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From:   Shang XiaoJing <shangxiaojing@huawei.com>
To:     <rostedt@goodmis.org>, <acme@redhat.com>,
        <linux-kernel@vger.kernel.org>
CC:     <namhyung@kernel.org>, <shangxiaojing@huawei.com>
Subject: [PATCH] tools lib traceevent: Fix double free in event_read_fields()
Date:   Mon, 17 Oct 2022 16:59:37 +0800
Message-ID: <20221017085937.8583-1-shangxiaojing@huawei.com>
MIME-Version: 1.0
Content-Type: text/plain
Precedence: bulk

There is a double free in event_read_fields(). After calling free_token()
to free the token, if append() failed, then goto fail, which will call
free_token() again. Triggered by compiling with perf and run "perf sched
record". Fix the double free by goto fail_expect instead of fail while
append() failed, which won't call redundant free_token().

BUG: double free
free(): double free detected in tcache 2
Aborted

Fixes: d286447f23cd ("tools lib traceevent: Handle realloc() failure path")
Signed-off-by: Shang XiaoJing <shangxiaojing@huawei.com>
---
 tools/lib/traceevent/event-parse.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/lib/traceevent/event-parse.c b/tools/lib/traceevent/event-parse.c
index 8e24c4c78c7f..e0a5a22fe702 100644
--- a/tools/lib/traceevent/event-parse.c
+++ b/tools/lib/traceevent/event-parse.c
@@ -1594,7 +1594,7 @@ static int event_read_fields(struct tep_event *event, struct tep_format_field **
 			ret = append(&brackets, "", "]");
 			if (ret < 0) {
 				free(brackets);
-				goto fail;
+				goto fail_expect;
 			}
 
 			/* add brackets to type */
-- 
2.17.1