nexthop: Annotate struct nh_notifier_grp_info with __counted_by

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).

As found with Coccinelle[1], add __counted_by for struct nh_notifier_grp_info.

Cc: David Ahern <[email protected]>
Cc: "David S. Miller" <[email protected]>
Cc: Eric Dumazet <[email protected]>
Cc: Jakub Kicinski <[email protected]>
Cc: Paolo Abeni <[email protected]>
Cc: Nathan Chancellor <[email protected]>
Cc: Nick Desaulniers <[email protected]>
Cc: Tom Rix <[email protected]>
Cc: [email protected]
Cc: [email protected]
Link: https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci [1]
Signed-off-by: Kees Cook <[email protected]>
Reviewed-by: David Ahern <[email protected]>
Reviewed-by: Gustavo A. R. Silva <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

1 files changed, 1 insertions, 1 deletions

diff --git a/include/net/nexthop.h b/include/net/nexthop.h
index dbd90e8fe9d6..8f5a2ab45920 100644
--- a/include/net/nexthop.h
+++ b/include/net/nexthop.h
@@ -187,7 +187,7 @@ struct nh_notifier_grp_entry_info {
 struct nh_notifier_grp_info {
 	u16 num_nh;
 	bool is_fdb;
-	struct nh_notifier_grp_entry_info nh_entries[];
+	struct nh_notifier_grp_entry_info nh_entries[] __counted_by(num_nh);
 };
 
 struct nh_notifier_res_bucket_info {