/scripts/coccinelle/api/memdup_user.cocci

 1/// Use memdup_user rather than duplicating its implementation
 2/// This is a little bit restricted to reduce false positives
 3///
 4// Confidence: High
 5// Copyright: (C) 2010-2012 Nicolas Palix.  GPLv2.
 6// Copyright: (C) 2010-2012 Julia Lawall, INRIA/LIP6.  GPLv2.
 7// Copyright: (C) 2010-2012 Gilles Muller, INRIA/LiP6.  GPLv2.
 8// URL: http://coccinelle.lip6.fr/
 9// Comments:
10// Options: --no-includes --include-headers
11
12virtual patch
13virtual context
14virtual org
15virtual report
16
17@depends on patch@
18expression from,to,size,flag;
19identifier l1,l2;
20@@
21
22-  to = \(kmalloc\|kzalloc\)(size,flag);
23+  to = memdup_user(from,size);
24   if (
25-      to==NULL
26+      IS_ERR(to)
27                 || ...) {
28   <+... when != goto l1;
29-  -ENOMEM
30+  PTR_ERR(to)
31   ...+>
32   }
33-  if (copy_from_user(to, from, size) != 0) {
34-    <+... when != goto l2;
35-    -EFAULT
36-    ...+>
37-  }
38
39@r depends on !patch@
40expression from,to,size,flag;
41position p;
42statement S1,S2;
43@@
44
45*  to = \(kmalloc@p\|kzalloc@p\)(size,flag);
46   if (to==NULL || ...) S1
47   if (copy_from_user(to, from, size) != 0)
48   S2
49
50@script:python depends on org@
51p << r.p;
52@@
53
54coccilib.org.print_todo(p[0], "WARNING opportunity for memdup_user")
55
56@script:python depends on report@
57p << r.p;
58@@
59
60coccilib.report.print_report(p[0], "WARNING opportunity for memdup_user")