2023-09-22 20:56:05

by Kees Cook

Subject: [PATCH] PCI: hv: Annotate struct hv_dr_state 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 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" <[email protected]>
Cc: Haiyang Zhang <[email protected]>
Cc: Wei Liu <[email protected]>
Cc: Dexuan Cui <[email protected]>
Cc: Lorenzo Pieralisi <[email protected]>
Cc: "Krzysztof Wilczyński" <[email protected]>
Cc: Rob Herring <[email protected]>
Cc: Bjorn Helgaas <[email protected]>
Cc: [email protected]
Cc: [email protected]
Signed-off-by: Kees Cook <[email protected]>
---
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

2023-09-23 08:59:20

by Gustavo A. R. Silva

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

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" <[email protected]>
> Cc: Haiyang Zhang <[email protected]>
> Cc: Wei Liu <[email protected]>
> Cc: Dexuan Cui <[email protected]>
> Cc: Lorenzo Pieralisi <[email protected]>
> Cc: "Krzysztof Wilczyński" <[email protected]>
> Cc: Rob Herring <[email protected]>
> Cc: Bjorn Helgaas <[email protected]>
> Cc: [email protected]
> Cc: [email protected]
> Signed-off-by: Kees Cook <[email protected]>

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

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
>
>

2023-10-14 19:43:03

by Krzysztof Wilczyński

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

Hello,

> 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

Applied to controller/hyperv, thank you!

[1/1] PCI: hv: Annotate struct hv_dr_state with __counted_by
https://git.kernel.org/pci/pci/c/45538f68b052

Krzysztof