[PATCH 5.10 170/227] perf python: Decrement the refcount of just created event on failure

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

5.10-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Arnaldo Carvalho de Melo <acme@redhat.com>

[ Upstream commit 3de5a2bf5b4847f7a59a184568f969f8fe05d57f ]

To avoid a leak if we have the python object but then something happens
and we need to return the operation, decrement the offset of the newly
created object.

Fixes: 377f698db12150a1 ("perf python: Add struct evsel into struct pyrf_event")
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Reviewed-by: Ian Rogers <irogers@google.com>
Link: https://lore.kernel.org/r/20250312203141.285263-5-acme@kernel.org
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 tools/perf/util/python.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/tools/perf/util/python.c b/tools/perf/util/python.c
index 51679d8d40b1b..ab3a444b4b868 100644
--- a/tools/perf/util/python.c
+++ b/tools/perf/util/python.c
@@ -1057,6 +1057,7 @@ static PyObject *pyrf_evlist__read_on_cpu(struct pyrf_evlist *pevlist,
 
 		evsel = perf_evlist__event2evsel(evlist, event);
 		if (!evsel) {
+			Py_DECREF(pyevent);
 			Py_INCREF(Py_None);
 			return Py_None;
 		}
@@ -1068,9 +1069,12 @@ static PyObject *pyrf_evlist__read_on_cpu(struct pyrf_evlist *pevlist,
 		/* Consume the even only after we parsed it out. */
 		perf_mmap__consume(&md->core);
 
-		if (err)
+		if (err) {
+			Py_DECREF(pyevent);
 			return PyErr_Format(PyExc_OSError,
 					    "perf: can't parse sample, err=%d", err);
+		}
+
 		return pyevent;
 	}
 end:
-- 
2.39.5