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From: Arnaldo Carvalho de Melo <arnaldo.melo@gmail.com>
To: Vince Weaver <vincent.weaver@maine.edu>
Cc: linux-kernel@vger.kernel.org,
	Peter Zijlstra <peterz@infradead.org>,
	Ingo Molnar <mingo@redhat.com>,
	Alexander Shishkin <alexander.shishkin@linux.intel.com>,
	Jiri Olsa <jolsa@redhat.com>, Namhyung Kim <namhyung@kernel.org>
Subject: Re: [patch] perf tool buffer overflow in perf_header__read_build_ids
Date: Fri, 26 Jul 2019 16:05:41 -0300	[thread overview]
Message-ID: <20190726190541.GC20482@kernel.org> (raw)
In-Reply-To: <alpine.DEB.2.21.1907231639120.14532@macbook-air>

Em Tue, Jul 23, 2019 at 04:42:30PM -0400, Vince Weaver escreveu:
> Hello
> 
> my perf_tool_fuzzer has found another issue, this one a buffer overflow
> in perf_header__read_build_ids.  The build id filename is read in with a 
> filename length read from the perf.data file, but this can be longer than
> PATH_MAX which will smash the stack.
> 
> This might not be the right fix, not sure if filename should be NUL
> terminated or not.
> 
> Signed-off-by: Vince Weaver <vincent.weaver@maine.edu>
> 
> diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c
> index c24db7f4909c..9a893a26e678 100644
> --- a/tools/perf/util/header.c
> +++ b/tools/perf/util/header.c
> @@ -2001,6 +2001,9 @@ static int perf_header__read_build_ids(struct perf_header *header,
>  			perf_event_header__bswap(&bev.header);
>  
>  		len = bev.header.size - sizeof(bev);
> +
> +		if (len>PATH_MAX) len=PATH_MAX;
> +

Humm, I wonder if we shouldn't just declare the whole file invalid like
you did with the previous patch?

- Arnaldo

>  		if (readn(input, filename, len) != len)
>  			goto out;
>  		/*

  reply	other threads:[~2019-07-26 19:05 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-07-23 15:06 [patch] perf tool divide by zero error if f_header.attr_size==0 Vince Weaver
2019-07-23 15:17 ` Arnaldo Carvalho de Melo
2019-07-23 20:42 ` [patch] perf tool buffer overflow in perf_header__read_build_ids Vince Weaver
2019-07-26 19:05   ` Arnaldo Carvalho de Melo [this message]
2019-08-23 20:42     ` Vince Weaver
2019-08-25 14:33       ` Arnaldo Carvalho de Melo
2019-07-26 19:00 ` [patch] perf tool divide by zero error if f_header.attr_size==0 Arnaldo Carvalho de Melo
2019-07-29 21:34 ` [tip:perf/urgent] perf header: Fix " tip-bot for Vince Weaver

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