SV.FMT_STR.PRINT_PARAMS_WRONGNUM.MANY

Too many arguments in print function call

In a format string in a print function call, there should be the same number of parameters as there are format specifications. The SV.FMT_STR.PRINT_PARAMS_WRONGNUM.MANY checker flags the code if there are more parameters provided to the print function than specified in the format string.

Vulnerability and risk

When the syntax of the conversion specification is incorrect, the resulting behavior is undefined, and it may cause unexpected output.

Vulnerable code example

1  void foo(FILE* f, char* pc, int i, char c) {
2      fprintf(f, "%o", i, pc);    
3      fprintf(f, "%p", pc);
4  }

Klocwork reports an error for line 2. Since there should be the same number of specifications and corresponding parameters in the format string, the function is expecting only one parameter for the %o specification, and receives two. Line 3 isn't flagged, since the format string has one specification and one corresponding parameter.

Fixed code example

1  void foo(FILE* f, char* pc, int i, char c) {
2      fprintf(f, "%o", i);    
3      fprintf(f, "%p", pc);
4  }

In the fixed example, line 2 has one specifications and one corresponding parameter.