Re: [PATCH] Workaround for ai_canonname sometimes coming back as null

From: Alex Riesen <raa.lkml@gmail.com>
Date: Apr 29, 2009, 21:55 UTC
Message-ID: <81b0412b0904291455n47f83e9ftcbdec0ff1c0ea03@mail.gmail.com>
In-Reply-To: <9C355DCC-0240-4B9E-83CA-083B51C2E34C@gmail.com>

2009/4/29 Augie Fackler <durin42@gmail.com>:

Show 11 quoted lines

> @@ -459,7 +459,10 @@ static void parse_extra_args(char *extra_args, int
> buflen)
>                                inet_ntop(AF_INET, &sin_addr->sin_addr,
>                                          addrbuf, sizeof(addrbuf));
>                                free(canon_hostname);
> -                               canon_hostname = xstrdup(ai->ai_canonname);
> +                               if (ai->ai_canonname)
> +                                       canon_hostname =
> xstrdup(ai->ai_canonname);
> +                               else
> +                                       canon_hostname = "unknown";

This last line will crash some lines down, when canon_hostname is free'd:

		inet_ntop(hent->h_addrtype, &sa.sin_addr,
			  addrbuf, sizeof(addrbuf));

		free(canon_hostname); /* CRASH */
		canon_hostname = xstrdup(hent->h_name);
		free(ip_address);