[PATCH] ARM: EXYNOS: Fix dereference of ERR_PTR returned by of_genpd_get_from_provider

[PATCH] ARM: EXYNOS: Fix dereference of ERR_PTR returned by of_genpd_get_from_provider

[Krzysztof Kozlowski]

ERR_PTR was dereferenced during sub domain parsing, if parent domain
could not be obtained (because of invalid phandle or deferred
registration of parent domain).

The Exynos power domain code checked whether
of_genpd_get_from_provider() returned NULL and in that case it skipped
that power domain node. However this function returns ERR_PTR or valid
pointer, not NULL.

Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Cc: <stable@vger.kernel.org>
Fixes: 0f7807518fe1 ("ARM: EXYNOS: add support for sub-power domains")

---

The patchset is rebased on top of my fixes for pm_domains.c to avoid the
conflicts:
https://lkml.org/lkml/2015/3/27/321
---
 arch/arm/mach-exynos/pm_domains.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/arm/mach-exynos/pm_domains.c b/arch/arm/mach-exynos/pm_domains.c
index 1a90c5da2fd7..440324c94d28 100644
--- a/arch/arm/mach-exynos/pm_domains.c
+++ b/arch/arm/mach-exynos/pm_domains.c
@@ -209,7 +209,7 @@ no_clk:
 		args.np = np;
 		args.args_count = 0;
 		child_domain = of_genpd_get_from_provider(&args);
-		if (!child_domain)
+		if (IS_ERR(child_domain))
 			goto next_pd;
 
 		if (of_parse_phandle_with_args(np, "power-domains",
@@ -217,7 +217,7 @@ no_clk:
 			goto next_pd;
 
 		parent_domain = of_genpd_get_from_provider(&args);
-		if (!parent_domain)
+		if (IS_ERR(parent_domain))
 			goto next_pd;
 
 		if (pm_genpd_add_subdomain(parent_domain, child_domain))
-- 
1.9.1

[PATCH] ARM: EXYNOS: Fix dereference of ERR_PTR returned byof_genpd_get_from_provider

[Kukjin Kim]

On 05/13/15 12:17, Krzysztof Kozlowski wrote:
> ERR_PTR was dereferenced during sub domain parsing, if parent domain
> could not be obtained (because of invalid phandle or deferred
> registration of parent domain).
> 
> The Exynos power domain code checked whether
> of_genpd_get_from_provider() returned NULL and in that case it skipped
> that power domain node. However this function returns ERR_PTR or valid
> pointer, not NULL.
> 
> Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
> Cc: <stable@vger.kernel.org>

Maybe [4.0+]? but as you mentioned this patch has a dependency with
Patch "ARM: EXYNOS: Add missing of_node_put() when parsing power domain"
and it means this cannot be applied into stable tree...

So I'll apply this patch firstly then please re-submit them I've missed
before based on samsung tree. I think, it would be better...

> Fixes: 0f7807518fe1 ("ARM: EXYNOS: add support for sub-power domains")
> 
> ---
> 
> The patchset is rebased on top of my fixes for pm_domains.c to avoid the
> conflicts:
> https://lkml.org/lkml/2015/3/27/321
> ---
>  arch/arm/mach-exynos/pm_domains.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/arch/arm/mach-exynos/pm_domains.c b/arch/arm/mach-exynos/pm_domains.c
> index 1a90c5da2fd7..440324c94d28 100644
> --- a/arch/arm/mach-exynos/pm_domains.c
> +++ b/arch/arm/mach-exynos/pm_domains.c
> @@ -209,7 +209,7 @@ no_clk:
>  		args.np = np;
>  		args.args_count = 0;
>  		child_domain = of_genpd_get_from_provider(&args);
> -		if (!child_domain)
> +		if (IS_ERR(child_domain))
>  			goto next_pd;
>  
>  		if (of_parse_phandle_with_args(np, "power-domains",
> @@ -217,7 +217,7 @@ no_clk:
>  			goto next_pd;
>  
>  		parent_domain = of_genpd_get_from_provider(&args);
> -		if (!parent_domain)
> +		if (IS_ERR(parent_domain))
>  			goto next_pd;
>  
>  		if (pm_genpd_add_subdomain(parent_domain, child_domain))

Applied into fixes with resolving conflict.

Thanks,
Kukjin

[PATCH] ARM: EXYNOS: Fix dereference of ERR_PTR returned byof_genpd_get_from_provider

[Krzysztof Kozlowski]

2015-05-13 17:44 GMT+09:00 Kukjin Kim <kgene@kernel.org>:
> On 05/13/15 12:17, Krzysztof Kozlowski wrote:
>> ERR_PTR was dereferenced during sub domain parsing, if parent domain
>> could not be obtained (because of invalid phandle or deferred
>> registration of parent domain).
>>
>> The Exynos power domain code checked whether
>> of_genpd_get_from_provider() returned NULL and in that case it skipped
>> that power domain node. However this function returns ERR_PTR or valid
>> pointer, not NULL.
>>
>> Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
>> Cc: <stable@vger.kernel.org>
>
> Maybe [4.0+]? but as you mentioned this patch has a dependency with

Tag fixes with commit ID is sufficient for stable backporting.

> Patch "ARM: EXYNOS: Add missing of_node_put() when parsing power domain"
> and it means this cannot be applied into stable tree...
>
> So I'll apply this patch firstly then please re-submit them I've missed
> before based on samsung tree. I think, it would be better...
>
>> Fixes: 0f7807518fe1 ("ARM: EXYNOS: add support for sub-power domains")

I will get an notification when this patch won't apply to stable tree
(like v4.0) because of conflicts. Then usually I fix/rebase the patch
and send to the stable tree. So don't worry about this, I will handle
the backport.

Best regards,
Krzysztof