1 //==- CheckSecuritySyntaxOnly.cpp - Basic security checks --------*- C++ -*-==//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file defines a set of flow-insensitive security checks.
12 //===----------------------------------------------------------------------===//
14 #include "ClangSACheckers.h"
15 #include "clang/Analysis/AnalysisContext.h"
16 #include "clang/AST/StmtVisitor.h"
17 #include "clang/Basic/TargetInfo.h"
18 #include "clang/StaticAnalyzer/Core/Checker.h"
19 #include "clang/StaticAnalyzer/Core/BugReporter/BugReporter.h"
20 #include "clang/StaticAnalyzer/Core/PathSensitive/AnalysisManager.h"
21 #include "llvm/ADT/SmallString.h"
22 #include "llvm/ADT/StringSwitch.h"
23 #include "llvm/Support/raw_ostream.h"
25 using namespace clang;
28 static bool isArc4RandomAvailable(const ASTContext &Ctx) {
29 const llvm::Triple &T = Ctx.getTargetInfo().getTriple();
30 return T.getVendor() == llvm::Triple::Apple ||
31 T.getOS() == llvm::Triple::FreeBSD ||
32 T.getOS() == llvm::Triple::NetBSD ||
33 T.getOS() == llvm::Triple::OpenBSD ||
34 T.getOS() == llvm::Triple::DragonFly;
40 DefaultBool() : val(false) {}
41 operator bool() const { return val; }
42 DefaultBool &operator=(bool b) { val = b; return *this; }
46 DefaultBool check_gets;
47 DefaultBool check_getpw;
48 DefaultBool check_mktemp;
49 DefaultBool check_mkstemp;
50 DefaultBool check_strcpy;
51 DefaultBool check_rand;
52 DefaultBool check_vfork;
53 DefaultBool check_FloatLoopCounter;
54 DefaultBool check_UncheckedReturn;
57 class WalkAST : public StmtVisitor<WalkAST> {
59 AnalysisDeclContext* AC;
60 enum { num_setids = 6 };
61 IdentifierInfo *II_setid[num_setids];
64 const ChecksFilter &filter;
67 WalkAST(BugReporter &br, AnalysisDeclContext* ac,
68 const ChecksFilter &f)
69 : BR(br), AC(ac), II_setid(),
70 CheckRand(isArc4RandomAvailable(BR.getContext())),
73 // Statement visitor methods.
74 void VisitCallExpr(CallExpr *CE);
75 void VisitForStmt(ForStmt *S);
76 void VisitCompoundStmt (CompoundStmt *S);
77 void VisitStmt(Stmt *S) { VisitChildren(S); }
79 void VisitChildren(Stmt *S);
82 bool checkCall_strCommon(const CallExpr *CE, const FunctionDecl *FD);
84 typedef void (WalkAST::*FnCheck)(const CallExpr *,
85 const FunctionDecl *);
87 // Checker-specific methods.
88 void checkLoopConditionForFloat(const ForStmt *FS);
89 void checkCall_gets(const CallExpr *CE, const FunctionDecl *FD);
90 void checkCall_getpw(const CallExpr *CE, const FunctionDecl *FD);
91 void checkCall_mktemp(const CallExpr *CE, const FunctionDecl *FD);
92 void checkCall_mkstemp(const CallExpr *CE, const FunctionDecl *FD);
93 void checkCall_strcpy(const CallExpr *CE, const FunctionDecl *FD);
94 void checkCall_strcat(const CallExpr *CE, const FunctionDecl *FD);
95 void checkCall_rand(const CallExpr *CE, const FunctionDecl *FD);
96 void checkCall_random(const CallExpr *CE, const FunctionDecl *FD);
97 void checkCall_vfork(const CallExpr *CE, const FunctionDecl *FD);
98 void checkUncheckedReturnValue(CallExpr *CE);
100 } // end anonymous namespace
102 //===----------------------------------------------------------------------===//
104 //===----------------------------------------------------------------------===//
106 void WalkAST::VisitChildren(Stmt *S) {
107 for (Stmt::child_iterator I = S->child_begin(), E = S->child_end(); I!=E; ++I)
108 if (Stmt *child = *I)
112 void WalkAST::VisitCallExpr(CallExpr *CE) {
114 const FunctionDecl *FD = CE->getDirectCallee();
119 // Get the name of the callee. If it's a builtin, strip off the prefix.
