From cac61b58a3b6340c52afa06bb15eac033158db2f Mon Sep 17 00:00:00 2001 From: "T.J. Mercier" Date: Fri, 17 Apr 2026 08:47:02 -0700 Subject: [PATCH] HID: playstation: Clamp num_touch_reports A device would never lie about the number of touch reports would it? If it does the loop in dualshock4_parse_report will read off the end of the touch_reports array, up to about 2 KiB for the maximum number of 256 loop iteraions. The data that is read is emitted via evdev if the DS4_TOUCH_POINT_INACTIVE bit happens to be set. Protect against this by clamping the num_touch_reports value provided by the device to the maximum size of the touch_reports array. Fixes: 752038248808 ("HID: playstation: add DualShock4 touchpad support.") Cc: stable@vger.kernel.org Reported-by: Xingyu Jin Signed-off-by: T.J. Mercier Signed-off-by: Jiri Kosina --- drivers/hid/hid-playstation.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/hid/hid-playstation.c b/drivers/hid/hid-playstation.c index c43caac20b61b..e485373316756 100644 --- a/drivers/hid/hid-playstation.c +++ b/drivers/hid/hid-playstation.c @@ -2384,7 +2384,8 @@ static int dualshock4_parse_report(struct ps_device *ps_dev, struct hid_report * } ds4_report = &usb->common; - num_touch_reports = usb->num_touch_reports; + num_touch_reports = min_t(u8, usb->num_touch_reports, + ARRAY_SIZE(usb->touch_reports)); touch_reports = usb->touch_reports; } else if (hdev->bus == BUS_BLUETOOTH && report->id == DS4_INPUT_REPORT_BT && size == DS4_INPUT_REPORT_BT_SIZE) { @@ -2404,7 +2405,8 @@ static int dualshock4_parse_report(struct ps_device *ps_dev, struct hid_report * } ds4_report = &bt->common; - num_touch_reports = bt->num_touch_reports; + num_touch_reports = min_t(u8, bt->num_touch_reports, + ARRAY_SIZE(bt->touch_reports)); touch_reports = bt->touch_reports; } else if (hdev->bus == BUS_BLUETOOTH && report->id == DS4_INPUT_REPORT_BT_MINIMAL && -- 2.47.3