On Tue, Dec 07, 2021 at 01:20:22PM -0800, Kees Cook wrote: > 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. > > Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx> Reviewed-by: Gustavo A. R. Silva <gustavoars@xxxxxxxxxx> Thanks -- Gustavo > --- > v2: rebased, umem moved into the union and is expected to be wiped > https://lore.kernel.org/lkml/20211207194525.GL6385@xxxxxxxxxx > --- > drivers/infiniband/hw/mlx5/mlx5_ib.h | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/infiniband/hw/mlx5/mlx5_ib.h b/drivers/infiniband/hw/mlx5/mlx5_ib.h > index 4a7a56ed740b..ded10719b643 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) > -- > 2.30.2 > > > >
