On Fri, Feb 18, 2022 at 2:03 PM Greg KH <greg@xxxxxxxxx> wrote:
>
> On Fri, Feb 18, 2022 at 11:45:29AM +0100, Jens Wiklander wrote:
> > commit aceeafefff736057e8f93f19bbfbef26abd94604 upstream
> >
> > Adds a driver private tee_context to struct optee.
> >
> > The new driver internal tee_context is used when allocating driver
> > private shared memory. This decouples the shared memory object from its
> > original tee_context. This is needed when the life time of such a memory
> > allocation outlives the client tee_context.
> >
> > This patch fixes the problem described below:
> >
> > The addition of a shutdown hook by commit f25889f93184 ("optee: fix tee out
> > of memory failure seen during kexec reboot") introduced a kernel shutdown
> > regression that can be triggered after running the OP-TEE xtest suites.
> >
> > Once the shutdown hook is called it is not possible to communicate any more
> > with the supplicant process because the system is not scheduling task any
> > longer. Thus if the optee driver shutdown path receives a supplicant RPC
> > request from the OP-TEE we will deadlock the kernel's shutdown.
> >
> > Fixes: f25889f93184 ("optee: fix tee out of memory failure seen during kexec reboot")
> > Fixes: 217e0250cccb ("tee: use reference counting for tee_context")
> > Reported-by: Lars Persson <larper@xxxxxxxx>
> > Cc: stable@xxxxxxxxxxxxxxx # 1e2c3ef0496e tee: export teedev_open() and teedev_close_context()
> > Cc: stable@xxxxxxxxxxxxxxx
> > Reviewed-by: Sumit Garg <sumit.garg@xxxxxxxxxx>
> > [JW: backport to 5.16-stable + update commit message]
>
> This and 5.15 backport now queued up.
>
> This needs to go farther back as well, right?
Correct, I'm backporting and testing for the different stable branches.
Cheers,
Jens
>
> thanks
>
> greg k-h
