Author: Balazs Benics Date: 2021-10-28T11:03:02+02:00 New Revision: 49285f43e5ed17206235e43c9cd17762d77ed275
URL: https://github.com/llvm/llvm-project/commit/49285f43e5ed17206235e43c9cd17762d77ed275 DIFF: https://github.com/llvm/llvm-project/commit/49285f43e5ed17206235e43c9cd17762d77ed275.diff LOG: [analyzer] sprintf is a taint propagator not a source Due to a typo, `sprintf()` was recognized as a taint source instead of a taint propagator. It was because an empty taint source list - which is the first parameter of the `TaintPropagationRule` - encoded the unconditional taint sources. This typo effectively turned the `sprintf()` into an unconditional taint source. This patch fixes that typo and demonstrated the correct behavior with tests. Reviewed By: martong Differential Revision: https://reviews.llvm.org/D112558 Added: Modified: clang/lib/StaticAnalyzer/Checkers/GenericTaintChecker.cpp clang/test/Analysis/taint-generic.c Removed: ################################################################################ diff --git a/clang/lib/StaticAnalyzer/Checkers/GenericTaintChecker.cpp b/clang/lib/StaticAnalyzer/Checkers/GenericTaintChecker.cpp index 69e9cbd51c357..66ef781871ec9 100644 --- a/clang/lib/StaticAnalyzer/Checkers/GenericTaintChecker.cpp +++ b/clang/lib/StaticAnalyzer/Checkers/GenericTaintChecker.cpp @@ -514,7 +514,7 @@ GenericTaintChecker::TaintPropagationRule::getTaintPropagationRule( if (OneOf("snprintf")) return {{1}, {0, ReturnValueIndex}, VariadicType::Src, 3}; if (OneOf("sprintf")) - return {{}, {0, ReturnValueIndex}, VariadicType::Src, 2}; + return {{1}, {0, ReturnValueIndex}, VariadicType::Src, 2}; if (OneOf("strcpy", "stpcpy", "strcat")) return {{1}, {0, ReturnValueIndex}}; if (OneOf("bcopy")) diff --git a/clang/test/Analysis/taint-generic.c b/clang/test/Analysis/taint-generic.c index 2cbd580168ba9..90ab454ff7e8f 100644 --- a/clang/test/Analysis/taint-generic.c +++ b/clang/test/Analysis/taint-generic.c @@ -341,6 +341,16 @@ void constraintManagerShouldTreatAsOpaque(int rhs) { *(volatile int *) 0; // no-warning } +int sprintf_is_not_a_source(char *buf, char *msg) { + int x = sprintf(buf, "%s", msg); // no-warning + return 1 / x; // no-warning: 'sprintf' is not a taint source +} + +int sprintf_propagates_taint(char *buf, char *msg) { + scanf("%s", msg); + int x = sprintf(buf, "%s", msg); // propagate taint! + return 1 / x; // expected-warning {{Division by a tainted value, possibly zero}} +} // Test configuration int mySource1(); _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
