trace_event__cleanup() frees t->pevent but never clears the
pointer. It can be called twice on the same trace_event: once
from trace_report()'s error path, and again from
perf_session__delete() during session teardown, resulting in a
double free / use-after-free.

Separately, trace_event__init() overwrites t->pevent/t->plugin_list
without releasing any existing handle, leaking memory if it's
called more than once on the same struct. eg. via a perf.data
file with multiple PERF_RECORD_HEADER_TRACING_DATA headers.

Guard against re-entry by returning early if t->pevent is already
NULL, and clear it after cleanup so a repeat call is a safe no-op.
Call trace_event__cleanup() at the start of trace_event__init(),
so a repeated init releases any existing handle before allocating
a new one.

Signed-off-by: Tanushree Shah <[email protected]>
---
 tools/perf/util/trace-event.c | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/tools/perf/util/trace-event.c b/tools/perf/util/trace-event.c
index 6a8c66c64b70..000c1e1d68c1 100644
--- a/tools/perf/util/trace-event.c
+++ b/tools/perf/util/trace-event.c
@@ -26,7 +26,11 @@ static bool tevent_initialized;
 
 int trace_event__init(struct trace_event *t)
 {
-       struct tep_handle *pevent = tep_alloc();
+       struct tep_handle *pevent;
+
+       trace_event__cleanup(t);
+
+       pevent = tep_alloc();
 
        if (pevent) {
                t->plugin_list = tep_load_plugins(pevent);
@@ -63,8 +67,13 @@ int trace_event__register_resolver(struct machine *machine,
 
 void trace_event__cleanup(struct trace_event *t)
 {
+       if (!t->pevent)
+               return;
+
        tep_unload_plugins(t->plugin_list, t->pevent);
        tep_free(t->pevent);
+       t->pevent = NULL;
+       t->plugin_list = NULL;
 }
 
 /*
-- 
2.47.3


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