From 9b4231bf995996d6459c57959ead5a1829ff2c57 Mon Sep 17 00:00:00 2001 From: Akinobu Mita Date: Sun, 25 May 2014 21:43:34 +0900 Subject: block: fix SG_[GS]ET_RESERVED_SIZE ioctl when max_sectors is huge 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 Cc: "James E.J. Bottomley" Cc: Douglas Gilbert Cc: linux-scsi@vger.kernel.org Reviewed-by: Christoph Hellwig Signed-off-by: Jens Axboe --- block/scsi_ioctl.c | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-) (limited to 'block/scsi_ioctl.c') diff --git a/block/scsi_ioctl.c b/block/scsi_ioctl.c index 14695c6221c8..bda1497add4c 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; } -- cgit v1.2.3