From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received-SPF: Pass (sender SPF authorized) identity=mailfrom; client-ip=192.55.52.88; helo=mga01.intel.com; envelope-from=star.zeng@intel.com; receiver=edk2-devel@lists.01.org Received: from mga01.intel.com (mga01.intel.com [192.55.52.88]) (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 7DAC42117923F for ; Mon, 15 Oct 2018 22:03:55 -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 fmsmga101.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 15 Oct 2018 22:03:55 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.54,387,1534834800"; d="scan'208";a="100573790" Received: from shzintpr02.sh.intel.com (HELO [10.7.209.21]) ([10.239.4.160]) by orsmga002.jf.intel.com with ESMTP; 15 Oct 2018 22:03:53 -0700 To: Ruiyu Ni , edk2-devel@lists.01.org Cc: Jiewen Yao , star.zeng@intel.com References: <20181015063833.61304-1-ruiyu.ni@intel.com> <20181015063833.61304-10-ruiyu.ni@intel.com> From: "Zeng, Star" Message-ID: <97c2e922-6bb5-413f-accd-c84ce9857a08@intel.com> Date: Tue, 16 Oct 2018 13:03:23 +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: <20181015063833.61304-10-ruiyu.ni@intel.com> Subject: Re: [PATCH 09/11] MdeModulePkg/UsbMouse: 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 05:03:55 -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 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 > --- > MdeModulePkg/Bus/Usb/UsbMouseDxe/UsbMouse.c | 8 ++++++-- > 1 file changed, 6 insertions(+), 2 deletions(-) > > diff --git a/MdeModulePkg/Bus/Usb/UsbMouseDxe/UsbMouse.c b/MdeModulePkg/Bus/Usb/UsbMouseDxe/UsbMouse.c > index 9324994975..d4bcf15929 100644 > --- a/MdeModulePkg/Bus/Usb/UsbMouseDxe/UsbMouse.c > +++ b/MdeModulePkg/Bus/Usb/UsbMouseDxe/UsbMouse.c > @@ -811,8 +811,6 @@ OnMouseInterruptComplete ( > return EFI_SUCCESS; > } > > - UsbMouseDevice->StateChanged = TRUE; > - > // > // Check mouse Data > // USB HID Specification specifies following data format: > @@ -825,6 +823,12 @@ OnMouseInterruptComplete ( > // 2 0 to 7 Y displacement > // 3 to n 0 to 7 Device specific (optional) > // > + if ((Data != NULL) && (DataLength < 3)) { > + return EFI_DEVICE_ERROR; > + } Ray, Thanks for the patch. Data is impossible to be NULL here as 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; } Thanks, Star > + > + UsbMouseDevice->StateChanged = TRUE; > + > UsbMouseDevice->State.LeftButton = (BOOLEAN) ((*(UINT8 *) Data & BIT0) != 0); > UsbMouseDevice->State.RightButton = (BOOLEAN) ((*(UINT8 *) Data & BIT1) != 0); > UsbMouseDevice->State.RelativeMovementX += *((INT8 *) Data + 1); >