2023-09-22 20:07:46

by Kees Cook

Subject: [PATCH] mfd: iqs62x: Annotate struct iqs62x_fw_blk 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 iqs62x_fw_blk.

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

Cc: Lee Jones <[email protected]>
Signed-off-by: Kees Cook <[email protected]>
---
drivers/mfd/iqs62x.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/mfd/iqs62x.c b/drivers/mfd/iqs62x.c
index e03b4d38fbb0..1b465590567c 100644
--- a/drivers/mfd/iqs62x.c
+++ b/drivers/mfd/iqs62x.c
@@ -96,7 +96,7 @@ struct iqs62x_fw_blk {
u8 addr;
u8 mask;
u8 len;
- u8 data[];
+ u8 data[] __counted_by(len);
};

struct iqs62x_info {
--
2.34.1

2023-09-24 01:41:44

by Gustavo A. R. Silva

Subject: Re: [PATCH] mfd: iqs62x: Annotate struct iqs62x_fw_blk 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 iqs62x_fw_blk.
>
> [1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci
>
> Cc: Lee Jones <[email protected]>
> Signed-off-by: Kees Cook <[email protected]>

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

Thanks
--
Gustavo

> ---
> drivers/mfd/iqs62x.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/mfd/iqs62x.c b/drivers/mfd/iqs62x.c
> index e03b4d38fbb0..1b465590567c 100644
> --- a/drivers/mfd/iqs62x.c
> +++ b/drivers/mfd/iqs62x.c
> @@ -96,7 +96,7 @@ struct iqs62x_fw_blk {
> u8 addr;
> u8 mask;
> u8 len;
> - u8 data[];
> + u8 data[] __counted_by(len);
> };
>
> struct iqs62x_info {

2023-09-28 13:26:48

by Lee Jones

Subject: Re: (subset) [PATCH] mfd: iqs62x: Annotate struct iqs62x_fw_blk with __counted_by

On Fri, 22 Sep 2023 10:53:38 -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 iqs62x_fw_blk.
>
> [...]

Applied, thanks!

[1/1] mfd: iqs62x: Annotate struct iqs62x_fw_blk with __counted_by
commit: d25fad59146b4fb24f690bc0bedd32a299bc1541

--
Lee Jones [李琼斯]