Re: [PATCH] clk: Fix referring to wrong pointer in devm_clk_release()

[Kunihiko Hayashi]

Hi Uwe,

Thank you for pointing out.

On 2022/06/23 16:06, Uwe Kleine-König wrote:
> Hello,
>
> On Thu, Jun 23, 2022 at 10:02:22AM +0900, Kunihiko Hayashi wrote:
> > At bind phase, __devm_clk_get() calls devres_alloc() to allocate devres,
> > and dr->data is treated as a variable "state".
> >
> > At unbind phase, release_nodes() calls devm_clk_release() specified by
> > devres_alloc().
> >
> > The argument "res" of devm_clk_release() is dr->data, and this entity is
> > "state", however in devm_clk_release(), "*res" is treated as "state",
> > resulting in pointer inconsistency.
> >
> > Unbinding a driver caused a panic.
> >
> >      Unable to handle kernel execute from non-executable memory
> >      at virtual address ffff000100236810
> >      ...
> >      pc : 0xffff000100236810
> >      lr : devm_clk_release+0x6c/0x9c
> >      ...
> >      Call trace:
> >       0xffff000100236810
> >       release_nodes+0xb0/0x150
> >       devres_release_all+0x94/0xf8
> >       device_unbind_cleanup+0x20/0x70
> >       device_release_driver_internal+0x114/0x1a0
> >       device_driver_detach+0x20/0x30
> >
> > Cc: Uwe Kleine-König <u.kleine-koenig@xxxxxxxxxxxxxx>
> > Fixes: abae8e57e49a ("clk: generalize devm_clk_get() a bit")
> > Signed-off-by: Kunihiko Hayashi <hayashi.kunihiko@xxxxxxxxxxxxx>
>
> This is already fixed in clk-next:
>
> 	https://git.kernel.org/pub/scm/linux/kernel/git/clk/linux.git/commit/?h=clk-next&id=8b3d743fc9e2542822826890b482afabf0e7522a

Sorry for not finding the fix patch and duplicating it.
I'm waiting for it to be merged.

Thank you,

---
Best Regards
Kunihiko Hayashi