svn commit: r349896 - head/contrib/telnet/telnet

[Enji Cooper]

> On Jul 10, 2019, at 3:36 PM, Philip Paeps <philip at FreeBSD.org> wrote:
> 
> Author: philip
> Date: Wed Jul 10 22:36:14 2019
> New Revision: 349896
> URL: https://svnweb.freebsd.org/changeset/base/349896
> 
> Log:
>  telnet: fix minor style violation
> 
>  While here also fix a very unlikely NULL pointer dereference.
> 
>  Submitted by:	Shawn Webb <shawn.webb at hardenedbsd.org>
> 
> Modified:
>  head/contrib/telnet/telnet/commands.c
> 
> Modified: head/contrib/telnet/telnet/commands.c
> ==============================================================================
> --- head/contrib/telnet/telnet/commands.c	Wed Jul 10 22:23:59 2019	(r349895)
> +++ head/contrib/telnet/telnet/commands.c	Wed Jul 10 22:36:14 2019	(r349896)
> @@ -45,6 +45,7 @@ __FBSDID("$FreeBSD$");
> #include <sys/socket.h>
> #include <netinet/in.h>
> 
> +#include <assert.h>
> #include <ctype.h>
> #include <err.h>
> #include <errno.h>
> @@ -1654,11 +1655,13 @@ env_init(void)
> 		|| (strncmp((char *)ep->value, "unix:", 5) == 0))) {
> 		char hbuf[256+1];
> 		char *cp2 = strchr((char *)ep->value, ':');
> +                size_t buflen;
> 
> 		gethostname(hbuf, sizeof(hbuf));
> 		hbuf[sizeof(hbuf)-1] = '\0';
> -                unsigned int buflen = strlen(hbuf) + strlen(cp2) + 1;
> + 		buflen = strlen(hbuf) + strlen(cp2) + 1;
> 		cp = (char *)malloc(sizeof(char)*buflen);
> +		assert(cp != NULL);

This will unfortunately still segfault if assert is compiled out of the system as a no-op (-DNDEBUG).

I genuinely think using asprintf instead is the way to go, as Eitan and Warner brought up, since it reduces complexity in the program.

Thank you,
-Enji