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

From: Gustavo A. R. Silva
Date: Fri Oct 06 2023 - 16:47:04 EST




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 <gregkh@xxxxxxxxxxxxxxxxxxx>
Cc: "Rafael J. Wysocki" <rafael@xxxxxxxxxx>
Cc: "Gustavo A. R. Silva" <gustavoars@xxxxxxxxxx>
Cc: linux-hardening@xxxxxxxxxxxxxxx
Link: https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci [1]
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>

Reviewed-by: Gustavo A. R. Silva <gustavoars@xxxxxxxxxx>

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)