Prevent crash after mounting JFFS2 images built with incorrect erase size.

fs/jffs2/scan.c

@@ -7,7 +7,7 @@
  *
  * For licensing information, see the file 'LICENCE' in this directory.
  *
- * $Id: scan.c,v 1.78 2002/07/02 22:48:24 dwmw2 Exp $
+ * $Id: scan.c,v 1.79 2002/07/25 20:48:51 dwmw2 Exp $
  *
  */
 #include <linux/kernel.h>
@@ -322,6 +322,16 @@ static int jffs2_scan_eraseblock (struct jffs2_sb_info *c, struct jffs2_eraseblo
 			continue;
 		}
 
+		if (ofs + node.totlen > jeb->offset + c->sector_size) {
+			/* Eep. Node goes over the end of the erase block. */
+			printk(KERN_WARNING "Node at 0x%08x with length 0x%08x would run over the end of the erase block\n",
+			       ofs, node.totlen);
+			printk(KERN_WARNING "Perhaps the file system was created with the wrong erase size?\n");
+			DIRTY_SPACE(4);
+			ofs += 4;
+			continue;
+		}
+
 		if (!(node.nodetype & JFFS2_NODE_ACCURATE)) {
 			/* Wheee. This is an obsoleted node */
 			D2(printk(KERN_DEBUG "Node at 0x%08x is obsolete. Skipping\n", ofs));