Boundary tests for filename/pathname

[Steve Grubb]

On Tuesday 07 June 2005 18:58, Loulwa Salem wrote:
> Then I thought to get the latest audit and I look in auditctl.c file, it
> seems that it is comparing against strlen() output, so not counting NULL.

Hmm. Fixing this.

> Based on what I found, I am thinking my initial assumption above is not
> valid, and I need to supply enough characters (without the null) to meet
> my test scenario ... Is this correct?

The authoritative place, as far as I know, is /usr/include/linux/limits.h.

#define PATH_MAX        4096    /* # chars in a path name including nul */

So...auditctl was letting strings 1 byte too big through. It now does:

        size_t len = strlen(path);
        if (len >= PATH_MAX) {
                fprintf(stderr, "The path passed for the watch is too big\n");
                return 1;
        }

The kernel should have complained about this as well. auditfs.c 
audit_receive_watch should be changed as well:

      if (req->pathlen == 0)
              goto audit_receive_watch_exit;

      if (req->pathlen >= PATH_MAX) {
              ret = -ENAMETOOLONG;
              goto audit_receive_watch_exit;
      }

-Steve