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[21/21] dmaengine: usb-dmac: Annotate struct usb_dmac_desc with __counted_by

Message ID 20230817235859.49846-21-keescook@chromium.org (mailing list archive)
State Mainlined
Commit a04bbeaa37d8789de5592506fa776256e784b69c
Headers show
Series dmaengine: Annotate with __counted_by | expand

Commit Message

Kees Cook Aug. 17, 2023, 11:58 p.m. UTC
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 usb_dmac_desc.

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

Cc: Vinod Koul <vkoul@kernel.org>
Cc: Yu Kuai <yukuai3@huawei.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jordy Zomer <jordy@pwning.systems>
Cc: Jernej Skrabec <jernej.skrabec@gmail.com>
Cc: Tudor Ambarus <tudor.ambarus@linaro.org>
Cc: dmaengine@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
---
 drivers/dma/sh/usb-dmac.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Gustavo A. R. Silva Aug. 18, 2023, 2:17 a.m. UTC | #1
On 8/17/23 17:58, 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 usb_dmac_desc.
> 
> [1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci
> 
> Cc: Vinod Koul <vkoul@kernel.org>
> Cc: Yu Kuai <yukuai3@huawei.com>
> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> Cc: Jordy Zomer <jordy@pwning.systems>
> Cc: Jernej Skrabec <jernej.skrabec@gmail.com>
> Cc: Tudor Ambarus <tudor.ambarus@linaro.org>
> Cc: dmaengine@vger.kernel.org
> Signed-off-by: Kees Cook <keescook@chromium.org>

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

Thanks
--
Gustavo

> ---
>   drivers/dma/sh/usb-dmac.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/dma/sh/usb-dmac.c b/drivers/dma/sh/usb-dmac.c
> index b14cf350b669..4cfcd23e3268 100644
> --- a/drivers/dma/sh/usb-dmac.c
> +++ b/drivers/dma/sh/usb-dmac.c
> @@ -57,7 +57,7 @@ struct usb_dmac_desc {
>   	u32 residue;
>   	struct list_head node;
>   	dma_cookie_t done_cookie;
> -	struct usb_dmac_sg sg[];
> +	struct usb_dmac_sg sg[] __counted_by(sg_allocated_len);
>   };
>   
>   #define to_usb_dmac_desc(vd)	container_of(vd, struct usb_dmac_desc, vd)
diff mbox series

Patch

diff --git a/drivers/dma/sh/usb-dmac.c b/drivers/dma/sh/usb-dmac.c
index b14cf350b669..4cfcd23e3268 100644
--- a/drivers/dma/sh/usb-dmac.c
+++ b/drivers/dma/sh/usb-dmac.c
@@ -57,7 +57,7 @@  struct usb_dmac_desc {
 	u32 residue;
 	struct list_head node;
 	dma_cookie_t done_cookie;
-	struct usb_dmac_sg sg[];
+	struct usb_dmac_sg sg[] __counted_by(sg_allocated_len);
 };
 
 #define to_usb_dmac_desc(vd)	container_of(vd, struct usb_dmac_desc, vd)