From 0dd6065520742f62678db9dd6728f22b2abd68e2 Mon Sep 17 00:00:00 2001 From: Ruiyu Ni Date: Thu, 13 Sep 2018 16:06:52 +0800 Subject: [PATCH] MdeModulePkg/AbsPointer: Don't access key codes when length is wrong Per USB HID spec, the buffer holding key codes should at least 3-byte long. Today's code assumes that the key codes buffer length is longer than 3-byte and unconditionally accesses the key codes buffer. It's incorrect. The patch fixes the issue by returning Device Error when the length is less than 3-byte. Contributed-under: TianoCore Contribution Agreement 1.1 Signed-off-by: Ruiyu Ni Cc: Star Zeng Cc: Jiewen Yao Cc: Steven Shi Reviewed-by: Star Zeng --- .../UsbMouseAbsolutePointerDxe/UsbMouseAbsolutePointer.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/MdeModulePkg/Bus/Usb/UsbMouseAbsolutePointerDxe/UsbMouseAbsolutePointer.c b/MdeModulePkg/Bus/Usb/UsbMouseAbsolutePointerDxe/UsbMouseAbsolutePointer.c index 965195ca34..42b9147ad8 100644 --- a/MdeModulePkg/Bus/Usb/UsbMouseAbsolutePointerDxe/UsbMouseAbsolutePointer.c +++ b/MdeModulePkg/Bus/Usb/UsbMouseAbsolutePointerDxe/UsbMouseAbsolutePointer.c @@ -813,8 +813,6 @@ OnMouseInterruptComplete ( return EFI_SUCCESS; } - UsbMouseAbsolutePointerDevice->StateChanged = TRUE; - // // Check mouse Data // USB HID Specification specifies following data format: @@ -827,6 +825,12 @@ OnMouseInterruptComplete ( // 2 0 to 7 Y displacement // 3 to n 0 to 7 Device specific (optional) // + if (DataLength < 3) { + return EFI_DEVICE_ERROR; + } + + UsbMouseAbsolutePointerDevice->StateChanged = TRUE; + UsbMouseAbsolutePointerDevice->State.ActiveButtons = *(UINT8 *) Data & (BIT0 | BIT1 | BIT2); UsbMouseAbsolutePointerDevice->State.CurrentX = -- 2.39.2