Re: [PATCH] ceph: Annotate struct ceph_osd_request with __counted_by

From: Xiubo Li
Date: Sun Sep 17 2023 - 20:30:35 EST



On 9/16/23 04:15, 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 ceph_osd_request.

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

Cc: Ilya Dryomov <idryomov@xxxxxxxxx>
Cc: Xiubo Li <xiubli@xxxxxxxxxx>
Cc: Jeff Layton <jlayton@xxxxxxxxxx>
Cc: ceph-devel@xxxxxxxxxxxxxxx
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
---
include/linux/ceph/osd_client.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/linux/ceph/osd_client.h b/include/linux/ceph/osd_client.h
index bf9823956758..b8610e9d2471 100644
--- a/include/linux/ceph/osd_client.h
+++ b/include/linux/ceph/osd_client.h
@@ -278,7 +278,7 @@ struct ceph_osd_request {
int r_attempts;
u32 r_map_dne_bound;
- struct ceph_osd_req_op r_ops[];
+ struct ceph_osd_req_op r_ops[] __counted_by(r_num_ops);
};
struct ceph_request_redirect {

Reviewed-by: Xiubo Li <xiubli@xxxxxxxxxx>

Thanks!

- Xiubo