blob: 8ec226abf6a9c07d3ded7040f22913011a73fc02 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
|
//=== CastToStructChecker.cpp - Fixed address usage checker ----*- C++ -*--===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This files defines CastToStructChecker, a builtin checker that checks for
// cast from non-struct pointer to struct pointer.
// This check corresponds to CWE-588.
//
//===----------------------------------------------------------------------===//
#include "ClangSACheckers.h"
#include "clang/StaticAnalyzer/Core/CheckerManager.h"
#include "clang/StaticAnalyzer/Core/BugReporter/BugType.h"
#include "clang/StaticAnalyzer/Core/PathSensitive/CheckerVisitor.h"
using namespace clang;
using namespace ento;
namespace {
class CastToStructChecker
: public CheckerVisitor<CastToStructChecker> {
BuiltinBug *BT;
public:
CastToStructChecker() : BT(0) {}
static void *getTag();
void PreVisitCastExpr(CheckerContext &C, const CastExpr *B);
};
}
void *CastToStructChecker::getTag() {
static int x;
return &x;
}
void CastToStructChecker::PreVisitCastExpr(CheckerContext &C,
const CastExpr *CE) {
const Expr *E = CE->getSubExpr();
ASTContext &Ctx = C.getASTContext();
QualType OrigTy = Ctx.getCanonicalType(E->getType());
QualType ToTy = Ctx.getCanonicalType(CE->getType());
const PointerType *OrigPTy = dyn_cast<PointerType>(OrigTy.getTypePtr());
const PointerType *ToPTy = dyn_cast<PointerType>(ToTy.getTypePtr());
if (!ToPTy || !OrigPTy)
return;
QualType OrigPointeeTy = OrigPTy->getPointeeType();
QualType ToPointeeTy = ToPTy->getPointeeType();
if (!ToPointeeTy->isStructureOrClassType())
return;
// We allow cast from void*.
if (OrigPointeeTy->isVoidType())
return;
// Now the cast-to-type is struct pointer, the original type is not void*.
if (!OrigPointeeTy->isRecordType()) {
if (ExplodedNode *N = C.generateNode()) {
if (!BT)
BT = new BuiltinBug("Cast from non-struct type to struct type",
"Casting a non-structure type to a structure type "
"and accessing a field can lead to memory access "
"errors or data corruption.");
RangedBugReport *R = new RangedBugReport(*BT,BT->getDescription(), N);
R->addRange(CE->getSourceRange());
C.EmitReport(R);
}
}
}
static void RegisterCastToStructChecker(ExprEngine &Eng) {
Eng.registerCheck(new CastToStructChecker());
}
void ento::registerCastToStructChecker(CheckerManager &mgr) {
mgr.addCheckerRegisterFunction(RegisterCastToStructChecker);
}
|
