fix(fprintf): Too few arguments to formatting function

[opsysdebug]

Problem

Each call to the printf function, or a related function, should include the number of arguments defined by the format. Passing the function more arguments than required is harmless (although it may be indicative of other defects). However, passing the function fewer arguments than are defined by the format can be a security vulnerability since the function will process the next item on the stack as the missing arguments. This might lead to an information leak if a sensitive value from the stack is printed. It might cause a crash if a value on the stack is interpreted as a pointer and leads to accessing unmapped memory. Finally, it may lead to a follow-on vulnerability if an attacker can use this problem to cause the output string to be too long or have unexpected contents.

fix the issue, ensure that the fprintf call provides the correct number of arguments to match the format string. The format string "%X/%X\n" expects two arguments, so the macro LSN_FORMAT_ARGS(lsn) must expand to two values. If the macro already provides two values (e.g., a pair of integers), the issue might be with how it is used. If the macro only provides one value, it needs to be replaced or expanded to provide the required two arguments.

The fix involves verifying the definition of LSN_FORMAT_ARGS and ensuring it provides two arguments. If it does, the fprintf call should be updated to correctly unpack and pass those arguments. If it does not, the macro or the code using it must be adjusted to supply the missing argument.

int main() {
  printf("%d, %s\n", 42); // Will crash or print garbage
  return 0;
}

References

CERT C Coding Standard: FIO47-C. Use valid format strings
Microsoft C Runtime Library Reference: printf, wprintf

[hlinnaka]

This is a low-effort AI-generated report. It's also incorrect in many ways. Please don't do that here.