do not run past the end of the disk!

[ cherry-picked de6075f ] Conflicts: fs.c
changaolin · Jun 24, 2011 · 96b7da5 · 96b7da5
1 parent f70ef99
commit 96b7da5
Showing 1 changed file with 1 addition and 1 deletion.
diff --git a/fs.c b/fs.c
@@ -61,7 +61,7 @@ balloc(uint dev)
   readsb(dev, &sb);
   for(b = 0; b < sb.size; b += BPB){
     bp = bread(dev, BBLOCK(b, sb.ninodes));
-    for(bi = 0; bi < BPB; bi++){
+    for(bi = 0; bi < BPB && bi < (sb.size - b); bi++){
       m = 1 << (bi % 8);
       if((bp->data[bi/8] & m) == 0){  // Is block free?
         bp->data[bi/8] |= m;  // Mark block in use on disk.