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, Oleg Drokin , Trond Myklebust , Jason L Tibbitts III Subject: [PATCH 4.7 143/143] SUNRPC: Fix infinite looping in rpc_clnt_iterate_for_each_xprt Date: Mon, 5 Sep 2016 18:45:19 +0200 Message-Id: <20160905164436.655274523@linuxfoundation.org> In-Reply-To: <20160905164430.593075551@linuxfoundation.org> References: <20160905164430.593075551@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: 4.7-stable review patch. If anyone has any objections, please let me know. ------------------ From: Trond Myklebust commit bdc54d8e3cb4a41dddcabfd86d9eb3aa5f622b75 upstream. If there were less than 2 entries in the multipath list, then xprt_iter_next_entry_multiple() would never advance beyond the first entry, which is correct for round robin behaviour, but not for the list iteration. The end result would be infinite looping in rpc_clnt_iterate_for_each_xprt() as we would never see the xprt == NULL condition fulfilled. Reported-by: Oleg Drokin Fixes: 80b14d5e61ca ("SUNRPC: Add a structure to track multiple transports") Signed-off-by: Trond Myklebust Cc: Jason L Tibbitts III Signed-off-by: Greg Kroah-Hartman --- net/sunrpc/xprtmultipath.c | 8 +++----- 1 file changed, 3 insertions(+), 5 deletions(-) --- a/net/sunrpc/xprtmultipath.c +++ b/net/sunrpc/xprtmultipath.c @@ -271,14 +271,12 @@ struct rpc_xprt *xprt_iter_next_entry_mu xprt_switch_find_xprt_t find_next) { struct rpc_xprt_switch *xps = rcu_dereference(xpi->xpi_xpswitch); - struct list_head *head; if (xps == NULL) return NULL; - head = &xps->xps_xprt_list; - if (xps->xps_nxprts < 2) - return xprt_switch_find_first_entry(head); - return xprt_switch_set_next_cursor(head, &xpi->xpi_cursor, find_next); + return xprt_switch_set_next_cursor(&xps->xps_xprt_list, + &xpi->xpi_cursor, + find_next); } static