120 IdentifierInfo *II = FD->getIdentifier();
121 if (!II) // if no identifier, not a simple C function
123 StringRef Name = II->getName();
124 if (Name.startswith("__builtin_"))
125 Name = Name.substr(10);
127 // Set the evaluation function by switching on the callee name.
128 FnCheck evalFunction = llvm::StringSwitch<FnCheck>(Name)
129 .Case("gets", &WalkAST::checkCall_gets)
130 .Case("getpw", &WalkAST::checkCall_getpw)
131 .Case("mktemp", &WalkAST::checkCall_mktemp)
132 .Case("mkstemp", &WalkAST::checkCall_mkstemp)
133 .Case("mkdtemp", &WalkAST::checkCall_mkstemp)
134 .Case("mkstemps", &WalkAST::checkCall_mkstemp)
135 .Cases("strcpy", "__strcpy_chk", &WalkAST::checkCall_strcpy)
136 .Cases("strcat", "__strcat_chk", &WalkAST::checkCall_strcat)
137 .Case("drand48", &WalkAST::checkCall_rand)
138 .Case("erand48", &WalkAST::checkCall_rand)
139 .Case("jrand48", &WalkAST::checkCall_rand)
140 .Case("lrand48", &WalkAST::checkCall_rand)
141 .Case("mrand48", &WalkAST::checkCall_rand)
142 .Case("nrand48", &WalkAST::checkCall_rand)
143 .Case("lcong48", &WalkAST::checkCall_rand)
144 .Case("rand", &WalkAST::checkCall_rand)
145 .Case("rand_r", &WalkAST::checkCall_rand)
146 .Case("random", &WalkAST::checkCall_random)
147 .Case("vfork", &WalkAST::checkCall_vfork)
150 // If the callee isn't defined, it is not of security concern.
151 // Check and evaluate the call.
153 (this->*evalFunction)(CE, FD);
155 // Recurse and check children.
159 void WalkAST::VisitCompoundStmt(CompoundStmt *S) {
160 for (Stmt::child_iterator I = S->child_begin(), E = S->child_end(); I!=E; ++I)
161 if (Stmt *child = *I) {
162 if (CallExpr *CE = dyn_cast<CallExpr>(child))
163 checkUncheckedReturnValue(CE);
168 void WalkAST::VisitForStmt(ForStmt *FS) {
169 checkLoopConditionForFloat(FS);
171 // Recurse and check children.
175 //===----------------------------------------------------------------------===//
176 // Check: floating poing variable used as loop counter.
177 // Originally: <rdar://problem/6336718>
178 // Implements: CERT security coding advisory FLP-30.
179 //===----------------------------------------------------------------------===//
181 static const DeclRefExpr*
182 getIncrementedVar(const Expr *expr, const VarDecl *x, const VarDecl *y) {
183 expr = expr->IgnoreParenCasts();
185 if (const BinaryOperator *B = dyn_cast<BinaryOperator>(expr)) {
186 if (!(B->isAssignmentOp() || B->isCompoundAssignmentOp() ||
187 B->getOpcode() == BO_Comma))
190 if (const DeclRefExpr *lhs = getIncrementedVar(B->getLHS(), x, y))
193 if (const DeclRefExpr *rhs = getIncrementedVar(B->getRHS(), x, y))
199 if (const DeclRefExpr *DR = dyn_cast<DeclRefExpr>(expr)) {
200 const NamedDecl *ND = DR->getDecl();
201 return ND == x || ND == y ? DR : NULL;
204 if (const UnaryOperator *U = dyn_cast<UnaryOperator>(expr))
205 return U->isIncrementDecrementOp()
206 ? getIncrementedVar(U->getSubExpr(), x, y) : NULL;
211 /// CheckLoopConditionForFloat - This check looks for 'for' statements that
212 /// use a floating point variable as a loop counter.
