2023-09-22 19:58:46

by Kees Cook

Subject: [PATCH] i3c: master: cdns: Annotate struct cdns_i3c_xfer 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 cdns_i3c_xfer.

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

Cc: "Przemysław Gaj" <[email protected]>
Cc: Alexandre Belloni <[email protected]>
Cc: [email protected]
Signed-off-by: Kees Cook <[email protected]>
---
drivers/i3c/master/i3c-master-cdns.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/i3c/master/i3c-master-cdns.c b/drivers/i3c/master/i3c-master-cdns.c
index 49551db71bc9..97c1010956a0 100644
--- a/drivers/i3c/master/i3c-master-cdns.c
+++ b/drivers/i3c/master/i3c-master-cdns.c
@@ -387,7 +387,7 @@ struct cdns_i3c_xfer {
struct completion comp;
int ret;
unsigned int ncmds;
- struct cdns_i3c_cmd cmds[];
+ struct cdns_i3c_cmd cmds[] __counted_by(ncmds);
};

struct cdns_i3c_data {
--
2.34.1

2023-09-23 08:28:07

by Gustavo A. R. Silva

Subject: Re: [PATCH] i3c: master: cdns: Annotate struct cdns_i3c_xfer with __counted_by

On 9/22/23 11:50, 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 cdns_i3c_xfer.
>
> [1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci
>
> Cc: "Przemysław Gaj" <[email protected]>
> Cc: Alexandre Belloni <[email protected]>
> Cc: [email protected]
> Signed-off-by: Kees Cook <[email protected]>

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

Thanks
--
Gustavo

> ---
> drivers/i3c/master/i3c-master-cdns.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/i3c/master/i3c-master-cdns.c b/drivers/i3c/master/i3c-master-cdns.c
> index 49551db71bc9..97c1010956a0 100644
> --- a/drivers/i3c/master/i3c-master-cdns.c
> +++ b/drivers/i3c/master/i3c-master-cdns.c
> @@ -387,7 +387,7 @@ struct cdns_i3c_xfer {
> struct completion comp;
> int ret;
> unsigned int ncmds;
> - struct cdns_i3c_cmd cmds[];
> + struct cdns_i3c_cmd cmds[] __counted_by(ncmds);
> };
>
> struct cdns_i3c_data {

2023-09-26 01:50:23

by Alexandre Belloni

Subject: Re: [PATCH] i3c: master: cdns: Annotate struct cdns_i3c_xfer with __counted_by

On Fri, 22 Sep 2023 10:50:15 -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 cdns_i3c_xfer.
>
> [...]

Applied, thanks!

[1/1] i3c: master: cdns: Annotate struct cdns_i3c_xfer with __counted_by
commit: 49f33846efc079eb94b044bf897e90909fd3aa11

Best regards,

--
Alexandre Belloni, co-owner and COO, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com