Re: [bug-inetutils] ftpd segfault

[Simon Josefsson]

Michal Mazurek <address@hidden> writes:

> Run in the source dir:
> ./ftpd/ftpd -a default
>
> ftpd will segfault.
>
> OS is debian, linux 2.6.38-2-686.
>
> Please CC me when replying, I am not subscribed to this list.

Thank you for the report.  The cause is that arg is NULL here:

    case 'a':
      if (strcasecmp (arg, "default") == 0)
        cred.auth_type = AUTH_TYPE_PASSWD;
...
      break;

You may work around this by specifying 'ftpd -adefault' or 'ftpd
--auth=default' as suggested by the --help output.

Some observations:

1) The -a parameter is defined to only optionally take an option:

  { "auth", 'a', "AUTH", OPTION_ARG_OPTIONAL,
    "use AUTH for authentication",
    GRID+1 },

What's the point of this?

2) The '-a' parameter seems to be used for other things by BSD ftpd:

     -a      Give anonymous an other login-name (anonymous and ftpd will still
             work).

Do we have some parameter confusion here?

I believe the patch below should be applied.  It will solve the crash.
Thoughts?

/Simon

diff --git a/ftpd/ftpd.c b/ftpd/ftpd.c
index 29e9eed..bc31558 100644
--- a/ftpd/ftpd.c
+++ b/ftpd/ftpd.c
@@ -283,7 +283,7 @@ static struct argp_option options[] = {
   { "umask", 'u', "VAL", 0,
     "set default umask",
     GRID+1 },
-  { "auth", 'a', "AUTH", OPTION_ARG_OPTIONAL,
+  { "auth", 'a', "AUTH", 0,
     "use AUTH for authentication",
     GRID+1 },
   { NULL, 0, NULL, 0, "AUTH can be one of the following:", GRID+2 },