Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S966424AbcDLSMa (ORCPT ); Tue, 12 Apr 2016 14:12:30 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:49069 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S966270AbcDLSIR (ORCPT ); Tue, 12 Apr 2016 14:08:17 -0400 From: Luis Henriques To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Insu Yun , "Martin K. Petersen" , Ben Hutchings , Luis Henriques Subject: [PATCH 3.16.y-ckt 08/17] ipr: Fix out-of-bounds null overwrite Date: Tue, 12 Apr 2016 19:07:55 +0100 Message-Id: <1460484484-22395-9-git-send-email-luis.henriques@canonical.com> In-Reply-To: <1460484484-22395-1-git-send-email-luis.henriques@canonical.com> References: <1460484484-22395-1-git-send-email-luis.henriques@canonical.com> X-Extended-Stable: 3.16 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1572 Lines: 43 3.16.7-ckt27 -stable review patch. If anyone has any objections, please let me know. ---8<------------------------------------------------------------ From: Insu Yun commit d63c7dd5bcb9441af0526d370c43a65ca2c980d9 upstream. Return value of snprintf is not bound by size value, 2nd argument. (https://www.kernel.org/doc/htmldocs/kernel-api/API-snprintf.html). Return value is number of printed chars, can be larger than 2nd argument. Therefore, it can write null byte out of bounds ofbuffer. Since snprintf puts null, it does not need to put additional null byte. Signed-off-by: Insu Yun Reviewed-by: Shane Seymour Signed-off-by: Martin K. Petersen Cc: Ben Hutchings Signed-off-by: Luis Henriques --- drivers/scsi/ipr.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/drivers/scsi/ipr.c b/drivers/scsi/ipr.c index d2c3fdcf90ba..824e66d7bf93 100644 --- a/drivers/scsi/ipr.c +++ b/drivers/scsi/ipr.c @@ -3984,13 +3984,12 @@ static ssize_t ipr_store_update_fw(struct device *dev, struct ipr_sglist *sglist; char fname[100]; char *src; - int len, result, dnld_size; + int result, dnld_size; if (!capable(CAP_SYS_ADMIN)) return -EACCES; - len = snprintf(fname, 99, "%s", buf); - fname[len-1] = '\0'; + snprintf(fname, sizeof(fname), "%s", buf); if (request_firmware(&fw_entry, fname, &ioa_cfg->pdev->dev)) { dev_err(&ioa_cfg->pdev->dev, "Firmware file %s not found\n", fname);