213 /// CERT: FLP30-C, FLP30-CPP.
215 void WalkAST::checkLoopConditionForFloat(const ForStmt *FS) {
216 if (!filter.check_FloatLoopCounter)
219 // Does the loop have a condition?
220 const Expr *condition = FS->getCond();
225 // Does the loop have an increment?
226 const Expr *increment = FS->getInc();
231 // Strip away '()' and casts.
232 condition = condition->IgnoreParenCasts();
233 increment = increment->IgnoreParenCasts();
235 // Is the loop condition a comparison?
236 const BinaryOperator *B = dyn_cast<BinaryOperator>(condition);
241 // Is this a comparison?
242 if (!(B->isRelationalOp() || B->isEqualityOp()))
245 // Are we comparing variables?
246 const DeclRefExpr *drLHS =
247 dyn_cast<DeclRefExpr>(B->getLHS()->IgnoreParenLValueCasts());
248 const DeclRefExpr *drRHS =
249 dyn_cast<DeclRefExpr>(B->getRHS()->IgnoreParenLValueCasts());
251 // Does at least one of the variables have a floating point type?
252 drLHS = drLHS && drLHS->getType()->isRealFloatingType() ? drLHS : NULL;
253 drRHS = drRHS && drRHS->getType()->isRealFloatingType() ? drRHS : NULL;
255 if (!drLHS && !drRHS)
258 const VarDecl *vdLHS = drLHS ? dyn_cast<VarDecl>(drLHS->getDecl()) : NULL;
259 const VarDecl *vdRHS = drRHS ? dyn_cast<VarDecl>(drRHS->getDecl()) : NULL;
261 if (!vdLHS && !vdRHS)
264 // Does either variable appear in increment?
265 const DeclRefExpr *drInc = getIncrementedVar(increment, vdLHS, vdRHS);
270 // Emit the error. First figure out which DeclRefExpr in the condition
271 // referenced the compared variable.
272 const DeclRefExpr *drCond = vdLHS == drInc->getDecl() ? drLHS : drRHS;
274 SmallVector<SourceRange, 2> ranges;
275 SmallString<256> sbuf;
276 llvm::raw_svector_ostream os(sbuf);
278 os << "Variable '" << drCond->getDecl()->getName()
279 << "' with floating point type '" << drCond->getType().getAsString()
280 << "' should not be used as a loop counter";
282 ranges.push_back(drCond->getSourceRange());
283 ranges.push_back(drInc->getSourceRange());
285 const char *bugType = "Floating point variable used as loop counter";
287 PathDiagnosticLocation FSLoc =
288 PathDiagnosticLocation::createBegin(FS, BR.getSourceManager(), AC);
289 BR.EmitBasicReport(AC->getDecl(),
290 bugType, "Security", os.str(),
291 FSLoc, ranges.data(), ranges.size());
294 //===----------------------------------------------------------------------===//
295 // Check: Any use of 'gets' is insecure.
296 // Originally: <rdar://problem/6335715>
297 // Implements (part of): 300-BSI (buildsecurityin.us-cert.gov)
298 // CWE-242: Use of Inherently Dangerous Function
299 //===----------------------------------------------------------------------===//
301 void WalkAST::checkCall_gets(const CallExpr *CE, const FunctionDecl *FD) {
302 if (!filter.check_gets)
305 const FunctionProtoType *FPT
306 = dyn_cast<FunctionProtoType>(FD->getType().IgnoreParens());
310 // Verify that the function takes a single argument.
311 if (FPT->getNumArgs() != 1)
314 // Is the argument a 'char*'?
