dhcpcd-discuss

I upgraded dhcpcd and it consistently failed to start up.  I tracked the
problem down to a '\0' being added beyond the allocated memory.  There's
a simple patch:

> ---
>  src/if-options.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/src/if-options.c b/src/if-options.c
> index f3f12316..6bf4ad04 100644
> --- a/src/if-options.c
> +++ b/src/if-options.c
> @@ -720,7 +720,7 @@ parse_option(struct dhcpcd_ctx *ctx, const char *ifname, struct if_options *ifo,
>  			break;
>  		}
>  		dl = (size_t)s;
> -		if (s == -1 || (ifo->script = malloc(dl)) == NULL) {
> +		if (s == -1 || (ifo->script = malloc(dl + 1)) == NULL) {
>  			ifo->script = NULL;
>  			logerr(__func__);
>  			return -1;
> -- 


And, if it isn't that simple, at least this works for me.  This is the
valgrind warning that pointed me to it:

> ==8231== Invalid write of size 1
> ==8231==    at 0x40D674: parse_str (if-options.c:397)
> ==8231==    by 0x40E03E: parse_option (if-options.c:728)
> ==8231==    by 0x412F0A: parse_config_line (if-options.c:2205)
> ==8231==    by 0x413C97: read_config (if-options.c:2559)
> ==8231==    by 0x40823F: main (dhcpcd.c:1722)
> ==8231==  Address 0x5237758 is 0 bytes after a block of size 24 alloc'd
> ==8231==    at 0x4C2DF06: malloc (vg_replace_malloc.c:309)
> ==8231==    by 0x40DFC6: parse_option (if-options.c:723)
> ==8231==    by 0x412F0A: parse_config_line (if-options.c:2205)
> ==8231==    by 0x413C97: read_config (if-options.c:2559)
> ==8231==    by 0x40823F: main (dhcpcd.c:1722)

This is dhcpcd 8.1.3 on Linux.  Versions back to 7.2.0 have the same
problem.


          Graham

-- 
------------------------------

*Graham Breed*
Systems Developer, ApplianSys

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