From 657cd3a42e937276262c0a8ae6b01a87004309de Mon Sep 17 00:00:00 2001 From: Jameson Thies Date: Wed, 22 Jul 2026 19:50:59 +0000 Subject: [PATCH] power: supply: cros_usbpd: Limit port counts to EC_USB_PD_MAX_PORTS Currently the cros_usbpd-charger driver probe iterates based on raw charger port count returned by the embedded controller. The only check is against the number of USB PD ports which the embedded controller also defines. A malicious embedded controller could return an inaccurate port count (up to 255) resulting in an out of bounds write and subsequent memory corruption. Update helper functions in cros_usbpd-charger to limit port counts to EC_USB_PD_MAX_PORTS. Fixes: 3af15cfacd1e ("power: supply: cros: add support for dedicated port") Cc: stable@vger.kernel.org Signed-off-by: Jameson Thies Reviewed-by: Benson Leung Link: https://patch.msgid.link/20260722195059.1420738-1-jthies@google.com Signed-off-by: Sebastian Reichel --- drivers/power/supply/cros_usbpd-charger.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/drivers/power/supply/cros_usbpd-charger.c b/drivers/power/supply/cros_usbpd-charger.c index e410048aa0ab..9a1038981824 100644 --- a/drivers/power/supply/cros_usbpd-charger.c +++ b/drivers/power/supply/cros_usbpd-charger.c @@ -125,6 +125,11 @@ static int cros_usbpd_charger_get_num_ports(struct charger_data *charger) if (ret < 0) return ret; + if (resp.port_count > EC_USB_PD_MAX_PORTS) { + dev_warn(charger->dev, "Charge port count out of bounds\n"); + return EC_USB_PD_MAX_PORTS; + } + return resp.port_count; } @@ -138,6 +143,11 @@ static int cros_usbpd_charger_get_usbpd_num_ports(struct charger_data *charger) if (ret < 0) return ret; + if (resp.num_ports > EC_USB_PD_MAX_PORTS) { + dev_warn(charger->dev, "USB PD port count out of bounds\n"); + return EC_USB_PD_MAX_PORTS; + } + return resp.num_ports; }