315 const PointerType *PT = dyn_cast<PointerType>(FPT->getArgType(0));
319 if (PT->getPointeeType().getUnqualifiedType() != BR.getContext().CharTy)
323 SourceRange R = CE->getCallee()->getSourceRange();
324 PathDiagnosticLocation CELoc =
325 PathDiagnosticLocation::createBegin(CE, BR.getSourceManager(), AC);
326 BR.EmitBasicReport(AC->getDecl(),
327 "Potential buffer overflow in call to 'gets'",
329 "Call to function 'gets' is extremely insecure as it can "
330 "always result in a buffer overflow",
334 //===----------------------------------------------------------------------===//
335 // Check: Any use of 'getpwd' is insecure.
336 // CWE-477: Use of Obsolete Functions
337 //===----------------------------------------------------------------------===//
339 void WalkAST::checkCall_getpw(const CallExpr *CE, const FunctionDecl *FD) {
340 if (!filter.check_getpw)
343 const FunctionProtoType *FPT
344 = dyn_cast<FunctionProtoType>(FD->getType().IgnoreParens());
348 // Verify that the function takes two arguments.
349 if (FPT->getNumArgs() != 2)
352 // Verify the first argument type is integer.
353 if (!FPT->getArgType(0)->isIntegerType())
356 // Verify the second argument type is char*.
357 const PointerType *PT = dyn_cast<PointerType>(FPT->getArgType(1));
361 if (PT->getPointeeType().getUnqualifiedType() != BR.getContext().CharTy)
365 SourceRange R = CE->getCallee()->getSourceRange();
366 PathDiagnosticLocation CELoc =
367 PathDiagnosticLocation::createBegin(CE, BR.getSourceManager(), AC);
368 BR.EmitBasicReport(AC->getDecl(),
369 "Potential buffer overflow in call to 'getpw'",
371 "The getpw() function is dangerous as it may overflow the "
372 "provided buffer. It is obsoleted by getpwuid().",
376 //===----------------------------------------------------------------------===//
377 // Check: Any use of 'mktemp' is insecure. It is obsoleted by mkstemp().
378 // CWE-377: Insecure Temporary File
379 //===----------------------------------------------------------------------===//
381 void WalkAST::checkCall_mktemp(const CallExpr *CE, const FunctionDecl *FD) {
382 if (!filter.check_mktemp) {
383 // Fall back to the security check of looking for enough 'X's in the
384 // format string, since that is a less severe warning.
385 checkCall_mkstemp(CE, FD);
389 const FunctionProtoType *FPT
390 = dyn_cast<FunctionProtoType>(FD->getType().IgnoreParens());
394 // Verify that the function takes a single argument.
395 if (FPT->getNumArgs() != 1)
398 // Verify that the argument is Pointer Type.
399 const PointerType *PT = dyn_cast<PointerType>(FPT->getArgType(0));
403 // Verify that the argument is a 'char*'.
404 if (PT->getPointeeType().getUnqualifiedType() != BR.getContext().CharTy)
408 SourceRange R = CE->getCallee()->getSourceRange();
409 PathDiagnosticLocation CELoc =
410 PathDiagnosticLocation::createBegin(CE, BR.getSourceManager(), AC);
411 BR.EmitBasicReport(AC->getDecl(),
412 "Potential insecure temporary file in call 'mktemp'",
414 "Call to function 'mktemp' is insecure as it always "
415 "creates or uses insecure temporary file. Use 'mkstemp' "
421 //===----------------------------------------------------------------------===//
422 // Check: Use of 'mkstemp', 'mktemp', 'mkdtemp' should contain at least 6 X's.
423 //===----------------------------------------------------------------------===//
425 void WalkAST::checkCall_mkstemp(const CallExpr *CE, const FunctionDecl *FD) {
426 if (!filter.check_mkstemp)
429 StringRef Name = FD->getIdentifier()->getName();
430 std::pair<signed, signed> ArgSuffix =
431 llvm::StringSwitch<std::pair<signed, signed> >(Name)
432 .Case("mktemp", std::make_pair(0,-1))
433 .Case("mkstemp", std::make_pair(0,-1))
434 .Case("mkdtemp", std::make_pair(0,-1))
435 .Case("mkstemps", std::make_pair(0,1))
436 .Default(std::make_pair(-1, -1));
438 assert(ArgSuffix.first >= 0 && "Unsupported function");
440 // Check if the number of arguments is consistent with out expectations.
