Take the client_lock before traversing the clients list at the
pmic_glink_state_notify_clients() function. This is required to keep the
list traversal safe from concurrent modification.

Fixes: 58ef4ece1e41 ("soc: qcom: pmic_glink: Introduce base PMIC GLINK driver")
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
---
 drivers/soc/qcom/pmic_glink.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/soc/qcom/pmic_glink.c b/drivers/soc/qcom/pmic_glink.c
index f913e9bd57ed..c999358771b3 100644
--- a/drivers/soc/qcom/pmic_glink.c
+++ b/drivers/soc/qcom/pmic_glink.c
@@ -168,8 +168,10 @@ static void pmic_glink_state_notify_clients(struct pmic_glink *pg)
 	}
 
 	if (new_state != pg->client_state) {
+		mutex_lock(&pg->client_lock);
 		list_for_each_entry(client, &pg->clients, node)
 			client->pdr_notify(client->priv, new_state);
+		mutex_unlock(&pg->client_lock);
 		pg->client_state = new_state;
 	}
 }

-- 
2.39.2

On Tue, Apr 02, 2024 at 08:07:06PM +0300, Dmitry Baryshkov wrote:
> Take the client_lock before traversing the clients list at the
> pmic_glink_state_notify_clients() function. This is required to keep the
> list traversal safe from concurrent modification.
> 
> Fixes: 58ef4ece1e41 ("soc: qcom: pmic_glink: Introduce base PMIC GLINK driver")
> Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
> ---
>  drivers/soc/qcom/pmic_glink.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/soc/qcom/pmic_glink.c b/drivers/soc/qcom/pmic_glink.c
> index f913e9bd57ed..c999358771b3 100644
> --- a/drivers/soc/qcom/pmic_glink.c
> +++ b/drivers/soc/qcom/pmic_glink.c
> @@ -168,8 +168,10 @@ static void pmic_glink_state_notify_clients(struct pmic_glink *pg)
>  	}

Does pmic_glink_rpmsg_callback() deserve similar locking when traversing
the clients list?

>  
>  	if (new_state != pg->client_state) {
> +		mutex_lock(&pg->client_lock);
>  		list_for_each_entry(client, &pg->clients, node)
>  			client->pdr_notify(client->priv, new_state);
> +		mutex_unlock(&pg->client_lock);
>  		pg->client_state = new_state;
>  	}
>  }
> 
> -- 
> 2.39.2
> 
>

On Tue, 2 Apr 2024 at 20:56, Andrew Halaney <ahalaney@redhat.com> wrote:
>
> On Tue, Apr 02, 2024 at 08:07:06PM +0300, Dmitry Baryshkov wrote:
> > Take the client_lock before traversing the clients list at the
> > pmic_glink_state_notify_clients() function. This is required to keep the
> > list traversal safe from concurrent modification.
> >
> > Fixes: 58ef4ece1e41 ("soc: qcom: pmic_glink: Introduce base PMIC GLINK driver")
> > Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
> > ---
> >  drivers/soc/qcom/pmic_glink.c | 2 ++
> >  1 file changed, 2 insertions(+)
> >
> > diff --git a/drivers/soc/qcom/pmic_glink.c b/drivers/soc/qcom/pmic_glink.c
> > index f913e9bd57ed..c999358771b3 100644
> > --- a/drivers/soc/qcom/pmic_glink.c
> > +++ b/drivers/soc/qcom/pmic_glink.c
> > @@ -168,8 +168,10 @@ static void pmic_glink_state_notify_clients(struct pmic_glink *pg)
> >       }
>
> Does pmic_glink_rpmsg_callback() deserve similar locking when traversing
> the clients list?

True. Will fix in v2.

>
> >
> >       if (new_state != pg->client_state) {
> > +             mutex_lock(&pg->client_lock);
> >               list_for_each_entry(client, &pg->clients, node)
> >                       client->pdr_notify(client->priv, new_state);
> > +             mutex_unlock(&pg->client_lock);
> >               pg->client_state = new_state;
> >       }
> >  }
> >
> > --
> > 2.39.2
> >
> >
>


-- 
With best wishes
Dmitry