1 files changed, 119 insertions, 0 deletions
diff --git a/scripts/coccinelle/api/memdup_user.cocci b/scripts/coccinelle/api/memdup_user.cocci
new file mode 100644
index 000000000..03e7afa09
--- /dev/null
+++ b/scripts/coccinelle/api/memdup_user.cocci
@@ -0,0 +1,119 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/// 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.
+// Copyright: (C) 2010-2012 Julia Lawall, INRIA/LIP6.
+// Copyright: (C) 2010-2012 Gilles Muller, INRIA/LiP6.
+// URL: https://coccinelle.gitlabpages.inria.fr/website
+// Comments:
+// Options: --no-includes --include-headers
+
+virtual patch
+virtual context
+virtual org
+virtual report
+
+@initialize:python@
+@@
+filter = frozenset(['memdup_user', 'vmemdup_user'])
+
+def relevant(p):
+    return not (filter & {el.current_element for el in p})
+
+@depends on patch@
+expression from,to,size;
+identifier l1,l2;
+position p : script:python() { relevant(p) };
+@@
+
+-  to = \(kmalloc@p\|kzalloc@p\)
+-		(size,\(GFP_KERNEL\|GFP_USER\|
+-		      \(GFP_KERNEL\|GFP_USER\)|__GFP_NOWARN\));
++  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
+-    ...+>
+-  }
+
+@depends on patch@
+expression from,to,size;
+identifier l1,l2;
+position p : script:python() { relevant(p) };
+@@
+
+-  to = \(kvmalloc@p\|kvzalloc@p\)(size,\(GFP_KERNEL\|GFP_USER\));
++  to = vmemdup_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;
+position p : script:python() { relevant(p) };
+statement S1,S2;
+@@
+
+*  to = \(kmalloc@p\|kzalloc@p\)
+		(size,\(GFP_KERNEL\|GFP_USER\|
+		      \(GFP_KERNEL\|GFP_USER\)|__GFP_NOWARN\));
+   if (to==NULL || ...) S1
+   if (copy_from_user(to, from, size) != 0)
+   S2
+
+@rv depends on !patch@
+expression from,to,size;
+position p : script:python() { relevant(p) };
+statement S1,S2;
+@@
+
+*  to = \(kvmalloc@p\|kvzalloc@p\)(size,\(GFP_KERNEL\|GFP_USER\));
+   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")
+
+@script:python depends on org@
+p << rv.p;
+@@
+
+coccilib.org.print_todo(p[0], "WARNING opportunity for vmemdup_user")
+
+@script:python depends on report@
+p << rv.p;
+@@
+
+coccilib.report.print_report(p[0], "WARNING opportunity for vmemdup_user")