From mboxrd@z Thu Jan 1 00:00:00 1970 From: Elena Reshetova Subject: [PATCH 01/18] net, llc: convert llc_sap.refcnt from atomic_t to refcount_t Date: Fri, 17 Mar 2017 13:12:42 +0200 Message-ID: <1489749179-12063-2-git-send-email-elena.reshetova@intel.com> References: <1489749179-12063-1-git-send-email-elena.reshetova@intel.com> Return-path: DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=intel.com; i=@intel.com; q=dns/txt; s=intel; t=1489749203; x=1521285203; h=from:to:cc:subject:date:message-id:in-reply-to: references; bh=j+VqZv1UcvzyxiywqCtqAvyZXwl/AYEctv/8y6RT9aM=; b=Io8dtiMFRXsQNe3pzTozH+4wTB7BBPBd0rMIk0oecUQ/ktiNuPnKcr7+ l+HeY3VcQqHIZbfaViwY2fVNTb4Dfw==; In-Reply-To: <1489749179-12063-1-git-send-email-elena.reshetova@intel.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit 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, linux-bluetooth@vger.kernel.org, marcel@holtmann.org, johan.hedberg@gmail.com, peterz@infradead.org, keescook@chromium.org, Elena Reshetova , Hans Liljestrand , David Windsor 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