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[01/14] ipv4: Annotate struct fib_info with __counted_by

Message ID 20230922172858.3822653-1-keescook@chromium.org (mailing list archive)
State Not Applicable
Headers show
Series Batch 1: Annotate structs with __counted_by | expand

Commit Message

Kees Cook Sept. 22, 2023, 5:28 p.m. UTC
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 fib_info.

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

Cc: "David S. Miller" <davem@davemloft.net>
Cc: David Ahern <dsahern@kernel.org>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: netdev@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
---
 include/net/ip_fib.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Gustavo A. R. Silva Sept. 23, 2023, 1:43 a.m. UTC | #1
On 9/22/23 11:28, 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 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 fib_info.
> 
> [1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci
> 
> Cc: "David S. Miller" <davem@davemloft.net>
> Cc: David Ahern <dsahern@kernel.org>
> Cc: Eric Dumazet <edumazet@google.com>
> Cc: Jakub Kicinski <kuba@kernel.org>
> Cc: Paolo Abeni <pabeni@redhat.com>
> Cc: netdev@vger.kernel.org
> Signed-off-by: Kees Cook <keescook@chromium.org>

Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org>

Thanks
diff mbox series

Patch

diff --git a/include/net/ip_fib.h b/include/net/ip_fib.h
index f0c13864180e..84b0a82c9df4 100644
--- a/include/net/ip_fib.h
+++ b/include/net/ip_fib.h
@@ -156,7 +156,7 @@  struct fib_info {
 	bool			nh_updated;
 	struct nexthop		*nh;
 	struct rcu_head		rcu;
-	struct fib_nh		fib_nh[];
+	struct fib_nh		fib_nh[] __counted_by(fib_nhs);
 };