[PATCH v2] nvme: avoid NULL pointer dereference in admin queue initialization error path

[Chaitanya Kulkarni]

On 4/22/22 07:40, Smith, Kyle Miller (Nimble Kernel) wrote:
> 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 immediately after the call. However, when we return the error
> message 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 <kyles at hpe.com>
> ---

Looks good.

Reviewed-by: Chaitanya Kulkarni <kch at nvidia.com>

-ck