fs: limit filesystem stacking depth

[sfrench/cifs-2.6.git] / fs / ecryptfs / main.c

diff --git a/fs/ecryptfs/main.c b/fs/ecryptfs/main.c
index 1b119d3bf924d16eea7f91f52449b122ecb5dcb1..c4cd1fd86cc2ffd4a09beddd3aca3f25d1fdb06f 100644 (file)
--- a/fs/ecryptfs/main.c
+++ b/fs/ecryptfs/main.c
@@ -566,6 +566,13 @@ static struct dentry *ecryptfs_mount(struct file_system_type *fs_type, int flags
        s->s_maxbytes = path.dentry->d_sb->s_maxbytes;
        s->s_blocksize = path.dentry->d_sb->s_blocksize;
        s->s_magic = ECRYPTFS_SUPER_MAGIC;
+       s->s_stack_depth = path.dentry->d_sb->s_stack_depth + 1;
+
+       rc = -EINVAL;
+       if (s->s_stack_depth > FILESYSTEM_MAX_STACK_DEPTH) {
+               pr_err("eCryptfs: maximum fs stacking depth exceeded\n");
+               goto out_free;
+       }
 
        inode = ecryptfs_get_inode(path.dentry->d_inode, s);
        rc = PTR_ERR(inode);