Re: [PATCH] nvme-fc: fix double free of fabrics options when nvme_add_ctrl() fails

On Fri, Aug 14, 2026 at 04:38:34PM +0200, Niklas Cassel wrote:
> ctrl->ctrl.opts also stays valid for the whole teardown now.  That is
> not the bug being fixed, but it removes some fragility around the old
> idiom: nvme_free_ctrl() calls nvme_auth_free() before ->free_ctrl(), and
> ctrl_max_dhchaps() dereferences ctrl->opts without a NULL check when
> ctrl->dhchap_ctxs is set, which nvme-fc permits since NVMF_ALLOWED_OPTS
> allows the dhchap options.  The nvme sysfs attributes that dereference
> ctrl->opts, such as hostnqn and address, evaluate their is_visible()
> test once at device_add() time and stay readable until
> cdev_device_del().

The allocation that ctrl.opts points is freed in this error path, so any
access after that is a use-after-free that needs to be fixed. I think
setting opts to NULL is easier than the proxy locked list check.