NFSv4.2: Fix initialisation of struct nfs4_label

[ Upstream commit c528f70 ]

The call to nfs4_label_init_security() should return a fully initialised
label.

Fixes: aa9c266 ("NFS: Client implementation of Labeled-NFS")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

fs/nfs/nfs4proc.c

@@ -126,6 +126,11 @@ nfs4_label_init_security(struct inode *dir, struct dentry *dentry,
 	if (nfs_server_capable(dir, NFS_CAP_SECURITY_LABEL) == 0)
 		return NULL;
 
+	label->lfs = 0;
+	label->pi = 0;
+	label->len = 0;
+	label->label = NULL;
+
 	err = security_dentry_init_security(dentry, sattr->ia_mode,
 				&dentry->d_name, (void **)&label->label, &label->len);
 	if (err == 0)
@@ -3823,7 +3828,7 @@ nfs4_atomic_open(struct inode *dir, struct nfs_open_context *ctx,
 		int open_flags, struct iattr *attr, int *opened)
 {
 	struct nfs4_state *state;
-	struct nfs4_label l = {0, 0, 0, NULL}, *label = NULL;
+	struct nfs4_label l, *label;
 
 	label = nfs4_label_init_security(dir, ctx->dentry, attr, &l);
 
@@ -4657,7 +4662,7 @@ nfs4_proc_create(struct inode *dir, struct dentry *dentry, struct iattr *sattr,
 		 int flags)
 {
 	struct nfs_server *server = NFS_SERVER(dir);
-	struct nfs4_label l, *ilabel = NULL;
+	struct nfs4_label l, *ilabel;
 	struct nfs_open_context *ctx;
 	struct nfs4_state *state;
 	int status = 0;
@@ -5017,7 +5022,7 @@ static int nfs4_proc_symlink(struct inode *dir, struct dentry *dentry,
 	struct nfs4_exception exception = {
 		.interruptible = true,
 	};
-	struct nfs4_label l, *label = NULL;
+	struct nfs4_label l, *label;
 	int err;
 
 	label = nfs4_label_init_security(dir, dentry, sattr, &l);
@@ -5058,7 +5063,7 @@ static int nfs4_proc_mkdir(struct inode *dir, struct dentry *dentry,
 	struct nfs4_exception exception = {
 		.interruptible = true,
 	};
-	struct nfs4_label l, *label = NULL;
+	struct nfs4_label l, *label;
 	int err;
 
 	label = nfs4_label_init_security(dir, dentry, sattr, &l);
@@ -5177,7 +5182,7 @@ static int nfs4_proc_mknod(struct inode *dir, struct dentry *dentry,
 	struct nfs4_exception exception = {
 		.interruptible = true,
 	};
-	struct nfs4_label l, *label = NULL;
+	struct nfs4_label l, *label;
 	int err;
 
 	label = nfs4_label_init_security(dir, dentry, sattr, &l);