[PATCH] tools lib traceevent: Fix double free in event_read_fields()

[Shang XiaoJing]

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@xxxxxxxxxx>
---
 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