[PATCH] clk: fix possible null pointer dereference

[PATCH] clk: fix possible null pointer dereference

[Stanimir Varbanov]

The commit 646cafc6 (clk: Change clk_ops->determine_rate to
return a clk_hw as the best parent) opens a possibility for
null pointer dereference, fix this.

Signed-off-by: Stanimir Varbanov <svarbanov@mm-sol.com>
---
 drivers/clk/clk.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
index f4963b7..d48ac71 100644
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -1366,7 +1366,7 @@ static struct clk *clk_calc_new_rates(struct clk *clk, unsigned long rate)
 		new_rate = clk->ops->determine_rate(clk->hw, rate,
 						    &best_parent_rate,
 						    &parent_hw);
-		parent = parent_hw->clk;
+		parent = parent_hw ? parent_hw->clk : NULL;
 	} else if (clk->ops->round_rate) {
 		new_rate = clk->ops->round_rate(clk->hw, rate,
 						&best_parent_rate);
-- 
1.7.0.4

Re: [PATCH] clk: fix possible null pointer dereference

[Stephen Boyd]

On 01/05/2015 08:04 AM, Stanimir Varbanov wrote:
> The commit 646cafc6 (clk: Change clk_ops->determine_rate to
> return a clk_hw as the best parent) opens a possibility for
> null pointer dereference, fix this.
>
> Signed-off-by: Stanimir Varbanov <svarbanov@mm-sol.com>

Yep. Hopefully we can clean this all up soon.

Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>

> ---
>  drivers/clk/clk.c |    2 +-
>  1 files changed, 1 insertions(+), 1 deletions(-)
>
> diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
> index f4963b7..d48ac71 100644
> --- a/drivers/clk/clk.c
> +++ b/drivers/clk/clk.c
> @@ -1366,7 +1366,7 @@ static struct clk *clk_calc_new_rates(struct clk *clk, unsigned long rate)
>  		new_rate = clk->ops->determine_rate(clk->hw, rate,
>  						    &best_parent_rate,
>  						    &parent_hw);
> -		parent = parent_hw->clk;
> +		parent = parent_hw ? parent_hw->clk : NULL;
>  	} else if (clk->ops->round_rate) {
>  		new_rate = clk->ops->round_rate(clk->hw, rate,
>  						&best_parent_rate);


-- 
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
a Linux Foundation Collaborative Project

Re: [PATCH] clk: fix possible null pointer dereference

[Mike Turquette]

Quoting Stephen Boyd (2015-01-05 11:34:32)
> On 01/05/2015 08:04 AM, Stanimir Varbanov wrote:
> > The commit 646cafc6 (clk: Change clk_ops->determine_rate to
> > return a clk_hw as the best parent) opens a possibility for
> > null pointer dereference, fix this.
> >
> > Signed-off-by: Stanimir Varbanov <svarbanov@mm-sol.com>
> 
> Yep. Hopefully we can clean this all up soon.
> 
> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>

Applied to clk-fixes.

Regards,
Mike

> 
> > ---
> >  drivers/clk/clk.c |    2 +-
> >  1 files changed, 1 insertions(+), 1 deletions(-)
> >
> > diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
> > index f4963b7..d48ac71 100644
> > --- a/drivers/clk/clk.c
> > +++ b/drivers/clk/clk.c
> > @@ -1366,7 +1366,7 @@ static struct clk *clk_calc_new_rates(struct clk *clk, unsigned long rate)
> >               new_rate = clk->ops->determine_rate(clk->hw, rate,
> >                                                   &best_parent_rate,
> >                                                   &parent_hw);
> > -             parent = parent_hw->clk;
> > +             parent = parent_hw ? parent_hw->clk : NULL;
> >       } else if (clk->ops->round_rate) {
> >               new_rate = clk->ops->round_rate(clk->hw, rate,
> >                                               &best_parent_rate);
> 
> 
> -- 
> Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
> a Linux Foundation Collaborative Project
>