From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751911AbaC2O3X (ORCPT ); Sat, 29 Mar 2014 10:29:23 -0400 Received: from mail-pa0-f43.google.com ([209.85.220.43]:35611 "EHLO mail-pa0-f43.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751690AbaC2O2x (ORCPT ); Sat, 29 Mar 2014 10:28:53 -0400 From: Akinobu Mita To: linux-kernel@vger.kernel.org Cc: Akinobu Mita , Jens Axboe Subject: [PATCH] block: fix SG_[GS]ET_RESERVED_SIZE ioctl when max_sectors is huge Date: Sat, 29 Mar 2014 23:28:42 +0900 Message-Id: <1396103322-3519-2-git-send-email-akinobu.mita@gmail.com> X-Mailer: git-send-email 1.8.3.2 In-Reply-To: <1396103322-3519-1-git-send-email-akinobu.mita@gmail.com> References: <1396103322-3519-1-git-send-email-akinobu.mita@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org SG_GET_RESERVED_SIZE and SG_SET_RESERVED_SIZE ioctls access a reserved buffer in bytes as int type. The value needs to be capped at the request queue's max_sectors. But integer overflow is not correctly handled in the calculation when converting max_sectors from sectors to bytes. Signed-off-by: Akinobu Mita Cc: Jens Axboe --- block/scsi_ioctl.c | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-) diff --git a/block/scsi_ioctl.c b/block/scsi_ioctl.c index 2648797..6174bba 100644 --- a/block/scsi_ioctl.c +++ b/block/scsi_ioctl.c @@ -82,9 +82,18 @@ static int sg_set_timeout(struct request_queue *q, int __user *p) return err; } +static int max_sectors_bytes(struct request_queue *q) +{ + unsigned int max_sectors = queue_max_sectors(q); + + max_sectors = min_t(unsigned int, max_sectors, INT_MAX >> 9); + + return max_sectors << 9; +} + static int sg_get_reserved_size(struct request_queue *q, int __user *p) { - unsigned val = min(q->sg_reserved_size, queue_max_sectors(q) << 9); + int val = min_t(int, q->sg_reserved_size, max_sectors_bytes(q)); return put_user(val, p); } @@ -98,10 +107,8 @@ static int sg_set_reserved_size(struct request_queue *q, int __user *p) if (size < 0) return -EINVAL; - if (size > (queue_max_sectors(q) << 9)) - size = queue_max_sectors(q) << 9; - q->sg_reserved_size = size; + q->sg_reserved_size = min(size, max_sectors_bytes(q)); return 0; } -- 1.8.3.2