Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753158AbdGDM7K (ORCPT ); Tue, 4 Jul 2017 08:59:10 -0400 Received: from mga09.intel.com ([134.134.136.24]:35996 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752254AbdGDM7G (ORCPT ); Tue, 4 Jul 2017 08:59:06 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.40,307,1496127600"; d="scan'208";a="1190388682" 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 36/36] net, ax25: convert ax25_cb.refcount from atomic_t to refcount_t Date: Tue, 4 Jul 2017 15:53:31 +0300 Message-Id: <1499172811-16271-37-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: 1777 Lines: 57 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/ax25.h | 6 +++--- net/ax25/af_ax25.c | 2 +- 2 files changed, 4 insertions(+), 4 deletions(-) diff --git a/include/net/ax25.h b/include/net/ax25.h index e3467ba..c4a0cf6 100644 --- a/include/net/ax25.h +++ b/include/net/ax25.h @@ -244,7 +244,7 @@ typedef struct ax25_cb { unsigned char window; struct timer_list timer, dtimer; struct sock *sk; /* Backlink to socket */ - atomic_t refcount; + refcount_t refcount; } ax25_cb; struct ax25_sock { @@ -266,11 +266,11 @@ static inline struct ax25_cb *sk_to_ax25(const struct sock *sk) hlist_for_each_entry(__ax25, list, ax25_node) #define ax25_cb_hold(__ax25) \ - atomic_inc(&((__ax25)->refcount)) + refcount_inc(&((__ax25)->refcount)) static __inline__ void ax25_cb_put(ax25_cb *ax25) { - if (atomic_dec_and_test(&ax25->refcount)) { + if (refcount_dec_and_test(&ax25->refcount)) { kfree(ax25->digipeat); kfree(ax25); } diff --git a/net/ax25/af_ax25.c b/net/ax25/af_ax25.c index 0c92ba0..f3f9d18 100644 --- a/net/ax25/af_ax25.c +++ b/net/ax25/af_ax25.c @@ -510,7 +510,7 @@ ax25_cb *ax25_create_cb(void) if ((ax25 = kzalloc(sizeof(*ax25), GFP_ATOMIC)) == NULL) return NULL; - atomic_set(&ax25->refcount, 1); + refcount_set(&ax25->refcount, 1); skb_queue_head_init(&ax25->write_queue); skb_queue_head_init(&ax25->frag_queue); -- 2.7.4