[PATCH] memstick: jmb38x_ms: Annotate struct jmb38x_ms 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 jmb38x_ms.

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

Cc: Maxim Levitsky <maximlevitsky@xxxxxxxxx>
Cc: Alex Dubov <oakad@xxxxxxxxx>
Cc: Ulf Hansson <ulf.hansson@xxxxxxxxxx>
Cc: Tom Rix <trix@xxxxxxxxxx>
Cc: Len Baker <len.baker@xxxxxxx>
Cc: Dan Carpenter <error27@xxxxxxxxx>
Cc: "Gustavo A. R. Silva" <gustavoars@xxxxxxxxxx>
Cc: linux-mmc@xxxxxxxxxxxxxxx
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
---
 drivers/memstick/host/jmb38x_ms.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/memstick/host/jmb38x_ms.c b/drivers/memstick/host/jmb38x_ms.c
index 21cb2a786058..e77eb8b0eb12 100644
--- a/drivers/memstick/host/jmb38x_ms.c
+++ b/drivers/memstick/host/jmb38x_ms.c
@@ -66,7 +66,7 @@ struct jmb38x_ms_host {
 struct jmb38x_ms {
 	struct pci_dev        *pdev;
 	int                   host_cnt;
-	struct memstick_host  *hosts[];
+	struct memstick_host  *hosts[] __counted_by(host_cnt);
 };
 
 #define BLOCK_COUNT_MASK       0xffff0000
-- 
2.34.1