Re: [PATCH] fix order of error checking in libsepol

[Stephen Smalley <sds@xxxxxxxxxxxxx>]

On Fri, 2005-08-12 at 14:22 -0500, serue@xxxxxxxxxx wrote:
> The following patch fixes a bug found by Coverity in libsepol:
> 
> 	In write.c, a check for items==0 is done after a goto out: if
> 	items!=1, resulting in dead code, and rc==-1 when items==0
> 	(which I assume is not intended).
> 
> thanks,
> -serge
> 
> Index: src/write.c
> ===================================================================
> --- src.orig/write.c
> +++ src/write.c
> @@ -567,10 +567,9 @@ static int cond_write_av_list(policydb_t
>  	
>  	buf[0] = cpu_to_le32(len);
>  	items = put_entry(buf, sizeof(uint32_t), 1, fp);
> -	if (items != 1)
> -		goto out;
> -	if (items == 0) {
> -		rc = 0;
> +	if (items != 1) {
> +		if (items == 0)
> +			rc = 0;
>  		goto out;
>  	}

Actually, I think what was intended here was:
	if (items != 1)
		goto out;
	if (len == 0) {
		rc = 0;
		goto out;
	}

items is the number of successfully written items, so anything other
than 1 at that point is indeed an error, whereas len may be 0, in which
case we can skip the list loop (not that there is any harm in just
falling through to it).

-- 
Stephen Smalley
National Security Agency


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