| 1 | //===-- CommandProcessorCheck.cpp - clang-tidy ----------------------------===// |
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| 2 | // |
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| 3 | // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
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| 4 | // See https://llvm.org/LICENSE.txt for license information. |
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| 5 | // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
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| 6 | // |
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| 7 | //===----------------------------------------------------------------------===// |
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| 8 | |
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| 9 | #include "CommandProcessorCheck.h" |
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| 10 | #include "clang/AST/ASTContext.h" |
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| 11 | #include "clang/ASTMatchers/ASTMatchFinder.h" |
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| 12 | |
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| 13 | using namespace clang::ast_matchers; |
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| 14 | |
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| 15 | namespace clang::tidy::cert { |
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| 16 | |
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| 17 | void CommandProcessorCheck::registerMatchers(MatchFinder *Finder) { |
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| 18 | Finder->addMatcher( |
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| 19 | NodeMatch: callExpr( |
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| 20 | callee(InnerMatcher: functionDecl(hasAnyName("::system" , "::popen" , "::_popen" )) |
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| 21 | .bind(ID: "func" )), |
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| 22 | // Do not diagnose when the call expression passes a null pointer |
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| 23 | // constant to system(); that only checks for the presence of a |
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| 24 | // command processor, which is not a security risk by itself. |
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| 25 | unless(callExpr(callee(InnerMatcher: functionDecl(hasName(Name: "::system" ))), |
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| 26 | argumentCountIs(N: 1), |
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| 27 | hasArgument(N: 0, InnerMatcher: nullPointerConstant())))) |
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| 28 | .bind(ID: "expr" ), |
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| 29 | Action: this); |
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| 30 | } |
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| 31 | |
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| 32 | void CommandProcessorCheck::check(const MatchFinder::MatchResult &Result) { |
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| 33 | const auto *Fn = Result.Nodes.getNodeAs<FunctionDecl>(ID: "func" ); |
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| 34 | const auto *E = Result.Nodes.getNodeAs<CallExpr>(ID: "expr" ); |
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| 35 | |
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| 36 | diag(E->getExprLoc(), "calling %0 uses a command processor" ) << Fn; |
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| 37 | } |
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| 38 | |
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| 39 | } // namespace clang::tidy::cert |
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| 40 | |
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