On 10/4/23 01:17, Kees Cook wrote:
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 packet_fanout.
Cc: "David S. Miller" <da...@davemloft.net>
Cc: Eric Dumazet <eduma...@google.com>
Cc: Jakub Kicinski <k...@kernel.org>
Cc: Paolo Abeni <pab...@redhat.com>
Cc: Willem de Bruijn <will...@google.com>
Cc: Anqi Shen <amy....@antgroup.com>
Cc: net...@vger.kernel.org
Link:
https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci
[1]
Signed-off-by: Kees Cook <keesc...@chromium.org>
Reviewed-by: Gustavo A. R. Silva <gustavo...@kernel.org>
Thanks
--
Gustavo
---
net/packet/internal.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/net/packet/internal.h b/net/packet/internal.h
index 63f4865202c1..d29c94c45159 100644
--- a/net/packet/internal.h
+++ b/net/packet/internal.h
@@ -94,7 +94,7 @@ struct packet_fanout {
spinlock_t lock;
refcount_t sk_ref;
struct packet_type prot_hook ____cacheline_aligned_in_smp;
- struct sock __rcu *arr[];
+ struct sock __rcu *arr[] __counted_by(max_num_members);
};
struct packet_rollover {
