scripts/coccinelle/api/memdup_user.cocci

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /// Use memdup_user rather than duplicating its implementation
   3 /// This is a little bit restricted to reduce false positives
   4 ///
   5 // Confidence: High
   6 // Copyright: (C) 2010-2012 Nicolas Palix.
   7 // Copyright: (C) 2010-2012 Julia Lawall, INRIA/LIP6.
   8 // Copyright: (C) 2010-2012 Gilles Muller, INRIA/LiP6.
   9 // URL: http://coccinelle.lip6.fr/
  10 // Comments:
  11 // Options: --no-includes --include-headers
  12
  13 virtual patch
  14 virtual context
  15 virtual org
  16 virtual report
  17
  18 @depends on patch@
  19 expression from,to,size;
  20 identifier l1,l2;
  21 @@
  22
  23 -  to = \(kmalloc\|kzalloc\)(size,GFP_KERNEL);
  24 +  to = memdup_user(from,size);
  25    if (
  26 -      to==NULL
  27 +      IS_ERR(to)
  28                  || ...) {
  29    <+... when != goto l1;
  30 -  -ENOMEM
  31 +  PTR_ERR(to)
  32    ...+>
  33    }
  34 -  if (copy_from_user(to, from, size) != 0) {
  35 -    <+... when != goto l2;
  36 -    -EFAULT
  37 -    ...+>
  38 -  }
  39
  40 @r depends on !patch@
  41 expression from,to,size;
  42 position p;
  43 statement S1,S2;
  44 @@
  45
  46 *  to = \(kmalloc@p\|kzalloc@p\)(size,GFP_KERNEL);
  47    if (to==NULL || ...) S1
  48    if (copy_from_user(to, from, size) != 0)
  49    S2
  50
  51 @script:python depends on org@
  52 p << r.p;
  53 @@
  54
  55 coccilib.org.print_todo(p[0], "WARNING opportunity for memdup_user")
  56
  57 @script:python depends on report@
  58 p << r.p;
  59 @@
  60
  61 coccilib.report.print_report(p[0], "WARNING opportunity for memdup_user")