From 63f264965947ac6299452711f614f086955b2515 Mon Sep 17 00:00:00 2001 From: Akinobu Mita Date: Sun, 25 May 2014 21:43:33 +0900 Subject: 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 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/compat_ioctl.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) (limited to 'block/compat_ioctl.c') diff --git a/block/compat_ioctl.c b/block/compat_ioctl.c index fbd5a67cb773..e0393cd2ea7f 100644 --- a/block/compat_ioctl.c +++ b/block/compat_ioctl.c @@ -663,6 +663,7 @@ long compat_blkdev_ioctl(struct file *file, unsigned cmd, unsigned long arg) fmode_t mode = file->f_mode; struct backing_dev_info *bdi; loff_t size; + unsigned int max_sectors; /* * O_NDELAY can be altered using fcntl(.., F_SETFL, ..), so we have @@ -718,8 +719,9 @@ long compat_blkdev_ioctl(struct file *file, unsigned cmd, unsigned long arg) case BLKSSZGET: /* get block device hardware sector size */ return compat_put_int(arg, bdev_logical_block_size(bdev)); case BLKSECTGET: - return compat_put_ushort(arg, - queue_max_sectors(bdev_get_queue(bdev))); + max_sectors = min_t(unsigned int, USHRT_MAX, + queue_max_sectors(bdev_get_queue(bdev))); + return compat_put_ushort(arg, max_sectors); case BLKROTATIONAL: return compat_put_ushort(arg, !blk_queue_nonrot(bdev_get_queue(bdev))); -- cgit v1.2.3