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netfilter: nf_tables: Annotate struct nft_pipapo_match with __counted_by

PATCH In review Kees Cook 2 participants 2 messages Oct 3, 2023

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Kees Cook

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#0 lore raw

PATCH 1/1 netfilter: nf_tables: Annotate struct nft_pipapo_match 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 nft_pipapo_match.

Cc Pablo Neira Ayuso <[email protected]>
Cc Jozsef Kadlecsik <[email protected]>
Cc Florian Westphal <[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]
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]>
---
 net/netfilter/nft_set_pipapo.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
net/netfilter/nft_set_pipapo.h +1 -1
index 25a75591583e..2e164a319945 100644
@@ -147,7 +147,7 @@ struct nft_pipapo_match {
 	unsigned long * __percpu *scratch;
 	size_t bsize_max;
 	struct rcu_head rcu;
-	struct nft_pipapo_field f[];
+	struct nft_pipapo_field f[] __counted_by(field_count);
 };
 
 /**
Signature · 1 line
2.34.1
Reviewed-by on v1 1/1
#1 lore raw
Quoted 8 lines · 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 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 nft_pipapo_match.

Quoted 12 lines
Cc Pablo Neira Ayuso <[email protected]>
Cc Jozsef Kadlecsik <[email protected]>
Cc Florian Westphal <[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]
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 Gustavo A. R. Silva <[email protected]>

Thanks
--
Gustavo

Quoted 17 lines
---
  net/netfilter/nft_set_pipapo.h | 2 +-
  1 file changed, 1 insertion(+), 1 deletion(-)
net/netfilter/nft_set_pipapo.h +1 -1
index 25a75591583e..2e164a319945 100644
@@ -147,7 +147,7 @@ struct nft_pipapo_match {
  	unsigned long * __percpu *scratch;
  	size_t bsize_max;
  	struct rcu_head rcu;
-	struct nft_pipapo_field f[];
+	struct nft_pipapo_field f[] __counted_by(field_count);
  };
 
  /**