Re: [PATCH 4/5] perf tools: avoid double free in read_event_file()

[Arnaldo Carvalho de Melo <acme@redhat.com>]

Em Tue, Oct 02, 2018 at 10:29:13AM -0400, Sanskriti Sharma escreveu:
> The temporary 'buf' buffer allocated in read_event_file() may be freed
> twice.  Move the free() call to the common function exit point.
> 
> Fixes the following coverity complaints:
> 
>   Error: USE_AFTER_FREE (CWE-825):
>   tools/perf/util/trace-event-read.c:309: double_free: Calling "free"
>   frees pointer "buf" which has already been freed.

Thanks, applied.

- Arnaldo
 
> Signed-off-by: Sanskriti Sharma <sansharm@redhat.com>
> ---
>  tools/perf/util/trace-event-read.c | 4 +---
>  1 file changed, 1 insertion(+), 3 deletions(-)
> 
> diff --git a/tools/perf/util/trace-event-read.c b/tools/perf/util/trace-event-read.c
> index 3dfc1db..6a0d0f2 100644
> --- a/tools/perf/util/trace-event-read.c
> +++ b/tools/perf/util/trace-event-read.c
> @@ -297,10 +297,8 @@ static int read_event_file(struct tep_handle *pevent, char *sys,
>  	}
>  
>  	ret = do_read(buf, size);
> -	if (ret < 0) {
> -		free(buf);
> +	if (ret < 0)
>  		goto out;
> -	}
>  
>  	ret = parse_event_file(pevent, buf, size, sys);
>  	if (ret < 0)
> -- 
> 1.8.3.1