我怎么知道子进程是否正在等待 C 中的键盘输入

Question

I'm working on a buffer overflow exploitation in C (Linux). Goal of exploitation is to run shell as root .

So my strategy is like this.

1. Guess target address.
2. Run vulnerable program with #1's target address. (Run by fork-exec)
3. Check if the program is exploited. (whether shell is executed)
4. LOOP until #3 is satisfied.

My problem occurs from #3. How can I check if child process executes shell successfully?
Or, How can I know if child process is waiting for keyboard input?

Here is my code.

/*
GUESS TARGET_ADDRESS
*/
if(fork()==0){
    execl("./vulnerableProgram", "./vulnerableProgram", "exploitInput.txt", NULL);
}
int check = CHECK_IF_CHILD_PROCESS_RUNS_SHELL()          // <- here is my question
if(check) {
    printf("%s\n", TARGET_ADDRESS);
    break;
}

When child process fails to exploit, the status of child process is like below.

• Segmentation Fault
• Illegal Instructions
• exit normally (overflow doesn't occurs due to NULL character among the exploit code)

Answer 1

When a child terminates the program you enter to run it will return or exit normal with value or abnormal.I dont know what are you doing with exploitation and stuff but i can answer your to your question in how you know when the child executes shell successfully.You can tell the parent to wait for child until it's work is done and after you can handle normal or ubnormal execute by WIFEXITED(), if this return true means that execution of child was normal else abnormal.

waitpid(pid,&status,0);
if(WIFEXITED(status){
    printf("normal with %d", WEXITSTATUS(status));
}else{
  //abnormal
}