From: Kees Cook Date: Mon, 13 Dec 2021 22:33:23 +0000 (-0800) Subject: RDMA/mlx5: Use memset_after() to zero struct mlx5_ib_mr X-Git-Tag: v5.17-rc1~89^2~34 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=e517f76a3cb24b2a4749e0348390aece24cf9925;p=thirdparty%2Fkernel%2Flinux.git RDMA/mlx5: Use memset_after() to zero struct mlx5_ib_mr In preparation for FORTIFY_SOURCE performing compile-time and run-time field bounds checking for memset(), avoid intentionally writing across neighboring fields. Use memset_after() to zero the end of struct mlx5_ib_mr that should be initialized. Link: https://lore.kernel.org/r/20211213223331.135412-10-keescook@chromium.org Acked-by: Leon Romanovsky Signed-off-by: Kees Cook Signed-off-by: Jason Gunthorpe --- diff --git a/drivers/infiniband/hw/mlx5/mlx5_ib.h b/drivers/infiniband/hw/mlx5/mlx5_ib.h index 4a7a56ed740b9..ded10719b6437 100644 --- a/drivers/infiniband/hw/mlx5/mlx5_ib.h +++ b/drivers/infiniband/hw/mlx5/mlx5_ib.h @@ -664,8 +664,8 @@ struct mlx5_ib_mr { /* User MR data */ struct mlx5_cache_ent *cache_ent; + /* Everything after cache_ent is zero'd when MR allocated */ - /* This is zero'd when the MR is allocated */ union { /* Used only while the MR is in the cache */ struct { @@ -718,7 +718,7 @@ struct mlx5_ib_mr { /* Zero the fields in the mr that are variant depending on usage */ static inline void mlx5_clear_mr(struct mlx5_ib_mr *mr) { - memset(mr->out, 0, sizeof(*mr) - offsetof(struct mlx5_ib_mr, out)); + memset_after(mr, 0, cache_ent); } static inline bool is_odp_mr(struct mlx5_ib_mr *mr)