Commit d09960b0 authored Oct 10, 2016 by Tahsin Erdogan Committed by Mike Snitzer Oct 18, 2016

dm: free io_barrier after blk_cleanup_queue call



dm_old_request_fn() has paths that access md->io_barrier.  The party
destroying io_barrier should ensure that no future execution of
dm_old_request_fn() is possible.  Move io_barrier destruction to below
blk_cleanup_queue() to ensure this and avoid a NULL pointer crash during
request-based DM device shutdown.

Cc: stable@vger.kernel.org # 4.3+
Signed-off-by: Tahsin Erdogan <tahsin@google.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

parent b052b07c

drivers/md/dm.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -1423,8 +1423,6 @@ static void cleanup_mapped_device(struct mapped_device *md)
		if (md->bs)
		bioset_free(md->bs);

		cleanup_srcu_struct(&md->io_barrier);

		if (md->disk) {
		spin_lock(&_minor_lock);
		md->disk->private_data = NULL;
		@@ -1436,6 +1434,8 @@ static void cleanup_mapped_device(struct mapped_device *md)
		if (md->queue)
		blk_cleanup_queue(md->queue);

		cleanup_srcu_struct(&md->io_barrier);

		if (md->bdev) {
		bdput(md->bdev);
		md->bdev = NULL;

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