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: e56f81e0b01e ("dm: refactor ioctl handling")
Reported-by: Junichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index fabd5d8..5df4048 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -603,9 +603,10 @@
{
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 @@
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;