Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752688AbdGDM5O (ORCPT ); Tue, 4 Jul 2017 08:57:14 -0400 Received: from mga04.intel.com ([192.55.52.120]:58463 "EHLO mga04.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752338AbdGDM5K (ORCPT ); Tue, 4 Jul 2017 08:57:10 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.40,307,1496127600"; d="scan'208";a="1190388240" 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 23/36] net, rds: convert rds_message.m_refcount from atomic_t to refcount_t Date: Tue, 4 Jul 2017 15:53:18 +0300 Message-Id: <1499172811-16271-24-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: 2439 Lines: 67 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 --- net/rds/message.c | 12 ++++++------ net/rds/rds.h | 2 +- 2 files changed, 7 insertions(+), 7 deletions(-) diff --git a/net/rds/message.c b/net/rds/message.c index 49bfb51..4318cc9 100644 --- a/net/rds/message.c +++ b/net/rds/message.c @@ -48,8 +48,8 @@ static unsigned int rds_exthdr_size[__RDS_EXTHDR_MAX] = { void rds_message_addref(struct rds_message *rm) { - rdsdebug("addref rm %p ref %d\n", rm, atomic_read(&rm->m_refcount)); - atomic_inc(&rm->m_refcount); + rdsdebug("addref rm %p ref %d\n", rm, refcount_read(&rm->m_refcount)); + refcount_inc(&rm->m_refcount); } EXPORT_SYMBOL_GPL(rds_message_addref); @@ -83,9 +83,9 @@ static void rds_message_purge(struct rds_message *rm) void rds_message_put(struct rds_message *rm) { - rdsdebug("put rm %p ref %d\n", rm, atomic_read(&rm->m_refcount)); - WARN(!atomic_read(&rm->m_refcount), "danger refcount zero on %p\n", rm); - if (atomic_dec_and_test(&rm->m_refcount)) { + rdsdebug("put rm %p ref %d\n", rm, refcount_read(&rm->m_refcount)); + WARN(!refcount_read(&rm->m_refcount), "danger refcount zero on %p\n", rm); + if (refcount_dec_and_test(&rm->m_refcount)) { BUG_ON(!list_empty(&rm->m_sock_item)); BUG_ON(!list_empty(&rm->m_conn_item)); rds_message_purge(rm); @@ -206,7 +206,7 @@ struct rds_message *rds_message_alloc(unsigned int extra_len, gfp_t gfp) rm->m_used_sgs = 0; rm->m_total_sgs = extra_len / sizeof(struct scatterlist); - atomic_set(&rm->m_refcount, 1); + refcount_set(&rm->m_refcount, 1); INIT_LIST_HEAD(&rm->m_sock_item); INIT_LIST_HEAD(&rm->m_conn_item); spin_lock_init(&rm->m_rs_lock); diff --git a/net/rds/rds.h b/net/rds/rds.h index ea72d6e..516bcc8 100644 --- a/net/rds/rds.h +++ b/net/rds/rds.h @@ -356,7 +356,7 @@ static inline u32 rds_rdma_cookie_offset(rds_rdma_cookie_t cookie) #define RDS_MSG_FLUSH 8 struct rds_message { - atomic_t m_refcount; + refcount_t m_refcount; struct list_head m_sock_item; struct list_head m_conn_item; struct rds_incoming m_inc; -- 2.7.4