From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Trond Myklebust Subject: [PATCH 4.9 039/172] NFSv4.1: Fix a race in nfs4_proc_layoutget Date: Mon, 3 Jul 2017 15:33:39 +0200 Message-Id: <20170703133416.076316084@linuxfoundation.org> In-Reply-To: <20170703133414.260777365@linuxfoundation.org> References: <20170703133414.260777365@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: 4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Trond Myklebust commit bd171930e6a3de4f5cffdafbb944e50093dfb59b upstream. If the task calling layoutget is signalled, then it is possible for the calls to nfs4_sequence_free_slot() and nfs4_layoutget_prepare() to race, in which case we leak a slot. The fix is to move the call to nfs4_sequence_free_slot() into the nfs4_layoutget_release() so that it gets called at task teardown time. Fixes: 2e80dbe7ac51 ("NFSv4.1: Close callback races for OPEN, LAYOUTGET...") Signed-off-by: Trond Myklebust Signed-off-by: Greg Kroah-Hartman --- fs/nfs/nfs4proc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/fs/nfs/nfs4proc.c +++ b/fs/nfs/nfs4proc.c @@ -8429,6 +8429,7 @@ static void nfs4_layoutget_release(void size_t max_pages = max_response_pages(server); dprintk("--> %s\n", __func__); + nfs4_sequence_free_slot(&lgp->res.seq_res); nfs4_free_pages(lgp->args.layout.pages, max_pages); pnfs_put_layout_hdr(NFS_I(inode)->layout); put_nfs_open_context(lgp->args.ctx); @@ -8503,7 +8504,6 @@ nfs4_proc_layoutget(struct nfs4_layoutge /* if layoutp->len is 0, nfs4_layoutget_prepare called rpc_exit */ if (status == 0 && lgp->res.layoutp->len) lseg = pnfs_layout_process(lgp); - nfs4_sequence_free_slot(&lgp->res.seq_res); rpc_put_task(task); dprintk("<-- %s status=%d\n", __func__, status); if (status)