Re: [PATCH] PCI: hv: Annotate struct hv_dr_state with __counted_by

From: Gustavo A. R. Silva
Date: Sat Sep 23 2023 - 04:59:15 EST


On Fri, Sep 22, 2023 at 10:52:57AM -0700, 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 checking 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 hv_dr_state.
>
> [1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci
>
> Cc: "K. Y. Srinivasan" <kys@xxxxxxxxxxxxx>
> Cc: Haiyang Zhang <haiyangz@xxxxxxxxxxxxx>
> Cc: Wei Liu <wei.liu@xxxxxxxxxx>
> Cc: Dexuan Cui <decui@xxxxxxxxxxxxx>
> Cc: Lorenzo Pieralisi <lpieralisi@xxxxxxxxxx>
> Cc: "Krzysztof Wilczyński" <kw@xxxxxxxxx>
> Cc: Rob Herring <robh@xxxxxxxxxx>
> Cc: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
> Cc: linux-hyperv@xxxxxxxxxxxxxxx
> Cc: linux-pci@xxxxxxxxxxxxxxx
> Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>

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

Thanks
--
Gustavo

> ---
> drivers/pci/controller/pci-hyperv.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/pci/controller/pci-hyperv.c b/drivers/pci/controller/pci-hyperv.c
> index bed3cefdaf19..30c7dfeccb16 100644
> --- a/drivers/pci/controller/pci-hyperv.c
> +++ b/drivers/pci/controller/pci-hyperv.c
> @@ -545,7 +545,7 @@ struct hv_pcidev_description {
> struct hv_dr_state {
> struct list_head list_entry;
> u32 device_count;
> - struct hv_pcidev_description func[];
> + struct hv_pcidev_description func[] __counted_by(device_count);
> };
>
> struct hv_pci_dev {
> --
> 2.34.1
>
>