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 zynqmp_ipi_pdata.
[1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci
Cc: Jassi Brar <[email protected]>
Cc: Michal Simek <[email protected]>
Cc: [email protected]
Signed-off-by: Kees Cook <[email protected]>
---
drivers/mailbox/zynqmp-ipi-mailbox.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/mailbox/zynqmp-ipi-mailbox.c b/drivers/mailbox/zynqmp-ipi-mailbox.c
index e4fcac97dbfa..7fa533e80dd9 100644
--- a/drivers/mailbox/zynqmp-ipi-mailbox.c
+++ b/drivers/mailbox/zynqmp-ipi-mailbox.c
@@ -108,7 +108,7 @@ struct zynqmp_ipi_pdata {
unsigned int method;
u32 local_id;
int num_mboxes;
- struct zynqmp_ipi_mbox ipi_mboxes[];
+ struct zynqmp_ipi_mbox ipi_mboxes[] __counted_by(num_mboxes);
};
static struct device_driver zynqmp_ipi_mbox_driver = {
--
2.34.1
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 zynqmp_ipi_pdata.
>
> [1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci
>
> Cc: Jassi Brar <[email protected]>
> Cc: Michal Simek <[email protected]>
> Cc: [email protected]
> Signed-off-by: Kees Cook <[email protected]>
Reviewed-by: Gustavo A. R. Silva <[email protected]>
Thanks
--
Gustavo
> ---
> drivers/mailbox/zynqmp-ipi-mailbox.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/mailbox/zynqmp-ipi-mailbox.c b/drivers/mailbox/zynqmp-ipi-mailbox.c
> index e4fcac97dbfa..7fa533e80dd9 100644
> --- a/drivers/mailbox/zynqmp-ipi-mailbox.c
> +++ b/drivers/mailbox/zynqmp-ipi-mailbox.c
> @@ -108,7 +108,7 @@ struct zynqmp_ipi_pdata {
> unsigned int method;
> u32 local_id;
> int num_mboxes;
> - struct zynqmp_ipi_mbox ipi_mboxes[];
> + struct zynqmp_ipi_mbox ipi_mboxes[] __counted_by(num_mboxes);
> };
>
> static struct device_driver zynqmp_ipi_mbox_driver = {
On 9/22/23 19:53, 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 zynqmp_ipi_pdata.
>
> [1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci
>
> Cc: Jassi Brar <[email protected]>
> Cc: Michal Simek <[email protected]>
> Cc: [email protected]
> Signed-off-by: Kees Cook <[email protected]>
> ---
> drivers/mailbox/zynqmp-ipi-mailbox.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/mailbox/zynqmp-ipi-mailbox.c b/drivers/mailbox/zynqmp-ipi-mailbox.c
> index e4fcac97dbfa..7fa533e80dd9 100644
> --- a/drivers/mailbox/zynqmp-ipi-mailbox.c
> +++ b/drivers/mailbox/zynqmp-ipi-mailbox.c
> @@ -108,7 +108,7 @@ struct zynqmp_ipi_pdata {
> unsigned int method;
> u32 local_id;
> int num_mboxes;
> - struct zynqmp_ipi_mbox ipi_mboxes[];
> + struct zynqmp_ipi_mbox ipi_mboxes[] __counted_by(num_mboxes);
> };
>
> static struct device_driver zynqmp_ipi_mbox_driver = {
Acked-by: Michal Simek <[email protected]>
Thanks,
Michal
On Fri, Sep 22, 2023 at 10:54 AM Kees Cook <[email protected]> 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 zynqmp_ipi_pdata.
>
> [1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci
>
> Cc: Jassi Brar <[email protected]>
> Cc: Michal Simek <[email protected]>
> Cc: [email protected]
> Signed-off-by: Kees Cook <[email protected]>
> ---
Great patch! Crucially, the count is _correctly_ assigned
to before the flexible array member is accessed.
Reviewed-by: Justin Stitt <[email protected]>
> drivers/mailbox/zynqmp-ipi-mailbox.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/mailbox/zynqmp-ipi-mailbox.c b/drivers/mailbox/zynqmp-ipi-mailbox.c
> index e4fcac97dbfa..7fa533e80dd9 100644
> --- a/drivers/mailbox/zynqmp-ipi-mailbox.c
> +++ b/drivers/mailbox/zynqmp-ipi-mailbox.c
> @@ -108,7 +108,7 @@ struct zynqmp_ipi_pdata {
> unsigned int method;
> u32 local_id;
> int num_mboxes;
> - struct zynqmp_ipi_mbox ipi_mboxes[];
> + struct zynqmp_ipi_mbox ipi_mboxes[] __counted_by(num_mboxes);
> };
>
> static struct device_driver zynqmp_ipi_mbox_driver = {
> --
> 2.34.1
>
>
Thanks
Justin
On Fri, 22 Sep 2023 10:53:51 -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 zynqmp_ipi_pdata.
>
> [...]
Applied to for-next/hardening, thanks!
[1/1] mailbox: zynqmp: Annotate struct zynqmp_ipi_pdata with __counted_by
https://git.kernel.org/kees/c/6b607a3a311a
Take care,
--
Kees Cook