[PATCH] wifi: brcmfmac: firmware: Annotate struct brcmf_fw_request 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 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 brcmf_fw_request.

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

Cc: Arend van Spriel <aspriel@xxxxxxxxx>
Cc: Franky Lin <franky.lin@xxxxxxxxxxxx>
Cc: Hante Meuleman <hante.meuleman@xxxxxxxxxxxx>
Cc: Kalle Valo <kvalo@xxxxxxxxxx>
Cc: Matthias Brugger <mbrugger@xxxxxxxx>
Cc: Hector Martin <marcan@xxxxxxxxx>
Cc: "Alvin Šipraga" <alsi@xxxxxxxxxxxxxxx>
Cc: Hans de Goede <hdegoede@xxxxxxxxxx>
Cc: linux-wireless@xxxxxxxxxxxxxxx
Cc: brcm80211-dev-list.pdl@xxxxxxxxxxxx
Cc: SHA-cyfmac-dev-list@xxxxxxxxxxxx
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
---
 drivers/net/wireless/broadcom/brcm80211/brcmfmac/firmware.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/firmware.h b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/firmware.h
index 1266cbaee072..4002d326fd21 100644
--- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/firmware.h
+++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/firmware.h
@@ -69,7 +69,7 @@ struct brcmf_fw_request {
 	u16 bus_nr;
 	u32 n_items;
 	const char *board_types[BRCMF_FW_MAX_BOARD_TYPES];
-	struct brcmf_fw_item items[];
+	struct brcmf_fw_item items[] __counted_by(n_items);
 };
 
 struct brcmf_fw_name {
-- 
2.34.1