Commit cc45f017 authored by Al Viro's avatar Al Viro Committed by Linus Torvalds
Browse files

[PATCH] bug: nfsd/nfs4xdr.c misuse of ERR_PTR() 



	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: default avatarAl Viro <viro@zeniv.linux.org.uk>
Acked-by: default avatarTrond Myklebust <trond.myklebust@fys.uio.no>
Acked-by: default avatarNeil Brown <neilb@suse.de>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent b7766da7

fs/nfsd/nfs4xdr.c

+11 −10
Original line number Diff line number Diff line
@@ -1292,16 +1292,15 @@ static int nfsd4_encode_fs_location4(struct nfsd4_fs_location *location, 
 * 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 *rqstp, struct svc_export *exp) 
	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(struct svc_rqst *rqstp, 
				     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;

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