Re: [PATCH 4/4] nvme: re-check security protocol support after reset
On Fri, Feb 17, 2017 at 09:55:51AM -0700, Scott Bauer wrote: > I'm working on it now. Do you want a diff like Keith did or a separate patch? Please make it a proper patch that applies on top of my patches 1-3 (where 3 really is yours anyway). I'll respin 4 with the updates from Keith on top of 1-3 + your patch then.
Re: [PATCH 4/4] nvme: re-check security protocol support after reset
On Fri, Feb 17, 2017 at 06:01:28PM +0100, Christoph Hellwig wrote:
> On Fri, Feb 17, 2017 at 10:26:51AM -0500, Keith Busch wrote:
> > On Fri, Feb 17, 2017 at 01:59:41PM +0100, Christoph Hellwig wrote:
> > > @@ -1789,7 +1789,8 @@ static void nvme_reset_work(struct work_struct
> > > *work)
> > > if (result)
> > > goto out;
> > >
> > > - if ((dev->ctrl.oacs & NVME_CTRL_OACS_SEC_SUPP) && !dev->ctrl.opal_dev) {
> > > + kfree(dev->ctrl.opal_dev);
> > > + if (dev->ctrl.oacs & NVME_CTRL_OACS_SEC_SUPP) {
> > > dev->ctrl.opal_dev =
> > > init_opal_dev(>ctrl, _sec_submit);
> > > }
> >
> > A couple things.
> >
> > This has a use-after-free in opal_unlock_from_suspend if the nvme
> > device had an opal_dev before, but no longer support the capability
> > after resume. So you'd want to set ctrl.opal_dev to NULL after the free.
> >
> > But we don't want to unconditionally free it anyway during resume
> > since opal_unlock_from_suspend requires the exisiting opal_dev state
> > information saved in the 'unlk_list'.
> >
> > Something like this instead:
>
> Yes, that looks fine to me. We'll probably also need the additional
> fixup Scott pointed out.
I'm working on it now. Do you want a diff like Keith did or a separate patch?
Re: [PATCH 4/4] nvme: re-check security protocol support after reset
On Fri, Feb 17, 2017 at 10:26:51AM -0500, Keith Busch wrote:
> On Fri, Feb 17, 2017 at 01:59:41PM +0100, Christoph Hellwig wrote:
> > @@ -1789,7 +1789,8 @@ static void nvme_reset_work(struct work_struct *work)
> > if (result)
> > goto out;
> >
> > - if ((dev->ctrl.oacs & NVME_CTRL_OACS_SEC_SUPP) && !dev->ctrl.opal_dev) {
> > + kfree(dev->ctrl.opal_dev);
> > + if (dev->ctrl.oacs & NVME_CTRL_OACS_SEC_SUPP) {
> > dev->ctrl.opal_dev =
> > init_opal_dev(>ctrl, _sec_submit);
> > }
>
> A couple things.
>
> This has a use-after-free in opal_unlock_from_suspend if the nvme
> device had an opal_dev before, but no longer support the capability
> after resume. So you'd want to set ctrl.opal_dev to NULL after the free.
>
> But we don't want to unconditionally free it anyway during resume
> since opal_unlock_from_suspend requires the exisiting opal_dev state
> information saved in the 'unlk_list'.
>
> Something like this instead:
Yes, that looks fine to me. We'll probably also need the additional
fixup Scott pointed out.
Re: [PATCH 4/4] nvme: re-check security protocol support after reset
On Fri, Feb 17, 2017 at 10:26:51AM -0500, Keith Busch wrote:
> On Fri, Feb 17, 2017 at 01:59:41PM +0100, Christoph Hellwig wrote:
> > @@ -1789,7 +1789,8 @@ static void nvme_reset_work(struct work_struct *work)
> > if (result)
> > goto out;
> >
> > - if ((dev->ctrl.oacs & NVME_CTRL_OACS_SEC_SUPP) && !dev->ctrl.opal_dev) {
> > + kfree(dev->ctrl.opal_dev);
> > + if (dev->ctrl.oacs & NVME_CTRL_OACS_SEC_SUPP) {
> > dev->ctrl.opal_dev =
> > init_opal_dev(>ctrl, _sec_submit);
> > }
>
> A couple things.
