[PATCH 3/4] HID: multitouch: use __free(kfree) to clean up temporary buffers

Benjamin Tissoires
2026-04-15T09:38:59Z

This simplifies error handling and protects against memory leaks.

Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>
---
drivers/hid/hid-multitouch.c | 16 ++++++----------
1 file changed, 6 insertions(+), 10 deletions(-)

diff --git a/drivers/hid/hid-multitouch.c b/drivers/hid/hid-multitouch.c
index eeab0b6e32cc..b19463e545d6 100644
--- a/drivers/hid/hid-multitouch.c
+++ b/drivers/hid/hid-multitouch.c
@@ -507,7 +507,6 @@ static void mt_get_feature(struct hid_device *hdev, struct hid_report *report)
{
int ret;
u32 size = hid_report_len(report);
- u8 *buf;

/*
* Do not fetch the feature report if the device has been explicitly
@@ -516,7 +515,7 @@ static void mt_get_feature(struct hid_device *hdev, struct hid_report *report)
if (hdev->quirks & HID_QUIRK_NO_INIT_REPORTS)
return;

- buf = hid_alloc_report_buf(report, GFP_KERNEL);
+ u8 *buf __free(kfree) = hid_alloc_report_buf(report, GFP_KERNEL);
if (!buf)
return;

@@ -529,7 +528,7 @@ static void mt_get_feature(struct hid_device *hdev, struct hid_report *report)
/* The report ID in the request and the response should match */
if (report->id != buf[0]) {
hid_err(hdev, "Returned feature report did not match the request\n");
- goto free;
+ return;
}

ret = hid_report_raw_event(hdev, HID_FEATURE_REPORT, buf,
@@ -537,9 +536,6 @@ static void mt_get_feature(struct hid_device *hdev, struct hid_report *report)
if (ret)
dev_warn(&hdev->dev, "failed to report feature\n");
}
-
-free:
- kfree(buf);
}

static void mt_feature_mapping(struct hid_device *hdev,
@@ -1658,7 +1654,6 @@ static bool mt_need_to_apply_feature(struct hid_device *hdev,
struct mt_class *cls = &td->mtclass;
struct hid_report *report = field->report;
unsigned int index = usage->usage_index;
- char *buf;
u32 report_len;
int max;

@@ -1673,17 +1668,18 @@ static bool mt_need_to_apply_feature(struct hid_device *hdev,
return false;

if (cls->quirks & MT_QUIRK_FORCE_GET_FEATURE) {
- report_len = hid_report_len(report);
- buf = hid_alloc_report_buf(report, GFP_KERNEL);
+ char *buf __free(kfree) = hid_alloc_report_buf(report, GFP_KERNEL);
+
if (!buf) {
hid_err(hdev,
"failed to allocate buffer for report\n");
return false;
}
+
+ report_len = hid_report_len(report);
hid_hw_raw_request(hdev, report->id, buf, report_len,
HID_FEATURE_REPORT,
HID_REQ_GET_REPORT);
- kfree(buf);
}

field->value[index] = td->inputmode_value;

--
2.53.0