ b/net/llc/llc_core.c @@ -41,7 +41,7 @@ static struct llc_sap *llc_sap_alloc(void) spin_lock_init(&sap->sk_lock); for (i = 0; i < LLC_SK_LADDR_HASH_ENTRIES; i++) INIT_HLIST_NULLS_HEAD(&sap->sk_laddr_hash[i], i); - atomic_set(&sap->refcnt, 1); + refcount_set(&sap->refcnt, 1); } return sap; } -- 2.7.4