nfsd/idmap: return nfserr_inval for 0-length names

Tigran Mkrtchyan's new pynfs testcases for zero length principals fail:

SATT16   st_setattr.testEmptyPrincipal                            : FAILURE
           Setting empty owner should return NFS4ERR_INVAL,
           instead got NFS4ERR_BADOWNER
SATT17   st_setattr.testEmptyGroupPrincipal                       : FAILURE
           Setting empty owner_group should return NFS4ERR_INVAL,
           instead got NFS4ERR_BADOWNER

This patch checks the principal and returns nfserr_inval directly.  It
could check after decoding in nfs4xdr.c, but it's simpler to do it in
nfsd_map_xxxx.

Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

1 files changed, 8 insertions, 0 deletions

diff --git a/fs/nfsd/nfs4idmap.c b/fs/nfsd/nfs4idmap.c
index 5b20577dcdd2..6b9b6cca469f 100644
--- a/fs/nfsd/nfs4idmap.c
+++ b/fs/nfsd/nfs4idmap.c
@@ -628,6 +628,10 @@ nfsd_map_name_to_uid(struct svc_rqst *rqstp, const char *name, size_t namelen,
 {
         __be32 status;
         u32 id = -1;
+
+        if (name == NULL || namelen == 0)
+                return nfserr_inval;
+
         status = do_name_to_id(rqstp, IDMAP_TYPE_USER, name, namelen, &id);
         *uid = make_kuid(&init_user_ns, id);
         if (!uid_valid(*uid))
@@ -641,6 +645,10 @@ nfsd_map_name_to_gid(struct svc_rqst *rqstp, const char *name, size_t namelen,
 {
         __be32 status;
         u32 id = -1;
+
+        if (name == NULL || namelen == 0)
+                return nfserr_inval;
+
         status = do_name_to_id(rqstp, IDMAP_TYPE_GROUP, name, namelen, &id);
         *gid = make_kgid(&init_user_ns, id);
         if (!gid_valid(*gid))