3 files changed, 32 insertions, 8 deletions

diff --git a/include/linux/shmem_fs.h b/include/linux/shmem_fs.h
index 30aa0dc60d75..9d55438bc4ad 100644
--- a/include/linux/shmem_fs.h
+++ b/include/linux/shmem_fs.h
@@ -47,6 +47,8 @@ extern int shmem_init(void);
 extern int shmem_fill_super(struct super_block *sb, void *data, int silent);
 extern struct file *shmem_file_setup(const char *name,
                                         loff_t size, unsigned long flags);
+extern struct file *shmem_kernel_file_setup(const char *name, loff_t size,
+                                            unsigned long flags);
 extern int shmem_zero_setup(struct vm_area_struct *);
 extern int shmem_lock(struct file *file, int lock, struct user_struct *user);
 extern void shmem_unlock_mapping(struct address_space *mapping);
diff --git a/mm/shmem.c b/mm/shmem.c
index 8297623fcaed..902a14842b74 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -2918,13 +2918,8 @@ static struct dentry_operations anon_ops = {
         .d_dname = simple_dname
 };
 
-/**
- * shmem_file_setup - get an unlinked file living in tmpfs
- * @name: name for dentry (to be seen in /proc/<pid>/maps
- * @size: size to be set for the file
- * @flags: VM_NORESERVE suppresses pre-accounting of the entire object size
- */
-struct file *shmem_file_setup(const char *name, loff_t size, unsigned long flags)
+static struct file *__shmem_file_setup(const char *name, loff_t size,
+                                       unsigned long flags, unsigned int i_flags)
 {
         struct file *res;
         struct inode *inode;
@@ -2957,6 +2952,7 @@ struct file *shmem_file_setup(const char *name, loff_t size, unsigned long flags
         if (!inode)
                 goto put_dentry;
 
+        inode->i_flags |= i_flags;
         d_instantiate(path.dentry, inode);
         inode->i_size = size;
         clear_nlink(inode);     /* It is unlinked */
@@ -2977,6 +2973,32 @@ put_memory:
         shmem_unacct_size(flags, size);
         return res;
 }
+
+/**
+ * shmem_kernel_file_setup - get an unlinked file living in tmpfs which must be
+ *      kernel internal.  There will be NO LSM permission checks against the
+ *      underlying inode.  So users of this interface must do LSM checks at a
+ *      higher layer.  The one user is the big_key implementation.  LSM checks
+ *      are provided at the key level rather than the inode level.
+ * @name: name for dentry (to be seen in /proc/<pid>/maps
+ * @size: size to be set for the file
+ * @flags: VM_NORESERVE suppresses pre-accounting of the entire object size
+ */
+struct file *shmem_kernel_file_setup(const char *name, loff_t size, unsigned long flags)
+{
+        return __shmem_file_setup(name, size, flags, S_PRIVATE);
+}
+
+/**
+ * shmem_file_setup - get an unlinked file living in tmpfs
+ * @name: name for dentry (to be seen in /proc/<pid>/maps
+ * @size: size to be set for the file
+ * @flags: VM_NORESERVE suppresses pre-accounting of the entire object size
+ */
+struct file *shmem_file_setup(const char *name, loff_t size, unsigned long flags)
+{
+        return __shmem_file_setup(name, size, flags, 0);
+}
 EXPORT_SYMBOL_GPL(shmem_file_setup);
 
 /**
diff --git a/security/keys/big_key.c b/security/keys/big_key.c
index 7f44c3207a9b..8137b27d641d 100644
--- a/security/keys/big_key.c
+++ b/security/keys/big_key.c
@@ -70,7 +70,7 @@ int big_key_instantiate(struct key *key, struct key_preparsed_payload *prep)
                  *
                  * TODO: Encrypt the stored data with a temporary key.
                  */
-                file = shmem_file_setup("", datalen, 0);
+                file = shmem_kernel_file_setup("", datalen, 0);
                 if (IS_ERR(file)) {
                         ret = PTR_ERR(file);
                         goto err_quota;