441 unsigned numArgs = CE->getNumArgs();
442 if ((signed) numArgs <= ArgSuffix.first)
445 const StringLiteral *strArg =
446 dyn_cast<StringLiteral>(CE->getArg((unsigned)ArgSuffix.first)
447 ->IgnoreParenImpCasts());
449 // Currently we only handle string literals. It is possible to do better,
450 // either by looking at references to const variables, or by doing real
452 if (!strArg || strArg->getCharByteWidth() != 1)
455 // Count the number of X's, taking into account a possible cutoff suffix.
456 StringRef str = strArg->getString();
458 unsigned n = str.size();
460 // Take into account the suffix.
462 if (ArgSuffix.second >= 0) {
463 const Expr *suffixEx = CE->getArg((unsigned)ArgSuffix.second);
465 if (!suffixEx->EvaluateAsInt(Result, BR.getContext()))
467 // FIXME: Issue a warning.
468 if (Result.isNegative())
470 suffix = (unsigned) Result.getZExtValue();
471 n = (n > suffix) ? n - suffix : 0;
474 for (unsigned i = 0; i < n; ++i)
475 if (str[i] == 'X') ++numX;
481 SourceRange R = strArg->getSourceRange();
482 PathDiagnosticLocation CELoc =
483 PathDiagnosticLocation::createBegin(CE, BR.getSourceManager(), AC);
484 SmallString<512> buf;
485 llvm::raw_svector_ostream out(buf);
486 out << "Call to '" << Name << "' should have at least 6 'X's in the"
487 " format string to be secure (" << numX << " 'X'";
492 out << ", " << suffix << " character";
495 out << " used as a suffix";
498 BR.EmitBasicReport(AC->getDecl(),
499 "Insecure temporary file creation", "Security",
500 out.str(), CELoc, &R, 1);
503 //===----------------------------------------------------------------------===//
504 // Check: Any use of 'strcpy' is insecure.
506 // CWE-119: Improper Restriction of Operations within
507 // the Bounds of a Memory Buffer
508 //===----------------------------------------------------------------------===//
509 void WalkAST::checkCall_strcpy(const CallExpr *CE, const FunctionDecl *FD) {
510 if (!filter.check_strcpy)
513 if (!checkCall_strCommon(CE, FD))
517 SourceRange R = CE->getCallee()->getSourceRange();
518 PathDiagnosticLocation CELoc =
519 PathDiagnosticLocation::createBegin(CE, BR.getSourceManager(), AC);
520 BR.EmitBasicReport(AC->getDecl(),
521 "Potential insecure memory buffer bounds restriction in "
524 "Call to function 'strcpy' is insecure as it does not "
525 "provide bounding of the memory buffer. Replace "
526 "unbounded copy functions with analogous functions that "
527 "support length arguments such as 'strlcpy'. CWE-119.",
531 //===----------------------------------------------------------------------===//
532 // Check: Any use of 'strcat' is insecure.
534 // CWE-119: Improper Restriction of Operations within
535 // the Bounds of a Memory Buffer
536 //===----------------------------------------------------------------------===//
537 void WalkAST::checkCall_strcat(const CallExpr *CE, const FunctionDecl *FD) {
538 if (!filter.check_strcpy)
541 if (!checkCall_strCommon(CE, FD))
545 SourceRange R = CE->getCallee()->getSourceRange();
546 PathDiagnosticLocation CELoc =
547 PathDiagnosticLocation::createBegin(CE, BR.getSourceManager(), AC);
548 BR.EmitBasicReport(AC->getDecl(),
549 "Potential insecure memory buffer bounds restriction in "
552 "Call to function 'strcat' is insecure as it does not "
553 "provide bounding of the memory buffer. Replace "
554 "unbounded copy functions with analogous functions that "
555 "support length arguments such as 'strlcat'. CWE-119.",
559 //===----------------------------------------------------------------------===//
560 // Common check for str* functions with no bounds parameters.
