linux-kernel - [PATCH 2/2] perf report: Don't add to histogram when there is no thread found

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20230626161059.324046-3-james.clark@arm.com>
Date:   Mon, 26 Jun 2023 17:10:58 +0100
From:   James Clark <james.clark@....com>
To:     linux-perf-users@...r.kernel.org
Cc:     James Clark <james.clark@....com>,
        Peter Zijlstra <peterz@...radead.org>,
        Ingo Molnar <mingo@...hat.com>,
        Arnaldo Carvalho de Melo <acme@...nel.org>,
        Mark Rutland <mark.rutland@....com>,
        Alexander Shishkin <alexander.shishkin@...ux.intel.com>,
        Jiri Olsa <jolsa@...nel.org>,
        Namhyung Kim <namhyung@...nel.org>,
        Ian Rogers <irogers@...gle.com>,
        Adrian Hunter <adrian.hunter@...el.com>,
        Suzuki K Poulose <suzuki.poulose@....com>,
        Mike Leach <mike.leach@...aro.org>,
        Leo Yan <leo.yan@...aro.org>,
        John Garry <john.g.garry@...cle.com>,
        Will Deacon <will@...nel.org>, linux-kernel@...r.kernel.org,
        coresight@...ts.linaro.org, linux-arm-kernel@...ts.infradead.org
Subject: [PATCH 2/2] perf report: Don't add to histogram when there is no thread found

thread__find_map() chooses to exit without assigning a thread to the
addr_location in some scenarios, for example when there are samples from
a guest and perf_guest == false. This results in a segfault when adding
to the histogram because it uses unguarded accesses to the thread member
of the addr_location.

Fix it by exiting early if no thread is set. This fixes the referenced
commit when using perf report with Coresight but probably isn't
exclusive to that case.

Fixes: 8d3031d39fe8 ("perf cs-etm: Track exception level")
Signed-off-by: James Clark <james.clark@....com>
---
 tools/perf/builtin-report.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/tools/perf/builtin-report.c b/tools/perf/builtin-report.c
index dcedfe00f04d..1a2caa4ce5c3 100644
--- a/tools/perf/builtin-report.c
+++ b/tools/perf/builtin-report.c
@@ -293,6 +293,9 @@ static int process_sample_event(struct perf_tool *tool,
 		goto out_put;
 	}
 
+	if (!al.thread)
+		goto out_put;
+
 	if (rep->stitch_lbr)
 		thread__set_lbr_stitch_enable(al.thread, true);
 
-- 
2.34.1