Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Date:   Tue, 2 Oct 2018 12:48:52 -0300
From:   Arnaldo Carvalho de Melo <acme@redhat.com>
To:     Sanskriti Sharma <sansharm@redhat.com>
Cc:     linux-kernel@vger.kernel.org, Jiri Olsa <jolsa@redhat.com>,
        Joe Lawrence <joe.lawrence@redhat.com>
Subject: Re: [PATCH 4/5] perf tools: avoid double free in read_event_file()
Message-ID: <20181002154852.GE9457@redhat.com>
References: <1538490554-8161-1-git-send-email-sansharm@redhat.com>
 <1538490554-8161-5-git-send-email-sansharm@redhat.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <1538490554-8161-5-git-send-email-sansharm@redhat.com>
User-Agent: Mutt/1.5.20 (2009-12-10)
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

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