Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752483AbdGDMyC (ORCPT ); Tue, 4 Jul 2017 08:54:02 -0400 Received: from mga06.intel.com ([134.134.136.31]:24205 "EHLO mga06.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752447AbdGDMx7 (ORCPT ); Tue, 4 Jul 2017 08:53:59 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.40,307,1496127600"; d="scan'208";a="1190387400" From: Elena Reshetova To: netdev@vger.kernel.org Cc: linux-kernel@vger.kernel.org, linux-decnet-user@lists.sourceforge.net, davem@davemloft.net, jmorris@namei.org, kaber@trash.net, yoshfuji@linux-ipv6.org, kuznet@ms2.inr.ac.ru, 3chas3@gmail.com, ralf@linux-mips.org, stephen@networkplumber.org, jchapman@katalix.com, jhs@mojatatu.com, bridge@lists.linux-foundation.org, linux-hams@vger.kernel.org, linux-x25@vger.kernel.org, peterz@infradead.org, keescook@chromium.org, linux-rdma@vger.kernel.org, linux-sctp@vger.kernel.org, vyasevich@gmail.com, nhorman@tuxdriver.com, linux-nfs@vger.kernel.org, zyan@redhat.com, sage@redhat.com, bfields@fieldses.org, jlayton@poochiereds.net, steffen.klassert@secunet.com, herbert@gondor.apana.org.au, santosh.shilimkar@oracle.com, jreuter@yaina.de, Elena Reshetova , Hans Liljestrand , David Windsor 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> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1499172811-16271-1-git-send-email-elena.reshetova@intel.com> References: <1499172811-16271-1-git-send-email-elena.reshetova@intel.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1813 Lines: 60 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