2022-04-22 20:29:51

by Rafael J. Wysocki

Subject: [PATCH] ACPI: bus: Avoid non-ACPI device objects in walks over children

From: Rafael J. Wysocki <[email protected]>

When walking the children of an ACPI device, take extra care to avoid
using to_acpi_device() on the ones that are not ACPI devices, because
that may lead to out-of-bounds access and memory corruption.

While at it, make the function passed to acpi_dev_for_each_child()
take a struct acpi_device pointer argument (instead of a struct device
one), so it is more straightforward to use.

Fixes: b7dd6298db81 ("ACPI: PM: Introduce acpi_dev_power_up_children_with_adr()")
Reported-by: kernel test robot <[email protected]>
BugLink: https://lore.kernel.org/lkml/20220420064725.GB16310@xsang-OptiPlex-9020/
Signed-off-by: Rafael J. Wysocki <[email protected]>
---

The commit being fixed is present in linux-next.

---
drivers/acpi/bus.c | 24 ++++++++++++++++++++++--
drivers/acpi/device_pm.c | 5 +----
include/acpi/acpi_bus.h | 2 +-
3 files changed, 24 insertions(+), 7 deletions(-)

Index: linux-pm/drivers/acpi/bus.c
===================================================================
--- linux-pm.orig/drivers/acpi/bus.c
+++ linux-pm/drivers/acpi/bus.c
@@ -1070,10 +1070,30 @@ int acpi_bus_for_each_dev(int (*fn)(stru
}
EXPORT_SYMBOL_GPL(acpi_bus_for_each_dev);

+struct acpi_dev_walk_context {
+ int (*fn)(struct acpi_device *, void *);
+ void *data;
+};
+
+static int acpi_dev_for_one_check(struct device *dev, void *context)
+{
+ struct acpi_dev_walk_context *adwc = context;
+
+ if (dev->bus != &acpi_bus_type)
+ return 0;
+
+ return adwc->fn(to_acpi_device(dev), adwc->data);
+}
+
int acpi_dev_for_each_child(struct acpi_device *adev,
- int (*fn)(struct device *, void *), void *data)
+ int (*fn)(struct acpi_device *, void *), void *data)
{
- return device_for_each_child(&adev->dev, data, fn);
+ struct acpi_dev_walk_context adwc = {
+ .fn = fn,
+ .data = data,
+ };
+
+ return device_for_each_child(&adev->dev, &adwc, acpi_dev_for_one_check);
}

/* --------------------------------------------------------------------------
Index: linux-pm/include/acpi/acpi_bus.h
===================================================================
--- linux-pm.orig/include/acpi/acpi_bus.h
+++ linux-pm/include/acpi/acpi_bus.h
@@ -482,7 +482,7 @@ extern struct bus_type acpi_bus_type;

int acpi_bus_for_each_dev(int (*fn)(struct device *, void *), void *data);
int acpi_dev_for_each_child(struct acpi_device *adev,
- int (*fn)(struct device *, void *), void *data);
+ int (*fn)(struct acpi_device *, void *), void *data);

/*
* Events
Index: linux-pm/drivers/acpi/device_pm.c
===================================================================
--- linux-pm.orig/drivers/acpi/device_pm.c
+++ linux-pm/drivers/acpi/device_pm.c
@@ -429,11 +429,8 @@ bool acpi_bus_power_manageable(acpi_hand
}
EXPORT_SYMBOL(acpi_bus_power_manageable);

-static int acpi_power_up_if_adr_present(struct device *dev, void *not_used)
+static int acpi_power_up_if_adr_present(struct acpi_device *adev, void *not_used)
{
- struct acpi_device *adev;
-
- adev = to_acpi_device(dev);
if (!(adev->flags.power_manageable && adev->pnp.type.bus_address))
return 0;

2022-04-22 21:56:23

by Mika Westerberg

Subject: Re: [PATCH] ACPI: bus: Avoid non-ACPI device objects in walks over children

Hi Rafael,

On Fri, Apr 22, 2022 at 05:13:48PM +0200, Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki <[email protected]>
>
> When walking the children of an ACPI device, take extra care to avoid
> using to_acpi_device() on the ones that are not ACPI devices, because
> that may lead to out-of-bounds access and memory corruption.
>
> While at it, make the function passed to acpi_dev_for_each_child()
> take a struct acpi_device pointer argument (instead of a struct device
> one), so it is more straightforward to use.
>
> Fixes: b7dd6298db81 ("ACPI: PM: Introduce acpi_dev_power_up_children_with_adr()")
> Reported-by: kernel test robot <[email protected]>
> BugLink: https://lore.kernel.org/lkml/20220420064725.GB16310@xsang-OptiPlex-9020/
> Signed-off-by: Rafael J. Wysocki <[email protected]>
> ---
>
> The commit being fixed is present in linux-next.
>
> ---
> drivers/acpi/bus.c | 24 ++++++++++++++++++++++--
> drivers/acpi/device_pm.c | 5 +----
> include/acpi/acpi_bus.h | 2 +-
> 3 files changed, 24 insertions(+), 7 deletions(-)
>
> Index: linux-pm/drivers/acpi/bus.c
> ===================================================================
> --- linux-pm.orig/drivers/acpi/bus.c
> +++ linux-pm/drivers/acpi/bus.c
> @@ -1070,10 +1070,30 @@ int acpi_bus_for_each_dev(int (*fn)(stru
> }
> EXPORT_SYMBOL_GPL(acpi_bus_for_each_dev);
>
> +struct acpi_dev_walk_context {
> + int (*fn)(struct acpi_device *, void *);
> + void *data;
> +};
> +
> +static int acpi_dev_for_one_check(struct device *dev, void *context)
> +{
> + struct acpi_dev_walk_context *adwc = context;
> +
> + if (dev->bus != &acpi_bus_type)
> + return 0;

I wonder if it make sense to add dev_is_acpi() that does the above
analoguos to dev_is_pci()?

Regardless of that,

Reviewed-by: Mika Westerberg <[email protected]>