/// Use memdup_user rather than duplicating its implementation
/// This is a little bit restricted to reduce false positives
///
// Confidence: High
// Copyright: (C) 2010-2012 Nicolas Palix. GPLv2.
// Copyright: (C) 2010-2012 Julia Lawall, INRIA/LIP6. GPLv2.
// Copyright: (C) 2010-2012 Gilles Muller, INRIA/LiP6. GPLv2.
// URL: http://coccinelle.lip6.fr/
// Comments:
// Options: --no-includes --include-headers

virtual patch
virtual context
virtual org
virtual report

@depends on patch@
expression from,to,size,flag;
identifier l1,l2;
@@

- to = \(kmalloc\|kzalloc\)(size,flag);
+ to = memdup_user(from,size);
if (
- to==NULL
+ IS_ERR(to)
|| ...) {
<+... when != goto l1;
- -ENOMEM
+ PTR_ERR(to)
...+>
}
- if (copy_from_user(to, from, size) != 0) {
- <+... when != goto l2;
- -EFAULT
- ...+>
- }

@r depends on !patch@
expression from,to,size,flag;
position p;
statement S1,S2;
@@

* to = \(kmalloc@p\|kzalloc@p\)(size,flag);
if (to==NULL || ...) S1
if (copy_from_user(to, from, size) != 0)
S2

@script:python depends on org@
p << r.p;
@@

coccilib.org.print_todo(p[0], "WARNING opportunity for memdup_user")

@script:python depends on report@
p << r.p;
@@

coccilib.report.print_report(p[0], "WARNING opportunity for memdup_user")