561 //===----------------------------------------------------------------------===//
562 bool WalkAST::checkCall_strCommon(const CallExpr *CE, const FunctionDecl *FD) {
563 const FunctionProtoType *FPT
564 = dyn_cast<FunctionProtoType>(FD->getType().IgnoreParens());
568 // Verify the function takes two arguments, three in the _chk version.
569 int numArgs = FPT->getNumArgs();
570 if (numArgs != 2 && numArgs != 3)
573 // Verify the type for both arguments.
574 for (int i = 0; i < 2; i++) {
575 // Verify that the arguments are pointers.
576 const PointerType *PT = dyn_cast<PointerType>(FPT->getArgType(i));
580 // Verify that the argument is a 'char*'.
581 if (PT->getPointeeType().getUnqualifiedType() != BR.getContext().CharTy)
588 //===----------------------------------------------------------------------===//
589 // Check: Linear congruent random number generators should not be used
590 // Originally: <rdar://problem/63371000>
591 // CWE-338: Use of cryptographically weak prng
592 //===----------------------------------------------------------------------===//
594 void WalkAST::checkCall_rand(const CallExpr *CE, const FunctionDecl *FD) {
595 if (!filter.check_rand || !CheckRand)
598 const FunctionProtoType *FTP
599 = dyn_cast<FunctionProtoType>(FD->getType().IgnoreParens());
603 if (FTP->getNumArgs() == 1) {
604 // Is the argument an 'unsigned short *'?
605 // (Actually any integer type is allowed.)
606 const PointerType *PT = dyn_cast<PointerType>(FTP->getArgType(0));
610 if (! PT->getPointeeType()->isIntegerType())
613 else if (FTP->getNumArgs() != 0)
617 SmallString<256> buf1;
618 llvm::raw_svector_ostream os1(buf1);
619 os1 << '\'' << *FD << "' is a poor random number generator";
621 SmallString<256> buf2;
622 llvm::raw_svector_ostream os2(buf2);
623 os2 << "Function '" << *FD
624 << "' is obsolete because it implements a poor random number generator."
625 << " Use 'arc4random' instead";
627 SourceRange R = CE->getCallee()->getSourceRange();
628 PathDiagnosticLocation CELoc =
629 PathDiagnosticLocation::createBegin(CE, BR.getSourceManager(), AC);
630 BR.EmitBasicReport(AC->getDecl(), os1.str(), "Security", os2.str(),
634 //===----------------------------------------------------------------------===//
635 // Check: 'random' should not be used
636 // Originally: <rdar://problem/63371000>
637 //===----------------------------------------------------------------------===//
639 void WalkAST::checkCall_random(const CallExpr *CE, const FunctionDecl *FD) {
640 if (!CheckRand || !filter.check_rand)
643 const FunctionProtoType *FTP
644 = dyn_cast<FunctionProtoType>(FD->getType().IgnoreParens());
648 // Verify that the function takes no argument.
649 if (FTP->getNumArgs() != 0)
653 SourceRange R = CE->getCallee()->getSourceRange();
654 PathDiagnosticLocation CELoc =
655 PathDiagnosticLocation::createBegin(CE, BR.getSourceManager(), AC);
656 BR.EmitBasicReport(AC->getDecl(),
657 "'random' is not a secure random number generator",
659 "The 'random' function produces a sequence of values that "
660 "an adversary may be able to predict. Use 'arc4random' "
661 "instead", CELoc, &R, 1);
664 //===----------------------------------------------------------------------===//
665 // Check: 'vfork' should not be used.
666 // POS33-C: Do not use vfork().
