linux-kernel - [PATCH V2 1/3] perf parse-events: Fix segfault when event parser gets an error

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: <20220809080702.6921-2-adrian.hunter@intel.com>
Date:   Tue,  9 Aug 2022 11:07:00 +0300
From:   Adrian Hunter <adrian.hunter@...el.com>
To:     Arnaldo Carvalho de Melo <acme@...nel.org>
Cc:     Jiri Olsa <jolsa@...hat.com>, Namhyung Kim <namhyung@...nel.org>,
        Ian Rogers <irogers@...gle.com>, linux-kernel@...r.kernel.org
Subject: [PATCH V2 1/3] perf parse-events: Fix segfault when event parser gets an error

parse_events() is often called with parse_events_error set to NULL.
Make parse_events_error__handle() not segfault in that case.

A subsequent patch changes to avoid passing NULL in the first place.

Fixes: 43eb05d06679 ("perf tests: Support 'Track with sched_switch' test for hybrid")
Signed-off-by: Adrian Hunter <adrian.hunter@...el.com>
---
 tools/perf/util/parse-events.c | 14 +++++++++++---
 1 file changed, 11 insertions(+), 3 deletions(-)

diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
index 206c76623c06..dfc7d7a0ec4e 100644
--- a/tools/perf/util/parse-events.c
+++ b/tools/perf/util/parse-events.c
@@ -2256,9 +2256,12 @@ void parse_events_error__exit(struct parse_events_error *err)
 void parse_events_error__handle(struct parse_events_error *err, int idx,
 				char *str, char *help)
 {
-	if (WARN(!str, "WARNING: failed to provide error string\n")) {
-		free(help);
-		return;
+	if (WARN(!str, "WARNING: failed to provide error string\n"))
+		goto out_free;
+	if (!err) {
+		/* Assume caller does not want message printed */
+		pr_debug("event syntax error: %s\n", str);
+		goto out_free;
 	}
 	switch (err->num_errors) {
 	case 0:
@@ -2284,6 +2287,11 @@ void parse_events_error__handle(struct parse_events_error *err, int idx,
 		break;
 	}
 	err->num_errors++;
+	return;
+
+out_free:
+	free(str);
+	free(help);
 }
 
 #define MAX_WIDTH 1000
-- 
2.25.1