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 <[email protected]>
Cc: "David S. Miller" <[email protected]>
Cc: Eric Dumazet <[email protected]>
Cc: Jakub Kicinski <[email protected]>
Cc: Paolo Abeni <[email protected]>
Cc: [email protected]
Cc: [email protected]
Signed-off-by: Kees Cook <[email protected]>
---
 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


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