Viktor Dukhovni:
> On Wed, Sep 22, 2021 at 10:35:45PM +1000, raf wrote:
>
> > I just encountered a wierd thing (debian-11 stable, postfix-3.5.6-1+b1).
>
> Thanks for the bug report.
>
> > $ postconf -xdf proxy_read_maps
> > proxy_read_maps = all127.0.0.0/8 a.b.c.d/32 [::1]/128
> > [a:b:c:d::e]/128 [fe80::]/64 hash:/etc/aliases, nis:mail.aliases
>
> The problem is an recursive reuse of a static buffer in the postconf(1)
> code (does not affect any other Postfix programs, ...) that expands the
> default value of mynetworks, when called recursively from expanding some
> other parameter.
>
> Patch below.
Thanks. This is the result of lazy coding in a nasty language.
I should stop hidden static buffers, or switch to a language
has automatic destructors like C++ or Go.
Wietse
> --
> Viktor.
>
> --- a/src/postconf/postconf_builtin.c
> +++ b/src/postconf/postconf_builtin.c
> @@ -250,6 +250,7 @@ static const char *pcf_check_mydomainname(void)
> static const char *pcf_mynetworks(void)
> {
> static const char *networks;
> + static VSTRING *local_buf;
> const char *junk;
>
> /*
> @@ -258,10 +259,13 @@ static const char *pcf_mynetworks(void)
> if (networks)
> return (networks);
>
> + if (local_buf == 0)
> + local_buf = vstring_alloc(100);
> +
> if (var_inet_interfaces == 0) {
> if ((pcf_cmd_mode & PCF_SHOW_DEFS)
> || (junk = mail_conf_lookup_eval(VAR_INET_INTERFACES)) == 0)
> - junk = pcf_expand_parameter_value((VSTRING *) 0, pcf_cmd_mode,
> + junk = pcf_expand_parameter_value(local_buf, pcf_cmd_mode,
> DEF_INET_INTERFACES,
> (PCF_MASTER_ENT *) 0);
> var_inet_interfaces = mystrdup(junk);
> @@ -269,7 +273,7 @@ static const char *pcf_mynetworks(void)
> if (var_mynetworks_style == 0) {
> if ((pcf_cmd_mode & PCF_SHOW_DEFS)
> || (junk = mail_conf_lookup_eval(VAR_MYNETWORKS_STYLE)) == 0)
> - junk = pcf_expand_parameter_value((VSTRING *) 0, pcf_cmd_mode,
> + junk = pcf_expand_parameter_value(local_buf, pcf_cmd_mode,
> DEF_MYNETWORKS_STYLE,
> (PCF_MASTER_ENT *) 0);
> var_mynetworks_style = mystrdup(junk);
> @@ -277,7 +281,7 @@ static const char *pcf_mynetworks(void)
> if (var_inet_protocols == 0) {
> if ((pcf_cmd_mode & PCF_SHOW_DEFS)
> || (junk = mail_conf_lookup_eval(VAR_INET_PROTOCOLS)) == 0)
> - junk = pcf_expand_parameter_value((VSTRING *) 0, pcf_cmd_mode,
> + junk = pcf_expand_parameter_value(local_buf, pcf_cmd_mode,
> DEF_INET_PROTOCOLS,
> (PCF_MASTER_ENT *) 0);
> var_inet_protocols = mystrdup(junk);
>
