From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received-SPF: Pass (sender SPF authorized) identity=mailfrom; client-ip=134.134.136.65; helo=mga03.intel.com; envelope-from=star.zeng@intel.com; receiver=edk2-devel@lists.01.org Received: from mga03.intel.com (mga03.intel.com [134.134.136.65]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ml01.01.org (Postfix) with ESMTPS id 7253621179256 for ; Mon, 15 Oct 2018 21:53:16 -0700 (PDT) X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga002.jf.intel.com ([10.7.209.21]) by orsmga103.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 15 Oct 2018 21:53:15 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.54,387,1534834800"; d="scan'208";a="100571732" Received: from shzintpr01.sh.intel.com (HELO [10.7.209.21]) ([10.239.4.80]) by orsmga002.jf.intel.com with ESMTP; 15 Oct 2018 21:53:14 -0700 To: Ruiyu Ni , edk2-devel@lists.01.org Cc: Jiewen Yao , star.zeng@intel.com References: <20181015063833.61304-1-ruiyu.ni@intel.com> <20181015063833.61304-8-ruiyu.ni@intel.com> From: "Zeng, Star" Message-ID: Date: Tue, 16 Oct 2018 12:52:44 +0800 User-Agent: Mozilla/5.0 (Windows NT 6.3; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 MIME-Version: 1.0 In-Reply-To: <20181015063833.61304-8-ruiyu.ni@intel.com> Subject: Re: [PATCH 07/11] MdeModulePkg/UsbKb: Don't access key codes when length is wrong X-BeenThere: edk2-devel@lists.01.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: EDK II Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 16 Oct 2018 04:53:16 -0000 Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit On 2018/10/15 14:38, Ruiyu Ni wrote: > Per USB HID spec, the buffer holding key codes should be 8-byte > long. > Today's code assumes that the key codes buffer length is 8-byte > long 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 8-byte. > > Contributed-under: TianoCore Contribution Agreement 1.1 > Signed-off-by: Ruiyu Ni > Cc: Star Zeng > Cc: Jiewen Yao > Cc: Steven Shi > --- > MdeModulePkg/Bus/Usb/UsbKbDxe/KeyBoard.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/MdeModulePkg/Bus/Usb/UsbKbDxe/KeyBoard.c b/MdeModulePkg/Bus/Usb/UsbKbDxe/KeyBoard.c > index 9cb4b5db6b..384d7e2f07 100644 > --- a/MdeModulePkg/Bus/Usb/UsbKbDxe/KeyBoard.c > +++ b/MdeModulePkg/Bus/Usb/UsbKbDxe/KeyBoard.c > @@ -1059,6 +1059,10 @@ KeyboardHandler ( > // Byte 1 is reserved. > // Bytes 2 to 7 are keycodes. > // > + if ((Data != NULL) && (DataLength < 8)) { > + return EFI_DEVICE_ERROR; > + } Ray, Thanks for the patch. The NULL check to Data has been done by code piece // // If no error and no data, just return EFI_SUCCESS. // if (DataLength == 0 || Data == NULL) { return EFI_SUCCESS; } And do you think whether the code can use DataLength != 8 instead of DataLength < 8? Thanks, Star > + > CurKeyCodeBuffer = (UINT8 *) Data; > OldKeyCodeBuffer = UsbKeyboardDevice->LastKeyCodeArray; > >