From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S936247AbdDSO5L (ORCPT ); Wed, 19 Apr 2017 10:57:11 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:51054 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S936268AbdDSO5E (ORCPT ); Wed, 19 Apr 2017 10:57:04 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Steve Magnani , Bart Van Assche , "Martin K. Petersen" Subject: [PATCH 4.4 15/45] scsi: sd: Fix capacity calculation with 32-bit sector_t Date: Wed, 19 Apr 2017 16:55:57 +0200 Message-Id: <20170419141635.387509907@linuxfoundation.org> X-Mailer: git-send-email 2.12.2 In-Reply-To: <20170419141634.793081968@linuxfoundation.org> References: <20170419141634.793081968@linuxfoundation.org> User-Agent: quilt/0.65 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Martin K. Petersen commit 7c856152cb92f8eee2df29ef325a1b1f43161aff upstream. We previously made sure that the reported disk capacity was less than 0xffffffff blocks when the kernel was not compiled with large sector_t support (CONFIG_LBDAF). However, this check assumed that the capacity was reported in units of 512 bytes. Add a sanity check function to ensure that we only enable disks if the entire reported capacity can be expressed in terms of sector_t. Reported-by: Steve Magnani Cc: Bart Van Assche Reviewed-by: Bart Van Assche Signed-off-by: Martin K. Petersen Signed-off-by: Greg Kroah-Hartman --- drivers/scsi/sd.c | 20 ++++++++++++++++++-- 1 file changed, 18 insertions(+), 2 deletions(-) --- a/drivers/scsi/sd.c +++ b/drivers/scsi/sd.c @@ -2051,6 +2051,22 @@ static void read_capacity_error(struct s #define READ_CAPACITY_RETRIES_ON_RESET 10 +/* + * Ensure that we don't overflow sector_t when CONFIG_LBDAF is not set + * and the reported logical block size is bigger than 512 bytes. Note + * that last_sector is a u64 and therefore logical_to_sectors() is not + * applicable. + */ +static bool sd_addressable_capacity(u64 lba, unsigned int sector_size) +{ + u64 last_sector = (lba + 1ULL) << (ilog2(sector_size) - 9); + + if (sizeof(sector_t) == 4 && last_sector > U32_MAX) + return false; + + return true; +} + static int read_capacity_16(struct scsi_disk *sdkp, struct scsi_device *sdp, unsigned char *buffer) { @@ -2116,7 +2132,7 @@ static int read_capacity_16(struct scsi_ return -ENODEV; } - if ((sizeof(sdkp->capacity) == 4) && (lba >= 0xffffffffULL)) { + if (!sd_addressable_capacity(lba, sector_size)) { sd_printk(KERN_ERR, sdkp, "Too big for this kernel. Use a " "kernel compiled with support for large block " "devices.\n"); @@ -2202,7 +2218,7 @@ static int read_capacity_10(struct scsi_ return sector_size; } - if ((sizeof(sdkp->capacity) == 4) && (lba == 0xffffffff)) { + if (!sd_addressable_capacity(lba, sector_size)) { sd_printk(KERN_ERR, sdkp, "Too big for this kernel. Use a " "kernel compiled with support for large block " "devices.\n");