1// SPDX-License-Identifier: GPL-2.0-only
  2/// Find uses of standard freeing functons on values allocated using devm_
  3/// functions.  Values allocated using the devm_functions are freed when
  4/// the device is detached, and thus the use of the standard freeing
  5/// function would cause a double free.
  6/// See Documentation/driver-api/driver-model/devres.rst for more information.
  7///
  8/// A difficulty of detecting this problem is that the standard freeing
  9/// function might be called from a different function than the one
 10/// containing the allocation function.  It is thus necessary to make the
 11/// connection between the allocation function and the freeing function.
 12/// Here this is done using the specific argument text, which is prone to
 13/// false positives.  There is no rule for the request_region and
 14/// request_mem_region variants because this heuristic seems to be a bit
 15/// less reliable in these cases.
 16///
 17// Confidence: Moderate
 18// Copyright: (C) 2011 Julia Lawall, INRIA/LIP6.
 19// Copyright: (C) 2011 Gilles Muller, INRIA/LiP6.
 20// URL: https://coccinelle.gitlabpages.inria.fr/website
 21// Comments:
 22// Options: --no-includes --include-headers
 23
 24virtual org
 25virtual report
 26virtual context
 27
 28@r depends on context || org || report@
 29expression x;
 30@@
 31
 32(
 33 x = devm_kmalloc(...)
 34|
 35 x = devm_kvasprintf(...)
 36|
 37 x = devm_kasprintf(...)
 38|
 39 x = devm_kzalloc(...)
 40|
 41 x = devm_kmalloc_array(...)
 42|
 43 x = devm_kcalloc(...)
 44|
 45 x = devm_kstrdup(...)
 46|
 47 x = devm_kmemdup(...)
 48|
 49 x = devm_get_free_pages(...)
 50|
 51 x = devm_request_irq(...)
 52|
 53 x = devm_ioremap(...)
 54|
 55 x = devm_ioport_map(...)
 56)
 57
 58@safe depends on context || org || report exists@
 59expression x;
 60position p;
 61@@
 62
 63(
 64 x = kmalloc(...)
 65|
 66 x = kvasprintf(...)
 67|
 68 x = kasprintf(...)
 69|
 70 x = kzalloc(...)
 71|
 72 x = kmalloc_array(...)
 73|
 74 x = kcalloc(...)
 75|
 76 x = kstrdup(...)
 77|
 78 x = kmemdup(...)
 79|
 80 x = get_free_pages(...)
 81|
 82 x = request_irq(...)
 83|
 84 x = ioremap(...)
 85|
 86 x = ioport_map(...)
 87)
 88...
 89(
 90 kfree@p(x)
 91|
 92 kfree_sensitive@p(x)
 93|
 94 krealloc@p(x, ...)
 95|
 96 free_pages@p(x, ...)
 97|
 98 free_page@p(x)
 99|
100 free_irq@p(x)
101|
102 iounmap@p(x)
103|
104 ioport_unmap@p(x)
105)
106
107@pb@
108expression r.x;
109position p != safe.p;
110@@
111
112(
113* kfree@p(x)
114|
115* kfree_sensitive@p(x)
116|
117* krealloc@p(x, ...)
118|
119* free_pages@p(x, ...)
120|
121* free_page@p(x)
122|
123* free_irq@p(x)
124|
125* iounmap@p(x)
126|
127* ioport_unmap@p(x)
128)
129
130@script:python depends on org@
131p << pb.p;
132@@
133
134msg="WARNING: invalid free of devm_ allocated data"
135coccilib.org.print_todo(p[0], msg)
136
137@script:python depends on report@
138p << pb.p;
139@@
140
141msg="WARNING: invalid free of devm_ allocated data"
142coccilib.report.print_report(p[0], msg)
143