Re: [PATCH] firewire: Annotate struct fw_node with __counted_by

From: Gustavo A. R. Silva
Date: Sat Sep 23 2023 - 19:02:04 EST




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 fw_node.

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

Cc: Takashi Sakamoto <o-takashi@xxxxxxxxxxxxx>
Cc: linux1394-devel@xxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>

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

Thanks
--
Gustavo

---
drivers/firewire/core.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/firewire/core.h b/drivers/firewire/core.h
index 2a05f411328f..95c10f3d2282 100644
--- a/drivers/firewire/core.h
+++ b/drivers/firewire/core.h
@@ -191,7 +191,7 @@ struct fw_node {
/* Upper layer specific data. */
void *data;
- struct fw_node *ports[];
+ struct fw_node *ports[] __counted_by(port_count);
};
static inline struct fw_node *fw_node_get(struct fw_node *node)