From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Douthit Subject: [PATCH 2/2] i2c: ismt: Return EMSGSIZE for block reads with bogus length Date: Mon, 7 Aug 2017 17:11:00 -0400 Message-ID: <1502140260-13789-3-git-send-email-stephend@adiengineering.com> References: <1502140260-13789-1-git-send-email-stephend@adiengineering.com> Mime-Version: 1.0 Content-Type: text/plain Return-path: Received: from mail-he1eur01on0102.outbound.protection.outlook.com ([104.47.0.102]:13680 "EHLO EUR01-HE1-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751761AbdHGVLi (ORCPT ); Mon, 7 Aug 2017 17:11:38 -0400 In-Reply-To: <1502140260-13789-1-git-send-email-stephend@adiengineering.com> Sender: linux-i2c-owner@vger.kernel.org List-Id: linux-i2c@vger.kernel.org To: seth.heasley@intel.com, nhorman@tuxdriver.com Cc: wsa@the-dreams.de, danp@adiengineering.com, stephend@adiengineering.com, linux-i2c@vger.kernel.org, linux-kernel@vger.kernel.org Compare the number of bytes actually seen on the wire to the byte count field returned by the slave device. Previously we just overwrote the byte count returned by the slave with the real byte count and let the caller figure out if the message was sane. Signed-off-by: Stephen Douthit Tested-by: Dan Priamo --- drivers/i2c/busses/i2c-ismt.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/i2c/busses/i2c-ismt.c b/drivers/i2c/busses/i2c-ismt.c index 9af2337..22ffcb7 100644 --- a/drivers/i2c/busses/i2c-ismt.c +++ b/drivers/i2c/busses/i2c-ismt.c @@ -341,8 +341,10 @@ static int ismt_process_desc(const struct ismt_desc *desc, break; case I2C_SMBUS_BLOCK_DATA: case I2C_SMBUS_I2C_BLOCK_DATA: + if (desc->rxbytes != dma_buffer[0] + 1) + return -EMSGSIZE; + memcpy(data->block, dma_buffer, desc->rxbytes); - data->block[0] = desc->rxbytes - 1; break; } return 0; -- 2.7.5