ramfs: Initialize security of in-memory inodes

Add a call security_inode_init_security() after ramfs_get_inode(), to let
LSMs initialize the inode security field. Skip ramfs_fill_super(), as the
initialization is done through the sb_set_mnt_opts hook.

Calling security_inode_init_security() call inside ramfs_get_inode() is
not possible since, for CONFIG_SHMEM=n, tmpfs also calls the former after
the latter.

Pass NULL as initxattrs() callback to security_inode_init_security(), since
the purpose of the call is only to initialize the in-memory inodes.

Cc: Hugh Dickins <hughd@google.com>
Acked-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

diff --git a/fs/ramfs/inode.c b/fs/ramfs/inode.c
index 4ac05a9e25bc2334b8a7fed348c524ea984beb13..8006faaaf0ec7d99fb7e49b2e677a07325c68a43 100644 (file)
--- a/fs/ramfs/inode.c
+++ b/fs/ramfs/inode.c
@@ -102,11 +102,20 @@ ramfs_mknod(struct mnt_idmap *idmap, struct inode *dir,
        int error = -ENOSPC;
 
        if (inode) {
+               error = security_inode_init_security(inode, dir,
+                                                    &dentry->d_name, NULL,
+                                                    NULL);
+               if (error) {
+                       iput(inode);
+                       goto out;
+               }
+
                d_instantiate(dentry, inode);
                dget(dentry);   /* Extra count - pin the dentry in core */
                error = 0;
                inode_set_mtime_to_ts(dir, inode_set_ctime_current(dir));
        }
+out:
        return error;
 }
 
@@ -134,6 +143,15 @@ static int ramfs_symlink(struct mnt_idmap *idmap, struct inode *dir,
        inode = ramfs_get_inode(dir->i_sb, dir, S_IFLNK|S_IRWXUGO, 0);
        if (inode) {
                int l = strlen(symname)+1;
+
+               error = security_inode_init_security(inode, dir,
+                                                    &dentry->d_name, NULL,
+                                                    NULL);
+               if (error) {
+                       iput(inode);
+                       goto out;
+               }
+
                error = page_symlink(inode, symname, l);
                if (!error) {
                        d_instantiate(dentry, inode);
@@ -143,6 +161,7 @@ static int ramfs_symlink(struct mnt_idmap *idmap, struct inode *dir,
                } else
                        iput(inode);
        }
+out:
        return error;
 }
 
@@ -150,12 +169,23 @@ static int ramfs_tmpfile(struct mnt_idmap *idmap,
                         struct inode *dir, struct file *file, umode_t mode)
 {
        struct inode *inode;
+       int error;
 
        inode = ramfs_get_inode(dir->i_sb, dir, mode, 0);
        if (!inode)
                return -ENOSPC;
+
+       error = security_inode_init_security(inode, dir,
+                                            &file_dentry(file)->d_name, NULL,
+                                            NULL);
+       if (error) {
+               iput(inode);
+               goto out;
+       }
+
        d_tmpfile(file, inode);
-       return finish_open_simple(file, 0);
+out:
+       return finish_open_simple(file, error);
 }
 
 static const struct inode_operations ramfs_dir_inode_operations = {