[PATCH 12/14] net: openvswitch: Annotate struct dp_meter 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 dp_meter.

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

Cc: Pravin B Shelar <pshelar@xxxxxxx>
Cc: "David S. Miller" <davem@xxxxxxxxxxxxx>
Cc: Eric Dumazet <edumazet@xxxxxxxxxx>
Cc: Jakub Kicinski <kuba@xxxxxxxxxx>
Cc: Paolo Abeni <pabeni@xxxxxxxxxx>
Cc: netdev@xxxxxxxxxxxxxxx
Cc: dev@xxxxxxxxxxxxxxx
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
---
 net/openvswitch/meter.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/openvswitch/meter.h b/net/openvswitch/meter.h
index 013de694221f..ed11cd12b512 100644
--- a/net/openvswitch/meter.h
+++ b/net/openvswitch/meter.h
@@ -39,7 +39,7 @@ struct dp_meter {
 	u32 max_delta_t;
 	u64 used;
 	struct ovs_flow_stats stats;
-	struct dp_meter_band bands[];
+	struct dp_meter_band bands[] __counted_by(n_bands);
 };
 
 struct dp_meter_instance {
-- 
2.34.1