667 //===----------------------------------------------------------------------===//
669 void WalkAST::checkCall_vfork(const CallExpr *CE, const FunctionDecl *FD) {
670 if (!filter.check_vfork)
673 // All calls to vfork() are insecure, issue a warning.
674 SourceRange R = CE->getCallee()->getSourceRange();
675 PathDiagnosticLocation CELoc =
676 PathDiagnosticLocation::createBegin(CE, BR.getSourceManager(), AC);
677 BR.EmitBasicReport(AC->getDecl(),
678 "Potential insecure implementation-specific behavior in "
681 "Call to function 'vfork' is insecure as it can lead to "
682 "denial of service situations in the parent process. "
683 "Replace calls to vfork with calls to the safer "
684 "'posix_spawn' function",
688 //===----------------------------------------------------------------------===//
689 // Check: Should check whether privileges are dropped successfully.
690 // Originally: <rdar://problem/6337132>
691 //===----------------------------------------------------------------------===//
693 void WalkAST::checkUncheckedReturnValue(CallExpr *CE) {
694 if (!filter.check_UncheckedReturn)
697 const FunctionDecl *FD = CE->getDirectCallee();
701 if (II_setid[0] == NULL) {
702 static const char * const identifiers[num_setids] = {
703 "setuid", "setgid", "seteuid", "setegid",
704 "setreuid", "setregid"
707 for (size_t i = 0; i < num_setids; i++)
708 II_setid[i] = &BR.getContext().Idents.get(identifiers[i]);
711 const IdentifierInfo *id = FD->getIdentifier();
714 for (identifierid = 0; identifierid < num_setids; identifierid++)
715 if (id == II_setid[identifierid])
718 if (identifierid >= num_setids)
721 const FunctionProtoType *FTP
722 = dyn_cast<FunctionProtoType>(FD->getType().IgnoreParens());
726 // Verify that the function takes one or two arguments (depending on
728 if (FTP->getNumArgs() != (identifierid < 4 ? 1 : 2))
731 // The arguments must be integers.
732 for (unsigned i = 0; i < FTP->getNumArgs(); i++)
733 if (! FTP->getArgType(i)->isIntegerType())
737 SmallString<256> buf1;
738 llvm::raw_svector_ostream os1(buf1);
739 os1 << "Return value is not checked in call to '" << *FD << '\'';
741 SmallString<256> buf2;
742 llvm::raw_svector_ostream os2(buf2);
743 os2 << "The return value from the call to '" << *FD
744 << "' is not checked. If an error occurs in '" << *FD
745 << "', the following code may execute with unexpected privileges";
747 SourceRange R = CE->getCallee()->getSourceRange();
748 PathDiagnosticLocation CELoc =
749 PathDiagnosticLocation::createBegin(CE, BR.getSourceManager(), AC);
750 BR.EmitBasicReport(AC->getDecl(), os1.str(), "Security", os2.str(),
754 //===----------------------------------------------------------------------===//
755 // SecuritySyntaxChecker
756 //===----------------------------------------------------------------------===//
759 class SecuritySyntaxChecker : public Checker<check::ASTCodeBody> {
763 void checkASTCodeBody(const Decl *D, AnalysisManager& mgr,
764 BugReporter &BR) const {
765 WalkAST walker(BR, mgr.getAnalysisDeclContext(D), filter);
766 walker.Visit(D->getBody());
771 #define REGISTER_CHECKER(name) \
772 void ento::register##name(CheckerManager &mgr) {\
773 mgr.registerChecker<SecuritySyntaxChecker>()->filter.check_##name = true;\
776 REGISTER_CHECKER(gets)
777 REGISTER_CHECKER(getpw)
778 REGISTER_CHECKER(mkstemp)
779 REGISTER_CHECKER(mktemp)
780 REGISTER_CHECKER(strcpy)
781 REGISTER_CHECKER(rand)
782 REGISTER_CHECKER(vfork)
783 REGISTER_CHECKER(FloatLoopCounter)
784 REGISTER_CHECKER(UncheckedReturn)