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From: Namhyung Kim <namhyung@kernel.org>
To: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>,
	Ingo Molnar <mingo@kernel.org>,
	Thomas Gleixner <tglx@linutronix.de>,
	James Clark <james.clark@linaro.org>,
	Jiri Olsa <jolsa@kernel.org>, Ian Rogers <irogers@google.com>,
	Clark Williams <williams@redhat.com>,
	linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org,
	Arnaldo Carvalho de Melo <acme@redhat.com>,
	sashiko-bot <sashiko-bot@kernel.org>, Leo Yan <leo.yan@arm.com>
Subject: Re: [PATCH 5/5] perf arm-spe: Reject zero nr_cpu in metadata to prevent division by zero
Date: Mon, 3 Aug 2026 12:41:12 -0700	[thread overview]
Message-ID: <anDu2L-yfpUFES-h@google.com> (raw)
In-Reply-To: <anDlvtOEBK4QRS9P@x1>

On Mon, Aug 03, 2026 at 04:02:22PM -0300, Arnaldo Carvalho de Melo wrote:
> On Mon, Aug 03, 2026 at 09:46:49PM +0300, Adrian Hunter wrote:
> > On 27/07/2026 19:17, Arnaldo Carvalho de Melo wrote:
> > > From: Arnaldo Carvalho de Melo <acme@redhat.com>
> > > 
> > > arm_spe__alloc_metadata() reads nr_cpu from the auxtrace_info priv
> > > array without validation.  When a crafted perf.data provides nr_cpu=0,
> > > the per_cpu_sz calculation divides by zero:
> > > 
> > >   per_cpu_sz = (metadata_size - (hdr_sz * sizeof(u64))) / (*nr_cpu);
> > > 
> > > Reject nr_cpu <= 0 early, before the division.  The caller already
> > > treats NULL return with metadata_ver != 1 as a parse failure.
> > > 
> > > Fixes: e52abceb4b6c2723 ("perf arm-spe: Dump metadata with version 2")
> > 
> > git blame shows 7842a4b6ff698 "perf arm-spe: Support metadata version 2"
> > for the relevant lines
> 
> That is right, Namhyung, can you please fix this Fixme tag while merging?

Sure, will do!

Thanks,
Namhyung


  reply	other threads:[~2026-08-03 19:41 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-07-27 16:17 [PATCHES 0/5 v1] perf tools auxtrace hardening series Arnaldo Carvalho de Melo
2026-07-27 16:17 ` [PATCH 1/5] perf thread-stack: Fix heap buffer overflow on branch stack wrap copy Arnaldo Carvalho de Melo
2026-07-27 16:17 ` [PATCH 2/5] perf auxtrace: Fix queue grow overflow and old array leak Arnaldo Carvalho de Melo
2026-07-27 16:17 ` [PATCH 3/5] perf intel-pt: Fix off-by-one in auxtrace_info minimum size check Arnaldo Carvalho de Melo
2026-07-27 16:17 ` [PATCH 4/5] perf intel-bts: " Arnaldo Carvalho de Melo
2026-07-27 16:17 ` [PATCH 5/5] perf arm-spe: Reject zero nr_cpu in metadata to prevent division by zero Arnaldo Carvalho de Melo
2026-08-03 18:46   ` Adrian Hunter
2026-08-03 19:02     ` Arnaldo Carvalho de Melo
2026-08-03 19:41       ` Namhyung Kim [this message]
2026-07-27 16:31 ` [PATCHES 0/5 v1] perf tools auxtrace hardening series James Clark
2026-07-31 23:27 ` Namhyung Kim
2026-08-03 18:46   ` Adrian Hunter
2026-08-03 19:02     ` Arnaldo Carvalho de Melo
2026-08-04 17:04 ` Namhyung Kim

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