From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Shane Seymour" , "Insu Yun" , "Martin K. Petersen" Date: Tue, 29 Mar 2016 20:18:22 +0100 Message-ID: Subject: [PATCH 3.2 41/62] ipr: Fix out-of-bounds null overwrite In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.2.79-rc1 review patch. If anyone has any objections, please let me know. ------------------ 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 Signed-off-by: Ben Hutchings --- drivers/scsi/ipr.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) --- a/drivers/scsi/ipr.c +++ b/drivers/scsi/ipr.c @@ -3736,13 +3736,12 @@ static ssize_t ipr_store_update_fw(struc 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);