Author: Balazs Benics Date: 2022-02-14T16:55:55+01:00 New Revision: bf5963bf19670ea58facdf57492e147c13bb650f
URL: https://github.com/llvm/llvm-project/commit/bf5963bf19670ea58facdf57492e147c13bb650f DIFF: https://github.com/llvm/llvm-project/commit/bf5963bf19670ea58facdf57492e147c13bb650f.diff LOG: [analyzer] Fix taint rule of fgets and setproctitle_init There was a typo in the rule. `{{0}, ReturnValueIndex}` meant that the discrete index is `0` and the variadic index is `-1`. What we wanted instead is that both `0` and `-1` are in the discrete index list. Instead of this, we wanted to express that both `0` and the `ReturnValueIndex` is in the discrete arg list. The manual inspection revealed that `setproctitle_init` also suffered a probably incomplete propagation rule. Reviewed By: Szelethus, gamesh411 Differential Revision: https://reviews.llvm.org/D119129 Added: Modified: clang/lib/StaticAnalyzer/Checkers/GenericTaintChecker.cpp clang/test/Analysis/taint-checker-callback-order-has-definition.c clang/test/Analysis/taint-checker-callback-order-without-definition.c clang/test/Analysis/taint-generic.c Removed: ################################################################################ diff --git a/clang/lib/StaticAnalyzer/Checkers/GenericTaintChecker.cpp b/clang/lib/StaticAnalyzer/Checkers/GenericTaintChecker.cpp index 66143f78932c..d15a4659a96e 100644 --- a/clang/lib/StaticAnalyzer/Checkers/GenericTaintChecker.cpp +++ b/clang/lib/StaticAnalyzer/Checkers/GenericTaintChecker.cpp @@ -559,7 +559,7 @@ void GenericTaintChecker::initTaintRules(CheckerContext &C) const { {{"atoll"}, TR::Prop({{0}}, {{ReturnValueIndex}})}, {{"fgetc"}, TR::Prop({{0}}, {{ReturnValueIndex}})}, {{"fgetln"}, TR::Prop({{0}}, {{ReturnValueIndex}})}, - {{"fgets"}, TR::Prop({{2}}, {{0}, ReturnValueIndex})}, + {{"fgets"}, TR::Prop({{2}}, {{0, ReturnValueIndex}})}, {{"fscanf"}, TR::Prop({{0}}, {{}, 2})}, {{"sscanf"}, TR::Prop({{0}}, {{}, 2})}, {{"getc"}, TR::Prop({{0}}, {{ReturnValueIndex}})}, @@ -632,7 +632,7 @@ void GenericTaintChecker::initTaintRules(CheckerContext &C) const { if (TR::UntrustedEnv(C)) { // void setproctitle_init(int argc, char *argv[], char *envp[]) GlobalCRules.push_back( - {{{"setproctitle_init"}}, TR::Sink({{2}}, MsgCustomSink)}); + {{{"setproctitle_init"}}, TR::Sink({{1, 2}}, MsgCustomSink)}); GlobalCRules.push_back({{"getenv"}, TR::Source({{ReturnValueIndex}})}); } diff --git a/clang/test/Analysis/taint-checker-callback-order-has-definition.c b/clang/test/Analysis/taint-checker-callback-order-has-definition.c index a070077004fa..cdf55e3aef41 100644 --- a/clang/test/Analysis/taint-checker-callback-order-has-definition.c +++ b/clang/test/Analysis/taint-checker-callback-order-has-definition.c @@ -25,11 +25,9 @@ void top(const char *fname, char *buf) { (void)fgets(buf, 42, fp); // Trigger taint propagation. // CHECK-NEXT: PreCall<fgets(buf, 42, fp)> prepares tainting arg index: -1 // CHECK-NEXT: PreCall<fgets(buf, 42, fp)> prepares tainting arg index: 0 - // CHECK-NEXT: PreCall<fgets(buf, 42, fp)> prepares tainting arg index: 1 // CHECK-NEXT: PreCall<fgets(buf, 42, fp)> prepares tainting arg index: 2 - + // // CHECK-NEXT: PostCall<fgets(buf, 42, fp)> actually wants to taint arg index: -1 // CHECK-NEXT: PostCall<fgets(buf, 42, fp)> actually wants to taint arg index: 0 - // CHECK-NEXT: PostCall<fgets(buf, 42, fp)> actually wants to taint arg index: 1 // CHECK-NEXT: PostCall<fgets(buf, 42, fp)> actually wants to taint arg index: 2 } diff --git a/clang/test/Analysis/taint-checker-callback-order-without-definition.c b/clang/test/Analysis/taint-checker-callback-order-without-definition.c index 962e8b259298..f2e070739e97 100644 --- a/clang/test/Analysis/taint-checker-callback-order-without-definition.c +++ b/clang/test/Analysis/taint-checker-callback-order-without-definition.c @@ -19,16 +19,11 @@ void top(const char *fname, char *buf) { (void)fgets(buf, 42, fp); // Trigger taint propagation. - // FIXME: Why is the arg index 1 prepared for taint? - // Before the call it wasn't tainted, and it also shouldn't be tainted after the call. - // CHECK-NEXT: PreCall<fgets(buf, 42, fp)> prepares tainting arg index: -1 // CHECK-NEXT: PreCall<fgets(buf, 42, fp)> prepares tainting arg index: 0 - // CHECK-NEXT: PreCall<fgets(buf, 42, fp)> prepares tainting arg index: 1 // CHECK-NEXT: PreCall<fgets(buf, 42, fp)> prepares tainting arg index: 2 // // CHECK-NEXT: PostCall<fgets(buf, 42, fp)> actually wants to taint arg index: -1 // CHECK-NEXT: PostCall<fgets(buf, 42, fp)> actually wants to taint arg index: 0 - // CHECK-NEXT: PostCall<fgets(buf, 42, fp)> actually wants to taint arg index: 1 // CHECK-NEXT: PostCall<fgets(buf, 42, fp)> actually wants to taint arg index: 2 } diff --git a/clang/test/Analysis/taint-generic.c b/clang/test/Analysis/taint-generic.c index 6979c0667764..0612e1b9f98b 100644 --- a/clang/test/Analysis/taint-generic.c +++ b/clang/test/Analysis/taint-generic.c @@ -58,9 +58,11 @@ extern FILE *stdin; #define bool _Bool +char *getenv(const char *name); int fscanf(FILE *restrict stream, const char *restrict format, ...); int sprintf(char *str, const char *format, ...); void setproctitle(const char *fmt, ...); +void setproctitle_init(int argc, char *argv[], char *envp[]); typedef __typeof(sizeof(int)) size_t; // Define string functions. Use builtin for some of them. They all default to @@ -404,3 +406,20 @@ void testConfigurationSinks(void) { void testUnknownFunction(void (*foo)(void)) { foo(); // no-crash } + +void testProctitleFalseNegative() { + char flag[80]; + fscanf(stdin, "%79s", flag); + char *argv[] = {"myapp", flag}; + // FIXME: We should have a warning below: Untrusted data passed to sink. + setproctitle_init(1, argv, 0); +} + +void testProctitle2(char *real_argv[]) { + char *app = getenv("APP_NAME"); + if (!app) + return; + char *argv[] = {app, "--foobar"}; + setproctitle_init(1, argv, 0); // expected-warning {{Untrusted data is passed to a user-defined sink}} + setproctitle_init(1, real_argv, argv); // expected-warning {{Untrusted data is passed to a user-defined sink}} +} _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
