2023-10-06 20:17:56

by Kees Cook

Subject: [PATCH] mtd: rawnand: Annotate struct mtk_nfc_nand_chip 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 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
mtk_nfc_nand_chip.

Cc: Miquel Raynal <[email protected]>
Cc: Richard Weinberger <[email protected]>
Cc: Vignesh Raghavendra <[email protected]>
Cc: Matthias Brugger <[email protected]>
Cc: AngeloGioacchino Del Regno <[email protected]>
Cc: "Gustavo A. R. Silva" <[email protected]>
Cc: Heiko Stuebner <[email protected]>
Cc: Martin Blumenstingl <[email protected]>
Cc: Thierry Reding <[email protected]>
Cc: Roger Quadros <[email protected]>
Cc: "Uwe Kleine-König" <[email protected]>
Cc: Cai Huoqing <[email protected]>
Cc: Chuanhong Guo <[email protected]>
Cc: Rob Herring <[email protected]>
Cc: Li Zetao <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Link: https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci [1]
Signed-off-by: Kees Cook <[email protected]>
---
drivers/mtd/nand/raw/mtk_nand.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/mtd/nand/raw/mtk_nand.c b/drivers/mtd/nand/raw/mtk_nand.c
index 29c8bddde67f..60198e33d2d5 100644
--- a/drivers/mtd/nand/raw/mtk_nand.c
+++ b/drivers/mtd/nand/raw/mtk_nand.c
@@ -130,7 +130,7 @@ struct mtk_nfc_nand_chip {
u32 spare_per_sector;

int nsels;
- u8 sels[];
+ u8 sels[] __counted_by(nsels);
/* nothing after this field */
};

--
2.34.1

2023-10-06 23:02:59

by Gustavo A. R. Silva

Subject: Re: [PATCH] mtd: rawnand: Annotate struct mtk_nfc_nand_chip with __counted_by

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
> mtk_nfc_nand_chip.
>
> Cc: Miquel Raynal <[email protected]>
> Cc: Richard Weinberger <[email protected]>
> Cc: Vignesh Raghavendra <[email protected]>
> Cc: Matthias Brugger <[email protected]>
> Cc: AngeloGioacchino Del Regno <[email protected]>
> Cc: "Gustavo A. R. Silva" <[email protected]>
> Cc: Heiko Stuebner <[email protected]>
> Cc: Martin Blumenstingl <[email protected]>
> Cc: Thierry Reding <[email protected]>
> Cc: Roger Quadros <[email protected]>
> Cc: "Uwe Kleine-König" <[email protected]>
> Cc: Cai Huoqing <[email protected]>
> Cc: Chuanhong Guo <[email protected]>
> Cc: Rob Herring <[email protected]>
> Cc: Li Zetao <[email protected]>
> Cc: [email protected]
> Cc: [email protected]
> Cc: [email protected]
> Cc: [email protected]
> Link: https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci [1]
> Signed-off-by: Kees Cook <[email protected]>

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

Thanks!
--
Gustavo

> ---
> drivers/mtd/nand/raw/mtk_nand.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/mtd/nand/raw/mtk_nand.c b/drivers/mtd/nand/raw/mtk_nand.c
> index 29c8bddde67f..60198e33d2d5 100644
> --- a/drivers/mtd/nand/raw/mtk_nand.c
> +++ b/drivers/mtd/nand/raw/mtk_nand.c
> @@ -130,7 +130,7 @@ struct mtk_nfc_nand_chip {
> u32 spare_per_sector;
>
> int nsels;
> - u8 sels[];
> + u8 sels[] __counted_by(nsels);
> /* nothing after this field */
> };
>

2023-10-16 09:29:48

by Miquel Raynal

Subject: Re: [PATCH] mtd: rawnand: Annotate struct mtk_nfc_nand_chip with __counted_by

On Fri, 2023-10-06 at 20:17:28 UTC, 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
> mtk_nfc_nand_chip.
>
> Cc: Miquel Raynal <[email protected]>
> Cc: Richard Weinberger <[email protected]>
> Cc: Vignesh Raghavendra <[email protected]>
> Cc: Matthias Brugger <[email protected]>
> Cc: AngeloGioacchino Del Regno <[email protected]>
> Cc: "Gustavo A. R. Silva" <[email protected]>
> Cc: Heiko Stuebner <[email protected]>
> Cc: Martin Blumenstingl <[email protected]>
> Cc: Thierry Reding <[email protected]>
> Cc: Roger Quadros <[email protected]>
> Cc: "Uwe Kleine-König" <[email protected]>
> Cc: Cai Huoqing <[email protected]>
> Cc: Chuanhong Guo <[email protected]>
> Cc: Rob Herring <[email protected]>
> Cc: Li Zetao <[email protected]>
> Cc: [email protected]
> Cc: [email protected]
> Cc: [email protected]
> Cc: [email protected]
> Link: https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci [1]
> Signed-off-by: Kees Cook <[email protected]>
> Reviewed-by: Gustavo A. R. Silva <[email protected]>

Applied to https://git.kernel.org/pub/scm/linux/kernel/git/mtd/linux.git nand/next, thanks.

Miquel