Return-Path: Received: from fieldses.org ([173.255.197.46]:36284 "EHLO fieldses.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751510AbcECTQG (ORCPT ); Tue, 3 May 2016 15:16:06 -0400 Date: Tue, 3 May 2016 15:16:02 -0400 To: Trond Myklebust , Anna Schumaker Cc: linux-nfs@vger.kernel.org, "Eric W. Biederman" Subject: [PATCH] nfs: don't share mounts between network namespaces Message-ID: <20160503191602.GA17518@fieldses.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii From: bfields@fieldses.org (J. Bruce Fields) Sender: linux-nfs-owner@vger.kernel.org List-ID: From: "J. Bruce Fields" There's no guarantee that an IP address in a different network namespace actually represents the same endpoint. Also, if we allow unprivileged nfs mounts some day then this might allow an unprivileged user in another network namespace to misdirect somebody else's nfs mounts. If sharing between containers is really what's wanted then that could still be arranged explicitly, for example with bind mounts. Reported-by: "Eric W. Biederman" Signed-off-by: J. Bruce Fields --- fs/nfs/super.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/fs/nfs/super.c b/fs/nfs/super.c index f1268280244e..ff537a205188 100644 --- a/fs/nfs/super.c +++ b/fs/nfs/super.c @@ -2408,6 +2408,11 @@ static int nfs_compare_super_address(struct nfs_server *server1, struct nfs_server *server2) { struct sockaddr *sap1, *sap2; + struct rpc_xprt *xprt1 = server1->client->cl_xprt; + struct rpc_xprt *xprt2 = server2->client->cl_xprt; + + if (!net_eq(xprt1->xprt_net, xprt2->xprt_net)) + return 0; sap1 = (struct sockaddr *)&server1->nfs_client->cl_addr; sap2 = (struct sockaddr *)&server2->nfs_client->cl_addr; -- 2.5.5