4.8-stable review patch. If anyone has any objections, please let me know. ------------------ From: Tahsin Erdogan <tahsin@xxxxxxxxxx> commit d09960b0032174eb493c4c13be5b9c9ef36dc9a7 upstream. 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. Signed-off-by: Tahsin Erdogan <tahsin@xxxxxxxxxx> Signed-off-by: Mike Snitzer <snitzer@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/md/dm.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -1423,8 +1423,6 @@ static void cleanup_mapped_device(struct 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 if (md->queue) blk_cleanup_queue(md->queue); + cleanup_srcu_struct(&md->io_barrier); + if (md->bdev) { bdput(md->bdev); md->bdev = NULL; -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html