1 files changed, 100 insertions, 0 deletions
diff --git a/scripts/coccinelle/api/kfree_sensitive.cocci b/scripts/coccinelle/api/kfree_sensitive.cocci
new file mode 100644
index 000000000000..8d980ebf3223
--- /dev/null
+++ b/scripts/coccinelle/api/kfree_sensitive.cocci
@@ -0,0 +1,100 @@
+// SPDX-License-Identifier: GPL-2.0-only
+///
+/// Use kfree_sensitive, kvfree_sensitive rather than memset or
+/// memzero_explicit followed by kfree.
+///
+// Confidence: High
+// Copyright: (C) 2020 Denis Efremov ISPRAS
+// Options: --no-includes --include-headers
+//
+// Keywords: kfree_sensitive, kvfree_sensitive
+//
+
+virtual context
+virtual patch
+virtual org
+virtual report
+
+@initialize:python@
+@@
+# kmalloc_oob_in_memset uses memset to explicitly trigger out-of-bounds access
+filter = frozenset(['kmalloc_oob_in_memset',
+		    'kfree_sensitive', 'kvfree_sensitive'])
+
+def relevant(p):
+    return not (filter & {el.current_element for el in p})
+
+@cond@
+position ok;
+@@
+
+if (...)
+  \(memset@ok\|memzero_explicit@ok\)(...);
+
+@r depends on !patch forall@
+expression E;
+position p : script:python() { relevant(p) };
+position m != cond.ok;
+type T;
+@@
+
+(
+* memset@m((T)E, 0, ...);
+|
+* memzero_explicit@m((T)E, ...);
+)
+  ... when != E
+      when strict
+* \(kfree\|vfree\|kvfree\)(E)@p;
+
+@rp_memzero depends on patch@
+expression E, size;
+position p : script:python() { relevant(p) };
+position m != cond.ok;
+type T;
+@@
+
+- memzero_explicit@m((T)E, size);
+  ... when != E
+      when strict
+(
+- kfree(E)@p;
++ kfree_sensitive(E);
+|
+- \(vfree\|kvfree\)(E)@p;
++ kvfree_sensitive(E, size);
+)
+
+@rp_memset depends on patch@
+expression E, size;
+position p : script:python() { relevant(p) };
+position m != cond.ok;
+type T;
+@@
+
+- memset@m((T)E, 0, size);
+  ... when != E
+      when strict
+(
+- kfree(E)@p;
++ kfree_sensitive(E);
+|
+- \(vfree\|kvfree\)(E)@p;
++ kvfree_sensitive(E, size);
+)
+
+@script:python depends on report@
+p << r.p;
+m << r.m;
+@@
+
+msg = "WARNING opportunity for kfree_sensitive/kvfree_sensitive (memset at line %s)"
+coccilib.report.print_report(p[0], msg % (m[0].line))
+
+@script:python depends on org@
+p << r.p;
+m << r.m;
+@@
+
+msg = "WARNING opportunity for kfree_sensitive/kvfree_sensitive (memset at line %s)"
+coccilib.org.print_todo(p[0], msg % (m[0].line))