block: fix BLKSECTGET ioctl when max_sectors is greater than USHRT_MAX
authorAkinobu Mita <akinobu.mita@gmail.com>
Sun, 25 May 2014 12:43:33 +0000 (21:43 +0900)
committerJens Axboe <axboe@fb.com>
Tue, 1 Jul 2014 16:43:07 +0000 (10:43 -0600)
commit63f264965947ac6299452711f614f086955b2515
tree20050c8d77eb14fbb1439eb9af85916bf87f7dd2
parent16e1556526241b893d40b01d1c1b14a4e83ee499
block: fix BLKSECTGET ioctl when max_sectors is greater than USHRT_MAX

BLKSECTGET ioctl loads the request queue's max_sectors as unsigned
short value to the argument pointer.  So if the max_sector is greater
than USHRT_MAX, the upper 16 bits of that is just discarded.

In such case, USHRT_MAX is more preferable than the lower 16 bits of
max_sectors.

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>
block/compat_ioctl.c
block/ioctl.c