From mboxrd@z Thu Jan 1 00:00:00 1970 From: maxg@mellanox.com (Max Gurtovoy) Date: Thu, 4 Jan 2018 17:56:13 +0200 Subject: [PATCH 1/2] nvme: Take refcount on transport module when using block device operations Message-ID: <1515081374-22328-1-git-send-email-maxg@mellanox.com> From: Nitzan Carmi The block device is backed by the transport so we must ensure that the related ops driver will not be removed until all external application (e.g. LVM) will release the reference. Otherwise, we might end up referencing freed memory. Reviewed-by: Max Gurtovoy Signed-off-by: Nitzan Carmi --- drivers/nvme/host/core.c | 17 ++++++++++++++--- 1 file changed, 14 insertions(+), 3 deletions(-) diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c index 839650e..cb6b08e 100644 --- a/drivers/nvme/host/core.c +++ b/drivers/nvme/host/core.c @@ -1217,16 +1217,27 @@ static int nvme_open(struct block_device *bdev, fmode_t mode) #ifdef CONFIG_NVME_MULTIPATH /* should never be called due to GENHD_FL_HIDDEN */ if (WARN_ON_ONCE(ns->head->disk)) - return -ENXIO; + goto fail; #endif if (!kref_get_unless_zero(&ns->kref)) - return -ENXIO; + goto fail; + if (!try_module_get(ns->ctrl->ops->module)) + goto fail_put_ns; + return 0; + +fail_put_ns: + kref_put(&ns->kref, nvme_free_ns); +fail: + return -ENXIO; } static void nvme_release(struct gendisk *disk, fmode_t mode) { - nvme_put_ns(disk->private_data); + struct nvme_ns *ns = disk->private_data; + + module_put(ns->ctrl->ops->module); + nvme_put_ns(ns); } static int nvme_getgeo(struct block_device *bdev, struct hd_geometry *geo) -- 1.8.3.1