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From: Ian Rogers <irogers@google.com>
To: 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>,
	Jiri Olsa <jolsa@redhat.com>, Namhyung Kim <namhyung@kernel.org>,
	Leo Yan <leo.yan@linaro.org>,
	Andre Przywara <andre.przywara@arm.com>,
	Will Deacon <will@kernel.org>, Dave Martin <Dave.Martin@arm.com>,
	linux-kernel@vger.kernel.org
Cc: Stephane Eranian <eranian@google.com>, Ian Rogers <irogers@google.com>
Subject: [PATCH] perf arm-spe: Avoid potential buffer overrun.
Date: Wed,  7 Apr 2021 08:39:55 -0700	[thread overview]
Message-ID: <20210407153955.317215-1-irogers@google.com> (raw)

SPE extended headers are >1 byte so ensure the buffer contains at
least this before reading. This issue was detected by fuzzing.

Signed-off-by: Ian Rogers <irogers@google.com>
---
 tools/perf/util/arm-spe-decoder/arm-spe-pkt-decoder.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/tools/perf/util/arm-spe-decoder/arm-spe-pkt-decoder.c b/tools/perf/util/arm-spe-decoder/arm-spe-pkt-decoder.c
index f3ac9d40cebf..2e5eff4f8f03 100644
--- a/tools/perf/util/arm-spe-decoder/arm-spe-pkt-decoder.c
+++ b/tools/perf/util/arm-spe-decoder/arm-spe-pkt-decoder.c
@@ -210,8 +210,10 @@ static int arm_spe_do_get_packet(const unsigned char *buf, size_t len,
 
 	if ((hdr & SPE_HEADER0_MASK2) == SPE_HEADER0_EXTENDED) {
 		/* 16-bit extended format header */
-		ext_hdr = 1;
+		if (len == 1)
+			return ARM_SPE_BAD_PACKET;
 
+		ext_hdr = 1;
 		hdr = buf[1];
 		if (hdr == SPE_HEADER1_ALIGNMENT)
 			return arm_spe_get_alignment(buf, len, packet);
-- 
2.31.0.208.g409f899ff0-goog


             reply	other threads:[~2021-04-07 15:40 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-04-07 15:39 Ian Rogers [this message]
2021-04-07 19:24 ` [PATCH] perf arm-spe: Avoid potential buffer overrun Arnaldo Carvalho de Melo

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