[PATCH v2] wifi: p54: Annotate struct p54_cal_database with __counted_by

[Kees Cook]

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 via CONFIG_UBSAN_BOUNDS (for
array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family
functions).

Add __counted_by for struct p54_cal_database.

Cc: Christian Lamparter <chunkeey@xxxxxxxxxxxxxx>
Cc: Kalle Valo <kvalo@xxxxxxxxxx>
Cc: "Gustavo A. R. Silva" <gustavoars@xxxxxxxxxx>
Cc: linux-wireless@xxxxxxxxxxxxxxx
Cc: linux-hardening@xxxxxxxxxxxxxxx
Suggested-by: Jason Andryuk <jandryuk@xxxxxxxxx>
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
---
v1 - https://lore.kernel.org/all/20231006201719.work.356-kees@xxxxxxxxxx/
v2 - use the correct member (jandryuk)
---
 drivers/net/wireless/intersil/p54/p54.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/wireless/intersil/p54/p54.h b/drivers/net/wireless/intersil/p54/p54.h
index 3356ea708d81..522656de4159 100644
--- a/drivers/net/wireless/intersil/p54/p54.h
+++ b/drivers/net/wireless/intersil/p54/p54.h
@@ -126,7 +126,7 @@ struct p54_cal_database {
 	size_t entry_size;
 	size_t offset;
 	size_t len;
-	u8 data[];
+	u8 data[] __counted_by(len);
 };
 
 #define EEPROM_READBACK_LEN 0x3fc
-- 
2.34.1