Re: [PATCH] perf annotate: fix heap overflow

From: Jiri Olsa <jolsa@redhat.com>
To: Ian Rogers <irogers@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>,
	Ingo Molnar <mingo@redhat.com>,
	Arnaldo Carvalho de Melo <acme@kernel.org>,
	Mark Rutland <mark.rutland@arm.com>,
	Alexander Shishkin <alexander.shishkin@linux.intel.com>,
	Namhyung Kim <namhyung@kernel.org>,
	Jin Yao <yao.jin@linux.intel.com>,
	Song Liu <songliubraving@fb.com>,
	linux-kernel@vger.kernel.org,
	Stephane Eranian <eranian@google.com>
Subject: Re: [PATCH] perf annotate: fix heap overflow
Date: Mon, 28 Oct 2019 20:29:08 +0100	[thread overview]
Message-ID: <20191028192908.GA28772@krava> (raw)
In-Reply-To: <20191026035644.217548-1-irogers@google.com>

On Fri, Oct 25, 2019 at 08:56:44PM -0700, Ian Rogers wrote:
> Fix expand_tabs that copies the source lines '\0' and then appends
> another '\0' at a potentially out of bounds address.

not sure it could get out of bounds, but i think
the change is right, it matches the memcpy before
and I dont see reason to add +1

Acked-by: Jiri Olsa <jolsa@kernel.org>

thanks,
jirka


> 
> Signed-off-by: Ian Rogers <irogers@google.com>
> ---
>  tools/perf/util/annotate.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/tools/perf/util/annotate.c b/tools/perf/util/annotate.c
> index ef1866a902c4..bee0fee122f8 100644
> --- a/tools/perf/util/annotate.c
> +++ b/tools/perf/util/annotate.c
> @@ -1892,7 +1892,7 @@ static char *expand_tabs(char *line, char **storage, size_t *storage_len)
>  	}
>  
>  	/* Expand the last region. */
> -	len = line_len + 1 - src;
> +	len = line_len - src;
>  	memcpy(&new_line[dst], &line[src], len);
>  	dst += len;
>  	new_line[dst] = '\0';
> -- 
> 2.24.0.rc0.303.g954a862665-goog
>