From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751997AbWJJDKm (ORCPT ); Mon, 9 Oct 2006 23:10:42 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751999AbWJJDKm (ORCPT ); Mon, 9 Oct 2006 23:10:42 -0400 Received: from zeniv.linux.org.uk ([195.92.253.2]:43680 "EHLO ZenIV.linux.org.uk") by vger.kernel.org with ESMTP id S1751997AbWJJDKl (ORCPT ); Mon, 9 Oct 2006 23:10:41 -0400 To: linux-kernel@vger.kernel.org Subject: [PATCH 1/25] bug: nfsd/nfs4xdr.c misuse of ERR_PTR() Cc: neilb@cse.unsw.edu.au, trond.myklebust@fys.uio.no Message-Id: From: Al Viro Date: Tue, 10 Oct 2006 04:10:40 +0100 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org a) ERR_PTR(nfserr_something) is a bad idea; IS_ERR() will be false for it. b) mixing nfserr_.... with -EOPNOTSUPP is even worse idea. nfsd4_path() does both; caller expects to get NFS protocol error out it if anything goes wrong, but if it does we either do not notice (see (a)) or get host-endian negative (see (b)). IOW, that's a case when we can't use ERR_PTR() to return error, even though we return a pointer in case of success. Signed-off-by: Al Viro --- fs/nfsd/nfs4xdr.c | 21 +++++++++++---------- 1 files changed, 11 insertions(+), 10 deletions(-) diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c index 41fc241..77be0c4 100644 --- a/fs/nfsd/nfs4xdr.c +++ b/fs/nfsd/nfs4xdr.c @@ -1292,16 +1292,15 @@ static int nfsd4_encode_fs_location4(str * Returned string is safe to use as long as the caller holds a reference * to @exp. */ -static char *nfsd4_path(struct svc_rqst *rqstp, struct svc_export *exp) +static char *nfsd4_path(struct svc_rqst *rqstp, struct svc_export *exp, u32 *stat) { struct svc_fh tmp_fh; char *path, *rootpath; - int stat; fh_init(&tmp_fh, NFS4_FHSIZE); - stat = exp_pseudoroot(rqstp->rq_client, &tmp_fh, &rqstp->rq_chandle); - if (stat) - return ERR_PTR(stat); + *stat = exp_pseudoroot(rqstp->rq_client, &tmp_fh, &rqstp->rq_chandle); + if (*stat) + return NULL; rootpath = tmp_fh.fh_export->ex_path; path = exp->ex_path; @@ -1309,7 +1308,8 @@ static char *nfsd4_path(struct svc_rqst if (strncmp(path, rootpath, strlen(rootpath))) { printk("nfsd: fs_locations failed;" "%s is not contained in %s\n", path, rootpath); - return ERR_PTR(-EOPNOTSUPP); + *stat = nfserr_notsupp; + return NULL; } return path + strlen(rootpath); @@ -1322,13 +1322,14 @@ static int nfsd4_encode_fs_locations(str struct svc_export *exp, u32 **pp, int *buflen) { - int status, i; + u32 status; + int i; u32 *p = *pp; struct nfsd4_fs_locations *fslocs = &exp->ex_fslocs; - char *root = nfsd4_path(rqstp, exp); + char *root = nfsd4_path(rqstp, exp, &status); - if (IS_ERR(root)) - return PTR_ERR(root); + if (status) + return status; status = nfsd4_encode_components('/', root, &p, buflen); if (status) return status; -- 1.4.2.GIT