commit e45d1a1835b889676374fb74ff4d0e6b06ad173f
author Trond Myklebust <trondmy@gmail.com> Tue Apr 09 12:13:42 2019 -0400
committer J. Bruce Fields <bfields@redhat.com> Wed Apr 24 09:46:35 2019 -0400
tree ccb99869e92ef128774ab5a9f2405d3e869a4a80
parent e6667c73a27d80078f8d7fca516d6b14bc4e18a7

nfsd: knfsd must use the container user namespace

Convert knfsd to use the user namespace of the container that started
the server processes.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

fs/nfsd/nfs3xdr.c

diff --git a/fs/nfsd/nfs3xdr.c b/fs/nfsd/nfs3xdr.c
index 8d78912..fcf3182 100644
--- a/fs/nfsd/nfs3xdr.c
+++ b/fs/nfsd/nfs3xdr.c
@@ -96,7 +96,7 @@
 }
 
 static __be32 *
-decode_sattr3(__be32 *p, struct iattr *iap)
+decode_sattr3(__be32 *p, struct iattr *iap, struct user_namespace *userns)
 {
 	u32	tmp;
 
@@ -107,12 +107,12 @@
 		iap->ia_mode = ntohl(*p++);
 	}
 	if (*p++) {
-		iap->ia_uid = make_kuid(&init_user_ns, ntohl(*p++));
+		iap->ia_uid = make_kuid(userns, ntohl(*p++));
 		if (uid_valid(iap->ia_uid))
 			iap->ia_valid |= ATTR_UID;
 	}
 	if (*p++) {
-		iap->ia_gid = make_kgid(&init_user_ns, ntohl(*p++));
+		iap->ia_gid = make_kgid(userns, ntohl(*p++));
 		if (gid_valid(iap->ia_gid))
 			iap->ia_valid |= ATTR_GID;
 	}
@@ -165,12 +165,13 @@
 encode_fattr3(struct svc_rqst *rqstp, __be32 *p, struct svc_fh *fhp,
 	      struct kstat *stat)
 {
+	struct user_namespace *userns = nfsd_user_namespace(rqstp);
 	struct timespec ts;
 	*p++ = htonl(nfs3_ftypes[(stat->mode & S_IFMT) >> 12]);
 	*p++ = htonl((u32) (stat->mode & S_IALLUGO));
 	*p++ = htonl((u32) stat->nlink);
-	*p++ = htonl((u32) from_kuid(&init_user_ns, stat->uid));
-	*p++ = htonl((u32) from_kgid(&init_user_ns, stat->gid));
+	*p++ = htonl((u32) from_kuid_munged(userns, stat->uid));
+	*p++ = htonl((u32) from_kgid_munged(userns, stat->gid));
 	if (S_ISLNK(stat->mode) && stat->size > NFS3_MAXPATHLEN) {
 		p = xdr_encode_hyper(p, (u64) NFS3_MAXPATHLEN);
 	} else {
@@ -325,7 +326,7 @@
 	p = decode_fh(p, &args->fh);
 	if (!p)
 		return 0;
-	p = decode_sattr3(p, &args->attrs);
+	p = decode_sattr3(p, &args->attrs, nfsd_user_namespace(rqstp));
 
 	if ((args->check_guard = ntohl(*p++)) != 0) { 
 		struct timespec time; 
@@ -455,7 +456,7 @@
 	switch (args->createmode = ntohl(*p++)) {
 	case NFS3_CREATE_UNCHECKED:
 	case NFS3_CREATE_GUARDED:
-		p = decode_sattr3(p, &args->attrs);
+		p = decode_sattr3(p, &args->attrs, nfsd_user_namespace(rqstp));
 		break;
 	case NFS3_CREATE_EXCLUSIVE:
 		args->verf = p;
@@ -476,7 +477,7 @@
 	if (!(p = decode_fh(p, &args->fh)) ||
 	    !(p = decode_filename(p, &args->name, &args->len)))
 		return 0;
-	p = decode_sattr3(p, &args->attrs);
+	p = decode_sattr3(p, &args->attrs, nfsd_user_namespace(rqstp));
 
 	return xdr_argsize_check(rqstp, p);
 }
@@ -491,7 +492,7 @@
 	if (!(p = decode_fh(p, &args->ffh)) ||
 	    !(p = decode_filename(p, &args->fname, &args->flen)))
 		return 0;
-	p = decode_sattr3(p, &args->attrs);
+	p = decode_sattr3(p, &args->attrs, nfsd_user_namespace(rqstp));
 
 	args->tlen = ntohl(*p++);
 
@@ -519,7 +520,7 @@
 
 	if (args->ftype == NF3BLK  || args->ftype == NF3CHR
 	 || args->ftype == NF3SOCK || args->ftype == NF3FIFO)
-		p = decode_sattr3(p, &args->attrs);
+		p = decode_sattr3(p, &args->attrs, nfsd_user_namespace(rqstp));
 
 	if (args->ftype == NF3BLK || args->ftype == NF3CHR) {
 		args->major = ntohl(*p++);