Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751405AbdCQMLa (ORCPT ); Fri, 17 Mar 2017 08:11:30 -0400 Received: from mga02.intel.com ([134.134.136.20]:50956 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751035AbdCQMLZ (ORCPT ); Fri, 17 Mar 2017 08:11:25 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.36,176,1486454400"; d="scan'208";a="78173653" From: Elena Reshetova To: netdev@vger.kernel.org Cc: linux-kernel@vger.kernel.org, linux-rdma@vger.kernel.org, davem@davemloft.net, linux-x25@vger.kernel.org, linux-sctp@vger.kernel.org, vyasevich@gmail.com, nhorman@tuxdriver.com, linux-hams@vger.kernel.org, linux-nfs@vger.kernel.org, ceph-devel@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, ralf@linux-mips.org, peterz@infradead.org, keescook@chromium.org, Elena Reshetova , Hans Liljestrand , David Windsor Subject: [PATCH 04/23] net, ceph: convert ceph_snap_context.nref from atomic_t to refcount_t Date: Fri, 17 Mar 2017 14:10:27 +0200 Message-Id: <1489752646-8749-5-git-send-email-elena.reshetova@intel.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1489752646-8749-1-git-send-email-elena.reshetova@intel.com> References: <1489752646-8749-1-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: 1992 Lines: 69 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/linux/ceph/libceph.h | 3 ++- net/ceph/snapshot.c | 6 +++--- 2 files changed, 5 insertions(+), 4 deletions(-) diff --git a/include/linux/ceph/libceph.h b/include/linux/ceph/libceph.h index 1816c5e..26dc674 100644 --- a/include/linux/ceph/libceph.h +++ b/include/linux/ceph/libceph.h @@ -14,6 +14,7 @@ #include #include #include +#include #include #include @@ -159,7 +160,7 @@ struct ceph_client { * dirtied. */ struct ceph_snap_context { - atomic_t nref; + refcount_t nref; u64 seq; u32 num_snaps; u64 snaps[]; diff --git a/net/ceph/snapshot.c b/net/ceph/snapshot.c index 705414e..e14a5d0 100644 --- a/net/ceph/snapshot.c +++ b/net/ceph/snapshot.c @@ -49,7 +49,7 @@ struct ceph_snap_context *ceph_create_snap_context(u32 snap_count, if (!snapc) return NULL; - atomic_set(&snapc->nref, 1); + refcount_set(&snapc->nref, 1); snapc->num_snaps = snap_count; return snapc; @@ -59,7 +59,7 @@ EXPORT_SYMBOL(ceph_create_snap_context); struct ceph_snap_context *ceph_get_snap_context(struct ceph_snap_context *sc) { if (sc) - atomic_inc(&sc->nref); + refcount_inc(&sc->nref); return sc; } EXPORT_SYMBOL(ceph_get_snap_context); @@ -68,7 +68,7 @@ void ceph_put_snap_context(struct ceph_snap_context *sc) { if (!sc) return; - if (atomic_dec_and_test(&sc->nref)) { + if (refcount_dec_and_test(&sc->nref)) { /*printk(" deleting snap_context %p\n", sc);*/ kfree(sc); } -- 2.7.4