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authorAkinobu Mita <akinobu.mita@gmail.com>2014-05-25 21:43:33 +0900
committerJens Axboe <axboe@fb.com>2014-07-01 10:43:07 -0600
commit63f264965947ac6299452711f614f086955b2515 (patch)
tree20050c8d77eb14fbb1439eb9af85916bf87f7dd2
parent16e1556526241b893d40b01d1c1b14a4e83ee499 (diff)
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>
-rw-r--r--block/compat_ioctl.c6
-rw-r--r--block/ioctl.c5
2 files changed, 8 insertions, 3 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)));
diff --git a/block/ioctl.c b/block/ioctl.c
index 7d5c3b20af45..d6cda8147c91 100644
--- a/block/ioctl.c
+++ b/block/ioctl.c
@@ -278,6 +278,7 @@ int blkdev_ioctl(struct block_device *bdev, fmode_t mode, unsigned cmd,
struct backing_dev_info *bdi;
loff_t size;
int ret, n;
+ unsigned int max_sectors;
switch(cmd) {
case BLKFLSBUF:
@@ -375,7 +376,9 @@ int blkdev_ioctl(struct block_device *bdev, fmode_t mode, unsigned cmd,
case BLKDISCARDZEROES:
return put_uint(arg, bdev_discard_zeroes_data(bdev));
case BLKSECTGET:
- return 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 put_ushort(arg, max_sectors);
case BLKROTATIONAL:
return put_ushort(arg, !blk_queue_nonrot(bdev_get_queue(bdev)));
case BLKRASET: