diff --git a/fs/ext4/xattr.c b/fs/ext4/xattr.c
index 28d00ed833db..f0a45d3ec4eb 100644
--- a/fs/ext4/xattr.c
+++ b/fs/ext4/xattr.c
@@ -1384,6 +1384,12 @@ retry:
 			goto out;
 
 		memcpy(bh->b_data, buf, csize);
+		/*
+		 * Zero out block tail to avoid writing uninitialized memory
+		 * to disk.
+		 */
+		if (csize < blocksize)
+			memset(bh->b_data + csize, 0, blocksize - csize);
 		set_buffer_uptodate(bh);
 		ext4_handle_dirty_metadata(handle, ea_inode, bh);