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 <akinobu.mita@gmail.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: "James E.J. Bottomley" <JBottomley@parallels.com>
Cc: Douglas Gilbert <dgilbert@interlog.com>
Cc: linux-scsi@vger.kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
This commit is contained in:
Akinobu Mita 2014-05-25 21:43:34 +09:00 committed by Jens Axboe
parent 63f2649659
commit 9b4231bf99
1 changed files with 11 additions and 4 deletions

View File

@ -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;
}