2023-09-22 21:12:42

by Kees Cook

Subject: [PATCH] soc: qcom: smem: Annotate struct qcom_smem 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 qcom_smem.

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

Cc: Andy Gross <[email protected]>
Cc: Bjorn Andersson <[email protected]>
Cc: Konrad Dybcio <[email protected]>
Cc: Nathan Chancellor <[email protected]>
Cc: Nick Desaulniers <[email protected]>
Cc: Tom Rix <[email protected]>
Cc: [email protected]
Cc: [email protected]
Signed-off-by: Kees Cook <[email protected]>
---
drivers/soc/qcom/smem.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/soc/qcom/smem.c b/drivers/soc/qcom/smem.c
index d4a89d2bb43b..4ce9cf1477ac 100644
--- a/drivers/soc/qcom/smem.c
+++ b/drivers/soc/qcom/smem.c
@@ -285,7 +285,7 @@ struct qcom_smem {
struct smem_partition partitions[SMEM_HOST_COUNT];

unsigned num_regions;
- struct smem_region regions[];
+ struct smem_region regions[] __counted_by(num_regions);
};

static void *
--
2.34.1

2023-09-28 00:33:07

by Bjorn Andersson

Subject: Re: [PATCH] soc: qcom: smem: Annotate struct qcom_smem with __counted_by

On Fri, 22 Sep 2023 10:54:14 -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 qcom_smem.
>
> [...]

Applied, thanks!

[1/1] soc: qcom: smem: Annotate struct qcom_smem with __counted_by
commit: 433ce46a97116f431ee114b4607143860aad4054

Best regards,
--
Bjorn Andersson <[email protected]>