Re: [PATCH] i3c/master/mipi-i3c-hci: Annotate struct hci_rings_data with __counted_by

From: Gustavo A. R. Silva
Date: Sat Sep 23 2023 - 04:27:54 EST




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 hci_rings_data.

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

Cc: Alexandre Belloni <alexandre.belloni@xxxxxxxxxxx>
Cc: Nicolas Pitre <npitre@xxxxxxxxxxxx>
Cc: Len Baker <len.baker@xxxxxxx>
Cc: Boris Brezillon <boris.brezillon@xxxxxxxxxxxxx>
Cc: linux-i3c@xxxxxxxxxxxxxxxxxxx
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>

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

Thanks
--
Gustavo

---
drivers/i3c/master/mipi-i3c-hci/dma.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/i3c/master/mipi-i3c-hci/dma.c b/drivers/i3c/master/mipi-i3c-hci/dma.c
index 2990ac9eaade..a1ecdfc35641 100644
--- a/drivers/i3c/master/mipi-i3c-hci/dma.c
+++ b/drivers/i3c/master/mipi-i3c-hci/dma.c
@@ -139,7 +139,7 @@ struct hci_rh_data {
struct hci_rings_data {
unsigned int total;
- struct hci_rh_data headers[];
+ struct hci_rh_data headers[] __counted_by(total);
};
struct hci_dma_dev_ibi_data {