2023-09-23 01:25:37

by Kees Cook

Subject: [PATCH] firewire: Annotate struct fw_node 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 fw_node.

[1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci

Cc: Takashi Sakamoto <[email protected]>
Cc: [email protected]
Signed-off-by: Kees Cook <[email protected]>
---
drivers/firewire/core.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/firewire/core.h b/drivers/firewire/core.h
index 2a05f411328f..95c10f3d2282 100644
--- a/drivers/firewire/core.h
+++ b/drivers/firewire/core.h
@@ -191,7 +191,7 @@ struct fw_node {
/* Upper layer specific data. */
void *data;

- struct fw_node *ports[];
+ struct fw_node *ports[] __counted_by(port_count);
};

static inline struct fw_node *fw_node_get(struct fw_node *node)
--
2.34.1

2023-09-23 23:02:21

by Gustavo A. R. Silva

Subject: Re: [PATCH] firewire: Annotate struct fw_node with __counted_by

On 9/22/23 11:53, 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 fw_node.
>
> [1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci
>
> Cc: Takashi Sakamoto <[email protected]>
> Cc: [email protected]
> Signed-off-by: Kees Cook <[email protected]>

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

Thanks
--
Gustavo

> ---
> drivers/firewire/core.h | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/firewire/core.h b/drivers/firewire/core.h
> index 2a05f411328f..95c10f3d2282 100644
> --- a/drivers/firewire/core.h
> +++ b/drivers/firewire/core.h
> @@ -191,7 +191,7 @@ struct fw_node {
> /* Upper layer specific data. */
> void *data;
>
> - struct fw_node *ports[];
> + struct fw_node *ports[] __counted_by(port_count);
> };
>
> static inline struct fw_node *fw_node_get(struct fw_node *node)

2023-09-24 15:11:03

by Takashi Sakamoto

Subject: Re: [PATCH] firewire: Annotate struct fw_node with __counted_by

Hi,

On Fri, Sep 22, 2023 at 10:53:35AM -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 fw_node.
>
> [1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci
>
> Cc: Takashi Sakamoto <[email protected]>
> Cc: [email protected]
> Signed-off-by: Kees Cook <[email protected]>
> ---
> drivers/firewire/core.h | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)

Applied to for-next branch, thanks.


Regards

Takashi Sakamoto