From 288a81a8507052bcfbf884d39a463c44c42c5fd9 Mon Sep 17 00:00:00 2001 From: Greg Kroah-Hartman Date: Wed, 13 May 2026 17:52:55 +0200 Subject: [PATCH] usb: typec: ucsi: validate connector number in ucsi_connector_change() The connector number in a UCSI CCI notification is a 7-bit field supplied by the PPM. ucsi_connector_change() uses it to index the ucsi->connector[] array without checking it against the number of connectors the PPM reported at init time, so a buggy or malicious PPM (EC firmware, or an I2C-attached UCSI controller on the ccg / stm32g0 / glink transports) can drive schedule_work() on memory past the end of the array. Reject connector numbers that are zero or exceed cap.num_connectors before dereferencing the array. Assisted-by: gkh_clanker_t1000 Cc: Heikki Krogerus Cc: Benson Leung Cc: Jameson Thies Cc: Nathan Rebello Cc: Johan Hovold Cc: Pooja Katiyar Cc: Hsin-Te Yuan Cc: Abel Vesa Cc: stable Reviewed-by: Abel Vesa Reviewed-by: Heikki Krogerus Reviewed-by: Benson Leung Link: https://patch.msgid.link/2026051351-truck-steadfast-df48@gregkh Signed-off-by: Greg Kroah-Hartman --- drivers/usb/typec/ucsi/ucsi.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/drivers/usb/typec/ucsi/ucsi.c b/drivers/usb/typec/ucsi/ucsi.c index 5b7ad9e99cb9..539dc706798d 100644 --- a/drivers/usb/typec/ucsi/ucsi.c +++ b/drivers/usb/typec/ucsi/ucsi.c @@ -1380,13 +1380,22 @@ static void ucsi_handle_connector_change(struct work_struct *work) */ void ucsi_connector_change(struct ucsi *ucsi, u8 num) { - struct ucsi_connector *con = &ucsi->connector[num - 1]; + struct ucsi_connector *con; if (!(ucsi->ntfy & UCSI_ENABLE_NTFY_CONNECTOR_CHANGE)) { dev_dbg(ucsi->dev, "Early connector change event\n"); return; } + if (!num || num > ucsi->cap.num_connectors) { + dev_warn_ratelimited(ucsi->dev, + "Bogus connector change on %u (max %u)\n", + num, ucsi->cap.num_connectors); + return; + } + + con = &ucsi->connector[num - 1]; + if (!test_and_set_bit(EVENT_PENDING, &ucsi->flags)) schedule_work(&con->work); }