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| author | Akinobu Mita <akinobu.mita@gmail.com> | 2014-05-25 21:43:33 +0900 |
|---|---|---|
| committer | Jens Axboe <axboe@fb.com> | 2014-07-01 10:43:07 -0600 |
| commit | 63f264965947ac6299452711f614f086955b2515 (patch) | |
| tree | 20050c8d77eb14fbb1439eb9af85916bf87f7dd2 /block/compat_ioctl.c | |
| parent | 16e1556526241b893d40b01d1c1b14a4e83ee499 (diff) | |
| download | linux-63f264965947ac6299452711f614f086955b2515.tar.gz linux-63f264965947ac6299452711f614f086955b2515.tar.bz2 linux-63f264965947ac6299452711f614f086955b2515.zip | |
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>
Diffstat (limited to 'block/compat_ioctl.c')
| -rw-r--r-- | block/compat_ioctl.c | 6 |
1 files changed, 4 insertions, 2 deletions
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))); |