Author: serge-sans-paille Date: 2022-09-05T10:54:18+02:00 New Revision: ab09043a1985bfb9f1e4393a29a9d83326d306fe
URL: https://github.com/llvm/llvm-project/commit/ab09043a1985bfb9f1e4393a29a9d83326d306fe DIFF: https://github.com/llvm/llvm-project/commit/ab09043a1985bfb9f1e4393a29a9d83326d306fe.diff LOG: [clang] Fix crash when parsing scanf format string with missing arguments When parsing a format string with less argument than specified, one should check argument access because there may be no such argument. This fixes #57517 Differential Revision: https://reviews.llvm.org/D133197 Added: Modified: clang/lib/Sema/SemaChecking.cpp clang/test/Sema/format-strings-scanf.c Removed: ################################################################################ diff --git a/clang/lib/Sema/SemaChecking.cpp b/clang/lib/Sema/SemaChecking.cpp index 897ab701493c2..afe99ad24fb9d 100644 --- a/clang/lib/Sema/SemaChecking.cpp +++ b/clang/lib/Sema/SemaChecking.cpp @@ -1066,6 +1066,9 @@ void Sema::checkFortifiedBuiltinMemoryFunction(FunctionDecl *FD, return llvm::None; unsigned NewIndex = *IndexOptional; + if (NewIndex >= TheCall->getNumArgs()) + return llvm::None; + const Expr *ObjArg = TheCall->getArg(NewIndex); uint64_t Result; if (!ObjArg->tryEvaluateObjectSize(Result, getASTContext(), BOSType)) diff --git a/clang/test/Sema/format-strings-scanf.c b/clang/test/Sema/format-strings-scanf.c index aebb68c37fb98..eb5b8ec36bf7a 100644 --- a/clang/test/Sema/format-strings-scanf.c +++ b/clang/test/Sema/format-strings-scanf.c @@ -69,6 +69,11 @@ void bad_length_modifiers(char *s, void *p, wchar_t *ws, long double *ld) { scanf("%#.2Lf", ld); // expected-warning{{invalid conversion specifier '#'}} } +void missing_argument_with_length_modifier() { + char buf[30]; + scanf("%s:%900s", buf); // expected-warning{{more '%' conversions than data arguments}} +} + // Test that the scanf call site is where the warning is attached. If the // format string is somewhere else, point to it in a note. void pr9751(void) { _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