>
> This has a use-after-free in opal_unlock_from_suspend if the nvme
> device had an opal_dev before, but no longer support the capability
> after resume. So you'd want to set ctrl.opal_dev to NULL after the free.
>
> But we don't want to unconditionally free it anyway during resume
> since opal_unlock_from_suspend requires the exisiting opal_dev state
> information saved in the 'unlk_list'.
>
> Something like this instead:
>
> ---
> diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
> index ddc51ad..8fa6be9 100644
> --- a/drivers/nvme/host/pci.c
> +++ b/drivers/nvme/host/pci.c
> @@ -1789,13 +1789,17 @@ static void nvme_reset_work(struct work_struct *work)
> if (result)
> goto out;
>
> - if ((dev->ctrl.oacs & NVME_CTRL_OACS_SEC_SUPP) && !dev->ctrl.opal_dev) {
> - dev->ctrl.opal_dev =
> - init_opal_dev(>ctrl, _sec_submit);
> + if (dev->ctrl.oacs & NVME_CTRL_OACS_SEC_SUPP)
> + if (was_suspend && dev->ctrl.opal_dev)
> + opal_unlock_from_suspend(dev->ctrl.opal_dev);
> + else if (!dev->ctrl.opal_dev)
> + dev->ctrl.opal_dev =
> + init_opal_dev(>ctrl, _sec_submit);
> + } else {
> + kfree(dev->ctrl.opal_dev);
> + dev->ctrl.opal_dev = NULL;
Keith's comments made me realize something even deeper as well. Assuming the
firmware
changed and we no longer support security commands we need to free the opal_dev
structure
like we're doing but there is a possiblity that there were saved ranges in the
structure
that we need to free as well. If the user had previously told the kernel to
unlock 5
ranges coming out of a suspend there are 5 structures we need to free inside
the opal_dev
before we free the opal dev. We'll need to re-introduce free_opal_dev() in the
opal code
like we had a while back.
Re: [PATCH 4/4] nvme: re-check security protocol support after reset
On Fri, Feb 17, 2017 at 01:59:41PM +0100, Christoph Hellwig wrote:
> @@ -1789,7 +1789,8 @@ static void nvme_reset_work(struct work_struct *work)
> if (result)
> goto out;
>
> - if ((dev->ctrl.oacs & NVME_CTRL_OACS_SEC_SUPP) && !dev->ctrl.opal_dev) {
> + kfree(dev->ctrl.opal_dev);
> + if (dev->ctrl.oacs & NVME_CTRL_OACS_SEC_SUPP) {
> dev->ctrl.opal_dev =
> init_opal_dev(>ctrl, _sec_submit);
> }
A couple things.
This has a use-after-free in opal_unlock_from_suspend if the nvme
device had an opal_dev before, but no longer support the capability
after resume. So you'd want to set ctrl.opal_dev to NULL after the free.
But we don't want to unconditionally free it anyway during resume
since opal_unlock_from_suspend requires the exisiting opal_dev state
information saved in the 'unlk_list'.
Something like this instead:
---
diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
index ddc51ad..8fa6be9 100644
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -1789,13 +1789,17 @@ static void nvme_reset_work(struct work_struct *work)
if (result)
goto out;
- if ((dev->ctrl.oacs & NVME_CTRL_OACS_SEC_SUPP) && !dev->ctrl.opal_dev) {
- dev->ctrl.opal_dev =
- init_opal_dev(>ctrl, _sec_submit);
+ if (dev->ctrl.oacs & NVME_CTRL_OACS_SEC_SUPP)
+ if (was_suspend && dev->ctrl.opal_dev)
+ opal_unlock_from_suspend(dev->ctrl.opal_dev);
+ else if (!dev->ctrl.opal_dev)
+ dev->ctrl.opal_dev =
+ init_opal_dev(>ctrl, _sec_submit);
+ } else {
+ kfree(dev->ctrl.opal_dev);
+ dev->ctrl.opal_dev = NULL;
}
- if (was_suspend)
- opal_unlock_from_suspend(dev->ctrl.opal_dev);
result = nvme_setup_io_queues(dev);
if (result)
--
