diff --git a/fs/cifs/readdir.c b/fs/cifs/readdir.c
index f9b5d3d6cf33461081f4945d61a5d604fe2ef468..1c576e8713669534be76853aa6c45e97482def96 100644
--- a/fs/cifs/readdir.c
+++ b/fs/cifs/readdir.c
@@ -86,14 +86,17 @@ cifs_readdir_lookup(struct dentry *parent, struct qstr *name,
 
 	dentry = d_lookup(parent, name);
 	if (dentry) {
+		int err;
 		inode = dentry->d_inode;
 		/* update inode in place if i_ino didn't change */
 		if (inode && CIFS_I(inode)->uniqueid == fattr->cf_uniqueid) {
 			cifs_fattr_to_inode(inode, fattr);
 			return dentry;
 		}
-		d_drop(dentry);
+		err = d_invalidate(dentry);
 		dput(dentry);
+		if (err)
+			return NULL;
 	}
 
 	dentry = d_alloc(parent, name);
diff --git a/fs/file.c b/fs/file.c
index 7cb71b99260340fe7302d2a8c5dc4f84f8029aff..eff23162485f93176255199b3ed74176534ae489 100644
--- a/fs/file.c
+++ b/fs/file.c
@@ -994,16 +994,18 @@ int iterate_fd(struct files_struct *files, unsigned n,
 		const void *p)
 {
 	struct fdtable *fdt;
-	struct file *file;
 	int res = 0;
 	if (!files)
 		return 0;
 	spin_lock(&files->file_lock);
-	fdt = files_fdtable(files);
-	while (!res && n < fdt->max_fds) {
-		file = rcu_dereference_check_fdtable(files, fdt->fd[n++]);
-		if (file)
-			res = f(p, file, n);
+	for (fdt = files_fdtable(files); n < fdt->max_fds; n++) {
+		struct file *file;
+		file = rcu_dereference_check_fdtable(files, fdt->fd[n]);
+		if (!file)
+			continue;
+		res = f(p, file, n);
+		if (res)
+			break;
 	}
 	spin_unlock(&files->file_lock);
 	return res;
diff --git a/fs/namei.c b/fs/namei.c
index 937f9d50c84bdead7516057fead3d5a702ead4b9..5f4cdf3ad913fec928835d87fbe499efdf7d67e5 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -2131,6 +2131,11 @@ struct dentry *lookup_one_len(const char *name, struct dentry *base, int len)
 	if (!len)
 		return ERR_PTR(-EACCES);
 
+	if (unlikely(name[0] == '.')) {
+		if (len < 2 || (len == 2 && name[1] == '.'))
+			return ERR_PTR(-EACCES);
+	}
+
 	while (len--) {
 		c = *(const unsigned char *)name++;
 		if (c == '/' || c == '\0')
diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
index ce8cb926526bfad79aabe5b8448f80212e1670f9..b9e66b7e0c1495ba05c1fb6a4b2f1557ca6a9b24 100644
--- a/fs/nfs/dir.c
+++ b/fs/nfs/dir.c
@@ -450,7 +450,8 @@ void nfs_prime_dcache(struct dentry *parent, struct nfs_entry *entry)
 			nfs_refresh_inode(dentry->d_inode, entry->fattr);
 			goto out;
 		} else {
-			d_drop(dentry);
+			if (d_invalidate(dentry) != 0)
+				goto out;
 			dput(dentry);
 		}
 	}
@@ -1100,6 +1101,8 @@ static int nfs_lookup_revalidate(struct dentry *dentry, unsigned int flags)
 out_zap_parent:
 	nfs_zap_caches(dir);
  out_bad:
+	nfs_free_fattr(fattr);
+	nfs_free_fhandle(fhandle);
 	nfs_mark_for_revalidate(dir);
 	if (inode && S_ISDIR(inode->i_mode)) {
 		/* Purge readdir caches. */
@@ -1112,8 +1115,6 @@ static int nfs_lookup_revalidate(struct dentry *dentry, unsigned int flags)
 		shrink_dcache_parent(dentry);
 	}
 	d_drop(dentry);
-	nfs_free_fattr(fattr);
-	nfs_free_fhandle(fhandle);
 	dput(parent);
 	dfprintk(LOOKUPCACHE, "NFS: %s(%s/%s) is invalid\n",
 			__func__, dentry->d_parent->d_name.name,