namei: we never need more than MAXSYMLINKS entries in nd->stack
authorAl Viro <viro@zeniv.linux.org.uk>
Mon, 4 May 2015 01:30:27 +0000 (21:30 -0400)
committerAl Viro <viro@zeniv.linux.org.uk>
Mon, 11 May 2015 02:20:08 +0000 (22:20 -0400)
The only reason why we needed one more was that purely nested
MAXSYMLINKS symlinks could lead to path_init() using that many
entries in addition to nd->stack[0] which it left unused.

That can't happen now - path_init() starts with entry 0 (and
trailing_symlink() is called only when we'd already encountered
one symlink, so no more than MAXSYMLINKS-1 are left).

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
fs/namei.c

index d12b16c13f0c77f97f9c11bc96f6649df0ee3af6..b939f488bc6fe0b9cda5291aa28163c148594601 100644 (file)
@@ -528,7 +528,7 @@ static void restore_nameidata(struct nameidata *nd)
 
 static int __nd_alloc_stack(struct nameidata *nd)
 {
-       struct saved *p = kmalloc((MAXSYMLINKS + 1) * sizeof(struct saved),
+       struct saved *p = kmalloc(MAXSYMLINKS * sizeof(struct saved),
                                  GFP_KERNEL);
        if (unlikely(!p))
                return -ENOMEM;