On 10/4/23 01:18, 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 xfrm_sec_ctx.
Cc: Steffen Klassert <steffen.klass...@secunet.com>
Cc: Herbert Xu <herb...@gondor.apana.org.au>
Cc: "David S. Miller" <da...@davemloft.net>
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
---
include/uapi/linux/xfrm.h | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/include/uapi/linux/xfrm.h b/include/uapi/linux/xfrm.h
index 23543c33fee8..6a77328be114 100644
--- a/include/uapi/linux/xfrm.h
+++ b/include/uapi/linux/xfrm.h
@@ -4,6 +4,7 @@
#include <linux/in6.h>
#include <linux/types.h>
+#include <linux/stddef.h>
/* All of the structures in this file may not change size as they are
* passed into the kernel from userspace via netlink sockets.
@@ -33,7 +34,7 @@ struct xfrm_sec_ctx {
__u8 ctx_alg;
__u16 ctx_len;
__u32 ctx_sid;
- char ctx_str[];
+ char ctx_str[] __counted_by(ctx_len);
};
/* Security Context Domains of Interpretation */
