From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga11.intel.com ([192.55.52.93]:34832 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750876AbdCNHHb (ORCPT ); Tue, 14 Mar 2017 03:07:31 -0400 From: Elena Reshetova To: trond.myklebust@primarydata.com Cc: linux-kernel@vger.kernel.org, linux-nfs@vger.kernel.org, anna.schumaker@netapp.com, peterz@infradead.org, keescook@chromium.org, Elena Reshetova , Hans Liljestrand , David Windsor Subject: [PATCH 02/12] fs, nfsd: convert nfs4_cntl_odstate.co_odcount from atomic_t to refcount_t Date: Tue, 14 Mar 2017 09:07:10 +0200 Message-Id: <1489475240-6594-3-git-send-email-elena.reshetova@intel.com> In-Reply-To: <1489475240-6594-1-git-send-email-elena.reshetova@intel.com> References: <1489475240-6594-1-git-send-email-elena.reshetova@intel.com> Sender: linux-nfs-owner@vger.kernel.org List-ID: 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 --- fs/nfsd/nfs4state.c | 6 +++--- fs/nfsd/state.h | 2 +- 2 files changed, 4 insertions(+), 4 deletions(-) diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c index ea1ce57..253fc93 100644 --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -568,7 +568,7 @@ alloc_clnt_odstate(struct nfs4_client *clp) co = kmem_cache_zalloc(odstate_slab, GFP_KERNEL); if (co) { co->co_client = clp; - atomic_set(&co->co_odcount, 1); + refcount_set(&co->co_odcount, 1); } return co; } @@ -586,7 +586,7 @@ static inline void get_clnt_odstate(struct nfs4_clnt_odstate *co) { if (co) - atomic_inc(&co->co_odcount); + refcount_inc(&co->co_odcount); } static void @@ -598,7 +598,7 @@ put_clnt_odstate(struct nfs4_clnt_odstate *co) return; fp = co->co_file; - if (atomic_dec_and_lock(&co->co_odcount, &fp->fi_lock)) { + if (refcount_dec_and_lock(&co->co_odcount, &fp->fi_lock)) { list_del(&co->co_perfile); spin_unlock(&fp->fi_lock); diff --git a/fs/nfsd/state.h b/fs/nfsd/state.h index f927aa4..58eb5f4 100644 --- a/fs/nfsd/state.h +++ b/fs/nfsd/state.h @@ -466,7 +466,7 @@ struct nfs4_clnt_odstate { struct nfs4_client *co_client; struct nfs4_file *co_file; struct list_head co_perfile; - atomic_t co_odcount; + refcount_t co_odcount; }; /* -- 2.7.4