[PATCH] nvme: avoid NULL pointer dereference in admin queue initialization error path

[Smith, Kyle Miller (Nimble Kernel)]

In nvme_alloc_admin_tags, the admin_q can be set to an error (typically -ENOMEM) if the blk_mq_init_queue call fails to set up the queue, which is checked for immediately after the call. However, when we return the error up the stack to nvme_reset_work the error takes us to nvme_remove_dead_ctrl -> nvme_dev_disable -> nvme_suspend_queue(&dev->queues[0]). Here, we only check that the admin_q is non-NULL, rather than not an error or NULL, and begin quiescing a queue that never existed, leading to bad / NULL pointer dereference.

Signed-off-by: Kyle Smith <mailto:kyles at hpe.com>
---
drivers/nvme/host/pci.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
index 6a99ed680915..2f7510938b18 100644
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -1772,6 +1772,7 @@ static int nvme_alloc_admin_tags(struct nvme_dev *dev)
                               dev->ctrl.admin_q = blk_mq_init_queue(&dev->admin_tagset);
                               if (IS_ERR(dev->ctrl.admin_q)) {
                                               blk_mq_free_tag_set(&dev->admin_tagset);
+                                             dev->ctrl.admin_q = NULL;
                                               return -ENOMEM;
                               }
                               if (!blk_get_queue(dev->ctrl.admin_q)) {