diff --git a/fs/jfs/jfs_dtree.c b/fs/jfs/jfs_dtree.c
index 8ce6e4458cc25..7b80c34e841db 100644
--- a/fs/jfs/jfs_dtree.c
+++ b/fs/jfs/jfs_dtree.c
@@ -2961,8 +2961,15 @@ int jfs_readdir(struct file *file, struct dir_context *ctx)
 			}
 
 			/* copy the name of head/only segment */
-			outlen = jfs_strfromUCS_le(name_ptr, d->name, len,
-						   codepage);
+			outlen = jfs_strfromUCS_le(name_ptr,
+						   (char *)dirent_buf +
+							   PAGE_SIZE - name_ptr,
+						   d->name, len, codepage);
+			if (outlen < 0) {
+				index = i;
+				overflow = 1;
+				break;
+			}
 			jfs_dirent->name_len = outlen;
 
 			/* copy name in the additional segment(s) */
@@ -2981,12 +2988,21 @@ int jfs_readdir(struct file *file, struct dir_context *ctx)
 					goto skip_one;
 				}
 				len = min(d_namleft, DTSLOTDATALEN);
-				outlen = jfs_strfromUCS_le(name_ptr, t->name,
-							   len, codepage);
+				outlen = jfs_strfromUCS_le(name_ptr,
+							   (char *)dirent_buf +
+								   PAGE_SIZE - name_ptr,
+							   t->name, len, codepage);
+				if (outlen < 0) {
+					index = i;
+					overflow = 1;
+					break;
+				}
 				jfs_dirent->name_len += outlen;
 
 				next = t->next;
 			}
+			if (overflow == 1)
+				break;
 
 			jfs_dirents++;
 			jfs_dirent = next_jfs_dirent(jfs_dirent);
diff --git a/fs/jfs/jfs_unicode.c b/fs/jfs/jfs_unicode.c
index 0c1e9027245a6..f73c718c5dd03 100644
--- a/fs/jfs/jfs_unicode.c
+++ b/fs/jfs/jfs_unicode.c
@@ -16,17 +16,25 @@
  * FUNCTION:	Convert little-endian unicode string to character string
  *
  */
-int jfs_strfromUCS_le(char *to, const __le16 * from,
+int jfs_strfromUCS_le(char *to, int to_size, const __le16 *from,
 		      int len, struct nls_table *codepage)
 {
-	int i;
+	int i, remaining_size;
 	int outlen = 0;
 	static int warn_again = 5;	/* Only warn up to 5 times total */
 	int warn = !!warn_again;	/* once per string */
 
+	if (to_size <= 0)
+		return -ENAMETOOLONG;
+
 	if (codepage) {
 		for (i = 0; (i < len) && from[i]; i++) {
 			int charlen;
+
+			remaining_size = to_size - outlen - 1;
+			if (remaining_size < NLS_MAX_CHARSET_SIZE)
+				return	-ENAMETOOLONG;
+
 			charlen =
 			    codepage->uni2char(le16_to_cpu(from[i]),
 					       &to[outlen],
@@ -38,6 +46,8 @@ int jfs_strfromUCS_le(char *to, const __le16 * from,
 		}
 	} else {
 		for (i = 0; (i < len) && from[i]; i++) {
+			if (i >= to_size - 1)
+				return -ENAMETOOLONG;
 			if (unlikely(le16_to_cpu(from[i]) & 0xff00)) {
 				to[i] = '?';
 				if (unlikely(warn)) {
diff --git a/fs/jfs/jfs_unicode.h b/fs/jfs/jfs_unicode.h
index b6a78d4aef1b0..ea03dd5a0e0cb 100644
--- a/fs/jfs/jfs_unicode.h
+++ b/fs/jfs/jfs_unicode.h
@@ -12,7 +12,7 @@
 #include "jfs_types.h"
 
 extern int get_UCSname(struct component_name *, struct dentry *);
-extern int jfs_strfromUCS_le(char *, const __le16 *, int, struct nls_table *);
+extern int jfs_strfromUCS_le(char *, int, const __le16 *, int, struct nls_table *);
 
 #define free_UCSname(COMP) kfree((COMP)->name)