2023-10-06 20:18:25

by Kees Cook

Subject: [PATCH] driver core: platform: Annotate struct irq_affinity_devres with __counted_by

Prepare for the coming implementation by GCC and Clang of the __counted_by
attribute. Flexible array members annotated with __counted_by can have
their accesses bounds-checked at run-time via CONFIG_UBSAN_BOUNDS (for
array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family
functions).

As found with Coccinelle[1], add __counted_by for struct
irq_affinity_devres.

Cc: Greg Kroah-Hartman <[email protected]>
Cc: "Rafael J. Wysocki" <[email protected]>
Cc: "Gustavo A. R. Silva" <[email protected]>
Cc: [email protected]
Link: https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci [1]
Signed-off-by: Kees Cook <[email protected]>
---
drivers/base/platform.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/base/platform.c b/drivers/base/platform.c
index 76bfcba25003..07216889d3ba 100644
--- a/drivers/base/platform.c
+++ b/drivers/base/platform.c
@@ -291,7 +291,7 @@ EXPORT_SYMBOL_GPL(platform_irq_count);

struct irq_affinity_devres {
unsigned int count;
- unsigned int irq[];
+ unsigned int irq[] __counted_by(count);
};

static void platform_disable_acpi_irq(struct platform_device *pdev, int index)
--
2.34.1

2023-10-06 20:47:30

by Gustavo A. R. Silva

Subject: Re: [PATCH] driver core: platform: Annotate struct irq_affinity_devres with __counted_by

On 10/6/23 22:17, Kees Cook wrote:
> Prepare for the coming implementation by GCC and Clang of the __counted_by
> attribute. Flexible array members annotated with __counted_by can have
> their accesses bounds-checked at run-time via CONFIG_UBSAN_BOUNDS (for
> array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family
> functions).
>
> As found with Coccinelle[1], add __counted_by for struct
> irq_affinity_devres.
>
> Cc: Greg Kroah-Hartman <[email protected]>
> Cc: "Rafael J. Wysocki" <[email protected]>
> Cc: "Gustavo A. R. Silva" <[email protected]>
> Cc: [email protected]
> Link: https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci [1]
> Signed-off-by: Kees Cook <[email protected]>

Reviewed-by: Gustavo A. R. Silva <[email protected]>

Thanks!
--
Gustavo

> ---
> drivers/base/platform.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/base/platform.c b/drivers/base/platform.c
> index 76bfcba25003..07216889d3ba 100644
> --- a/drivers/base/platform.c
> +++ b/drivers/base/platform.c
> @@ -291,7 +291,7 @@ EXPORT_SYMBOL_GPL(platform_irq_count);
>
> struct irq_affinity_devres {
> unsigned int count;
> - unsigned int irq[];
> + unsigned int irq[] __counted_by(count);
> };
>
> static void platform_disable_acpi_irq(struct platform_device *pdev, int index)