dm: do not reuse dm_blk_ioctl block_device input as local variable

(Ab)using the @bdev passed to dm_blk_ioctl() opens the potential for
targets' .prepare_ioctl to fail if they go on to check the bdev for
!NULL.

Fixes: e56f81e0b0 ("dm: refactor ioctl handling")
Reported-by: Junichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
This commit is contained in:
Mike Snitzer 2015-11-17 14:11:34 -05:00
parent 5bbbfdf685
commit 647a20d5ca
1 changed files with 3 additions and 2 deletions

View File

@ -603,9 +603,10 @@ static int dm_blk_ioctl(struct block_device *bdev, fmode_t mode,
{
struct mapped_device *md = bdev->bd_disk->private_data;
struct dm_target *tgt;
struct block_device *tgt_bdev = NULL;
int srcu_idx, r;
r = dm_get_live_table_for_ioctl(md, &tgt, &bdev, &mode, &srcu_idx);
r = dm_get_live_table_for_ioctl(md, &tgt, &tgt_bdev, &mode, &srcu_idx);
if (r < 0)
return r;
@ -620,7 +621,7 @@ static int dm_blk_ioctl(struct block_device *bdev, fmode_t mode,
goto out;
}
r = __blkdev_driver_ioctl(bdev, mode, cmd, arg);
r = __blkdev_driver_ioctl(tgt_bdev, mode, cmd, arg);
out:
dm_put_live_table(md, srcu_idx);
return r;