Re: [PATCH v2 10/16] perf python: Validate attribute setters in pyrf_evsel

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:

Pre-existing issues:
- [Medium] Missing NULL check for attribute deletion in `pyrf_counts_values_set_values` causes a segmentation fault.
--

commit 921733bf92d5e6634715543526c3d25b8346f3c3
Author: Ian Rogers <irogers@google.com>

perf python: Validate attribute setters in pyrf_evsel

This commit adds NULL checks to attribute setters in pyrf_evsel to
ensure an error is correctly reported instead of setting a garbage
value when attempting to delete an attribute.

> diff --git a/tools/perf/util/python.c b/tools/perf/util/python.c
> index 4bf37e2afb18d..657b054f5e515 100644
> --- a/tools/perf/util/python.c
> +++ b/tools/perf/util/python.c
[ ... ]
> @@ -2296,6 +2296,11 @@ static int pyrf_evsel__set_tracking(PyObject *self, PyObject *val, void *closure
>  
>  	CHECK_INITIALIZED_INT(pevsel->evsel, "evsel");
>  
> +	if (val == NULL) {
> +		PyErr_SetString(PyExc_TypeError, "cannot delete attribute");
> +		return -1;
> +	}
> +
>  	is_true = PyObject_IsTrue(val);
>  	if (is_true < 0)
>  		return -1;

[Severity: Medium]
This is a pre-existing issue, but since you are fixing these attribute
deletion issues in pyrf_evsel, should we also fix
pyrf_counts_values_set_values in the same file?

Looking at pyrf_counts_values_set_values, the list parameter is passed
directly to PyList_Check without verifying if it is NULL:

static int pyrf_counts_values_set_values(struct pyrf_counts_values *self,
					 PyObject *list, void *closure)
{
	Py_ssize_t size;
	PyObject *item = NULL;

	if (!PyList_Check(list)) {
		PyErr_SetString(PyExc_TypeError, "Value assigned must be a list");
		return -1;
	}

Could deleting the counts_values.values attribute from a Python script
trigger a segmentation fault here?

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260624051535.3584977-1-irogers@google.com?part=10