From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga11.intel.com ([192.55.52.93]:63979 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750849AbdCNHHv (ORCPT ); Tue, 14 Mar 2017 03:07:51 -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 09/12] fs, nfs: convert nfs4_lock_state.ls_count from atomic_t to refcount_t Date: Tue, 14 Mar 2017 09:07:17 +0200 Message-Id: <1489475240-6594-10-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/nfs/nfs4_fs.h | 2 +- fs/nfs/nfs4proc.c | 6 +++--- fs/nfs/nfs4state.c | 8 ++++---- 3 files changed, 8 insertions(+), 8 deletions(-) diff --git a/fs/nfs/nfs4_fs.h b/fs/nfs/nfs4_fs.h index 6651658..e62ed94 100644 --- a/fs/nfs/nfs4_fs.h +++ b/fs/nfs/nfs4_fs.h @@ -144,7 +144,7 @@ struct nfs4_lock_state { unsigned long ls_flags; struct nfs_seqid_counter ls_seqid; nfs4_stateid ls_stateid; - atomic_t ls_count; + refcount_t ls_count; fl_owner_t ls_owner; }; diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c index 0a0eaec..2c85c9f 100644 --- a/fs/nfs/nfs4proc.c +++ b/fs/nfs/nfs4proc.c @@ -2597,7 +2597,7 @@ static int nfs41_check_expired_locks(struct nfs4_state *state) if (test_bit(NFS_LOCK_INITIALIZED, &lsp->ls_flags)) { struct rpc_cred *cred = lsp->ls_state->owner->so_cred; - atomic_inc(&lsp->ls_count); + refcount_inc(&lsp->ls_count); spin_unlock(&state->state_lock); nfs4_put_lock_state(prev); @@ -5927,7 +5927,7 @@ static struct nfs4_unlockdata *nfs4_alloc_unlockdata(struct file_lock *fl, p->arg.seqid = seqid; p->res.seqid = seqid; p->lsp = lsp; - atomic_inc(&lsp->ls_count); + refcount_inc(&lsp->ls_count); /* Ensure we don't close file until we're done freeing locks! */ p->ctx = get_nfs_open_context(ctx); memcpy(&p->fl, fl, sizeof(p->fl)); @@ -6135,7 +6135,7 @@ static struct nfs4_lockdata *nfs4_alloc_lockdata(struct file_lock *fl, p->res.lock_seqid = p->arg.lock_seqid; p->lsp = lsp; p->server = server; - atomic_inc(&lsp->ls_count); + refcount_inc(&lsp->ls_count); p->ctx = get_nfs_open_context(ctx); memcpy(&p->fl, fl, sizeof(p->fl)); return p; diff --git a/fs/nfs/nfs4state.c b/fs/nfs/nfs4state.c index daeb94e..347cb18 100644 --- a/fs/nfs/nfs4state.c +++ b/fs/nfs/nfs4state.c @@ -819,7 +819,7 @@ __nfs4_find_lock_state(struct nfs4_state *state, ret = pos; } if (ret) - atomic_inc(&ret->ls_count); + refcount_inc(&ret->ls_count); return ret; } @@ -837,7 +837,7 @@ static struct nfs4_lock_state *nfs4_alloc_lock_state(struct nfs4_state *state, f if (lsp == NULL) return NULL; nfs4_init_seqid_counter(&lsp->ls_seqid); - atomic_set(&lsp->ls_count, 1); + refcount_set(&lsp->ls_count, 1); lsp->ls_state = state; lsp->ls_owner = fl_owner; lsp->ls_seqid.owner_id = ida_simple_get(&server->lockowner_id, 0, 0, GFP_NOFS); @@ -901,7 +901,7 @@ void nfs4_put_lock_state(struct nfs4_lock_state *lsp) if (lsp == NULL) return; state = lsp->ls_state; - if (!atomic_dec_and_lock(&lsp->ls_count, &state->state_lock)) + if (!refcount_dec_and_lock(&lsp->ls_count, &state->state_lock)) return; list_del(&lsp->ls_locks); if (list_empty(&state->lock_states)) @@ -921,7 +921,7 @@ static void nfs4_fl_copy_lock(struct file_lock *dst, struct file_lock *src) struct nfs4_lock_state *lsp = src->fl_u.nfs4_fl.owner; dst->fl_u.nfs4_fl.owner = lsp; - atomic_inc(&lsp->ls_count); + refcount_inc(&lsp->ls_count); } static void nfs4_fl_release_lock(struct file_lock *fl) -- 2.7.4